[HN Gopher] Chainless electric drive system "Free Drive" for bic...
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Chainless electric drive system "Free Drive" for bicycles (2021)
Author : Tomte
Score : 89 points
Date : 2022-05-13 12:33 UTC (10 hours ago)
(HTM) web link (www.schaeffler.de)
(TXT) w3m dump (www.schaeffler.de)
| msandford wrote:
| I'd be more interested as an alternative to chain or belt drives
| but I'm not sure how you incorporate gearing without power
| electronics. Chains can be up to 98% efficient and I'd prefer not
| to throw away 10% just to eliminate gears.
| sorenjan wrote:
| It's worth noting the "up to" part. Well maintained and cleaned
| chains are effective, but I would guess that a lot of commuter
| bikes have dirty, rusty, and worn chains that lose with a lot
| of efficiency. Couple that with poorly maintained and adjusted
| gears and alternatives might not be far off in efficiency if
| they're a closed system with less maintenance requirements.
| KennyBlanken wrote:
| I don't have a link handy but the difference between a
| perfectly maintained chain and a dry, poor condition chain is
| not as significant as people think.
|
| Also, many, many transportation bicycles have chain cases,
| which is much simpler than a motor-generator system.
| SigmundA wrote:
| Let's not forget about belt drives as well which are
| becoming more popular due to no need for maintenance while
| still having great efficiency.
| alex_duf wrote:
| You also have to take into account the extra weight of having
| a dynamo + a motor, I doubt it's more advantageous than a
| chain on a classic bicycle.
|
| For an electric bicycle though, I see it as a really good
| contender
| sorenjan wrote:
| Yes, this particular system is probably far from efficient
| enough for regular bikes, this is more for larger
| transportation bikes and similar (like this example [0]).
| Having a chain on those limits their construction options,
| and they're already electric anyway.
|
| I was referring to different types of gears and power
| transfer like driveshafts or hydraulics [1], if you can
| make it perform at a consistent 90% efficiency it might
| beat chain drive in practice even though it shouldn't in
| theory.
|
| [0] https://youtu.be/N02KMeOkevI?t=81
|
| [1] https://www.youtube.com/watch?v=NTB7XOQA-XQ
| test6554 wrote:
| I'm not sure how this system works, but it seems like
| adding in battery power might be useful.
| alex_duf wrote:
| I'm assuming it was suggested to replace a chain by what
| is essentially a dynamo + motor.
|
| You pedal to generate energy, and move that energy to the
| wheel through wire and another motor. (I'm not saying
| this is a good idea, just describing what I understood).
|
| I'm curious what sort of efficiency you can expect on a
| ridiculous system like that.
| svnpenn wrote:
| With these, you could store energy by pedaling, even when going
| downhill. If you pedal downhill with a chain, that's just
| wasted energy.
| samstave wrote:
| Unless you downshift and peddle hard to gain a lot of speed
| :-)
| a4isms wrote:
| You're joking, but to answer the question seriously, the
| problem with slamming it into your biggest gear and
| pedalling downhill is that wind resistance increases with
| the square of your velocity.
|
| When going downhill, you are going faster thanks to
| gravity. A small increase in speed requires a
| disproportionally large increase in effort. Hand-waving
| over the inefficiencies involved in an electric power
| train, you are far better off pedalling and storing the
| energy on the downhill, then "spending" that stored energy
| on the flats or even saving it for the next uphill.
|
| With respect to going downhill faster with this system, I
| doubt it can do anything useful in a straight line descent,
| but in a long, switchback descent of the type seen in the
| big Grand Tour races on mountain stages, cyclists need to
| brake into the switchbacks and accelerate out of them.
|
| Regenerative braking followed by assisted pedalling out of
| the corners would be a huge win.
| samstave wrote:
| > _"...The problem with slamming it into your biggest
| gear and pedalling downhill is that wind resistance
| increases with the square of your velocity._ "
|
| -- Are you much of a biker? (I put on around ~1,000 miles
| a month on a 29" mtn bike.
|
| Knobby tires and all.
|
| At no point ever have I worried about wind resistance -
| and im not a "shave my legs tour de france" (my brother
| is, but hes an ultra athelete-type-A Doctor) type that
| worries about my grams per component, corporate spandex
| or $12,000 week-end ride.
|
| So, while you may be "technically correct" you're
| commenting as "functionally illiterate"
| a4isms wrote:
| I really don't want this to devolve into chest-pounding,
| but I have worked in the bike industry, and have raced
| on-and-off as an amateur in road, cyclocross, MTB, and
| duathlon dating back to the late 80s. I remember when the
| Ritchey P23 was the state-of-the-art in lightweight
| mountain biking, something I chuckled at when riding a 17
| pound carbon Ibis a couple of decades later.
|
| Wind resistance absolutely matters in every discipline of
| cycling, and you don't need to have been fooling around
| with bikes for forty years to know that. If it didn't
| matter, what are all those triathletes and time trialists
| doing with aero bars, flat backs, and disc wheels?
|
| It matters in MTB as well. The optimal position for
| efficiently generating power on a bicycle is actually
| quite upright, you can see this if you look at pictures
| of people riding "roller races," they usually flipped
| their handlebars up so they could be much more upright
| than when riding on a track.
|
| XC MTBs have much lower bars than would be most efficient
| on rollers without wind resistance, and that's because
| the lower position generates less drag, knobby tires and
| all.
|
| Even if you aren't riding a time trial or racing XC on an
| MTB, knowing where to expend your energy and where to
| save it matters greatly. If your daily commute involves
| hills, you will work less and arrive sooner if you don't
| try to crank your max while descending, and save your
| efforts for climbing.
|
| That's just math and physics.
|
| ---
|
| Also, please, I'm not upset at any random internet person
| using insulting language, but it is not constructive for
| our community to go around suggesting other users are
| "functionally illiterate."
| Steltek wrote:
| Mountain bike descents and road bike descents are
| dramatically different things.
| samstave wrote:
| Find me a road bike with an electric motor.
| a4isms wrote:
| They exist, and that's why UCI scan bikes at the race
| start line for electric motors, it's a serious enough
| problem that it has a name, "Motor doping." Famously,
| Femke van den Driessche received a six-year ban after
| being caught motor-doping in cyclocross.
|
| https://www.bbc.com/sport/cycling/36142963
|
| If you don't want to cheat with a motor, bicycle stores
| sell all kinds of road bikes with pedal assist for non-
| competitive riding. Trek, for example, make several
| e-assist versions of their Domane road bikes:
|
| https://www.trekbikes.com/us/en_US/ebike_collection/
| a4isms wrote:
| > Regenerative braking followed by assisted pedalling out
| of the corners would be a huge win.
|
| ...Until the next ascent, where you have to haul the
| weight of the battery and what amounts to two electric
| motors uphill...
|
| Although it seems sacrilegious to imagine energy-recovery
| units in UCI bicycle racing, innovation is strongly
| influenced by the big manufacturers who are trying to
| sell bikes.
|
| It's unlikely there will be a UCI-sanctioned ERU any time
| soon, but if there was, the key to adoption would
| probably be the UCI minimum weight regulations. We are
| now at the point where high-end bikes often need weights
| added to meet the minimum, and if the rest of the bike
| ever gets light enough, it could be possible to add an
| ERU without compromising the total weight for climbing.
|
| But that would require breakthroughs in the culture of
| bicycle racing and multiple technologies.
| markvdb wrote:
| This system enables regenerative braking on bicycles. That
| means you also gain a lot...
|
| What I would love to see though would be this, applied to a
| recumbent or a velomobile. Those often have atypically long
| chains.
| mikepurvis wrote:
| Would be a game-changer for urban riding, being able to
| quickly reclaim energy after a stop.
| jeffbee wrote:
| There already were regenerative electric bikes. The first-
| generation Specialized Turbo had regeneration linked to the
| brake levers, and nobody cared. Not worth the complexity.
|
| Later Specialized bikes have a regen mode you can engage
| manually but it's still basically never worth it.
| wolverine876 wrote:
| Why isn't it worth it? It seems like free energy. Or is the
| weight a problem?
| dreamcompiler wrote:
| Regenerative braking makes a lot of sense on cars because
| cars are not very weight-sensitive and more weight works in
| your favor for regen braking.
|
| Regen braking makes much less sense on bikes because bikes
| are weight-sensitive.
|
| https://gocarlite.com/electric-bicycle-regenerative-braking/
| dahfizz wrote:
| That blog post is pretty misguided, IMO. I'll assume the
| math is right, and the potential gain from regen braking is
| small. But it's _free_!
|
| > The way regenerative braking is implemented is to have
| the motor continuously engaged.
|
| This is wrong. Regen braking only requires the motor be
| engaged _when braking_. There's no reason you can't coast
| when you want to coast.
| Tostino wrote:
| You are absolutely right about it being small, but free.
|
| Do keep in mind, a direct drive is always "engaged" to
| some extent by the cogging force. An advanced controller
| can make a direct drives "freewheel", but it actually
| takes power to do that. Totally worth budgeting for a
| slightly larger battery to allow a simpler overall
| design.
|
| Now if you say, had a mid-drive bike, or an internally
| geared hub, there are some complicated mechanical systems
| you can put in place to lock the freewheeling mechanisms
| in the gearing when you want to apply the brakes, but I
| haven't seen anyone design that yet.
| HPsquared wrote:
| Does cogging actually absorb energy though? (When
| averaged out)
| samatman wrote:
| It's certainly opinionated, I don't view 50-100 stops in
| ~30 miles as at all unreasonable.
|
| Something which is rarely done but easily could be for a
| bike is regenerating first into a couple supercapacitors,
| which are 99% efficient and fill and discharge as fast as
| you can push current. They don't have the capacity to be
| as useful in cars, for a bike they can also provide a
| nice kick to overcome starting torque. The downside is
| it's another two drink can's worth of volume to add
| somewhere on the bike.
| KennyBlanken wrote:
| Regeneration on a bicycle is only possible on hub motors,
| which usually have a planetary gearset to have acceptable
| low-end torque, and that gearset has significant drag.
|
| Mid-drive bicycles are able to leverage the freewheel,
| and thus have very high coasting efficiency.
|
| You don't really seem to know much about this. It's odd
| that you seem to have formed strong opinions on said
| subject.
|
| There is fierce competition in the industry for
| efficiency/range/price...not really sure why you think
| you can just casually stroll in and go "well DUH, folks,
| just do..."
| nradov wrote:
| I doubt it. Due to weight balance, most of the braking force
| is on the front wheel. This system only drives the rear
| wheel. Any regeneration gains would be minimal.
| HPsquared wrote:
| That only comes into play under hard braking. In most cases
| (gentle deceleration) there isn't much weight transfer: the
| rear wheel is fine for light deceleration.
| wiredfool wrote:
| It would be awesome for replacing the drag brake on a
| tandem for controlling speed on long descents.
|
| This is a niche in a niche though.
| a4isms wrote:
| I had a drum brake on my tandem for this very purpose. It
| wasn't even hooked up to a brake lever, it was wired to
| an old three-speed shift lever so you could set the
| amount of drag between none, some, and more.
| Tostino wrote:
| Not at all true, I built a dual suspension bike with a
| direct drive hub in the rear. I have it setup to regen, and
| I can use that to stop without touching my mechanical
| brakes for 95% of my riding. You generally only recover
| 5-10% over the course of a ride, but I am in FL with no
| hills, your results may vary!
| aidenn0 wrote:
| The controller on my e-bike indicates ~120 watts of regen
| from the rear-wheel. I'm pretty sure that's limited to
| increase life of the battery; there's plenty more available
| under heavy breaking.
| botswana99 wrote:
| Northern climate bike commuter here. I am getting tired of
| commuting in the snow and rain. I want a 'winter bike' that is
| fully enclosed, allows me to use my bike lane to work, and get my
| exercise without being covered in sleet, rain, or snow when I get
| home.
|
| When I was younger, the machismo of winter/rain commuting was a
| fun brag at parties. Now, when I look out the window after a long
| day at work. I want my exercise miles minus the macho.
|
| This could help me get that winter bike.
| asdff wrote:
| The enclosure is a lot of mass. Easier to get the same
| sheltering effect with better rain/snow clothing that you can
| just strip off and shove in a pannier or something.
| masklinn wrote:
| > The enclosure is a lot of mass.
|
| It's also a lot of sail surface.
| wolverine876 wrote:
| Isn't it more aerodynamic than a human on a bicycle?
| geocrasher wrote:
| No, not really. Not at the speeds most cyclists,
| especially commuters, travel at. You gain quite a lot
| more by going recumbent when it comes to drag. In fact, a
| recumbent bike, for the same effort, is a _lot_ faster.
| Putting a fairing on one of those is another story.
| Epa095 wrote:
| Sounds like podbike https://www.podbike.com/
| aidenn0 wrote:
| You can look up velomobiles. They are quite expensive though.
| Animats wrote:
| It's really an e-bike with a pedal powered generator. But it has
| a control system to create the illusion that the pedals are
| stiffly connected to the wheels.
|
| The e-bike people try too hard to pretend they're not building
| light-duty motorcycles. This seems to be changing. The wheels are
| getting smaller and stronger, and the center of gravity is going
| down.
| sandgiant wrote:
| > The Free Drive system works by converting the rider's pedaling
| power into electrical energy via a small generator housed between
| the pedals. It then delivers this energy to the rear wheel (or
| wheels) via cables strung inside or outside the frame of the
| bike, rather than sending it mechanically through a chain or
| belt. Excess energy created by pedaling is fed back into the
| battery. The end result is a power system with fewer moving parts
| to complicate construction.
|
| https://www.theverge.com/2021/9/2/22653697/schaeffler-free-d...
| jskrablin wrote:
| So... a generator, an electric motor, few microcontrollers,
| bunch of sensors, a battery with it's own management circuits,
| wires, a bunch of code running on everything... is supposed to
| be "less complicated" than a chain and two (sometimes more)
| sprockets? Or did I misunderstand the press release?
| ZeroGravitas wrote:
| One comparison is to e-bikes.
|
| Which often have most of that and a chain too.
|
| But also, e-bikes can let you ditch gears, which add
| complication.
|
| But I think the main selling point is that you can seperate
| the sitting/cycling position from the driven wheel in
| interesting ways.
| jandrese wrote:
| The selling point might be to finally have an "automatic"
| bike. Standard derailleurs are basically like having a
| stick shift on a car. The rider has to be trained on how to
| use them and they will make errors like leaving the gear
| setting too high when going on an uphill and then being
| unable to downshift because they aren't turning the pedals
| fast enough due to the high gear ratio.
|
| This is literally just get on and start pedaling and the
| bike figures out the rest. It even makes e-bike controls
| super easy, since you can just set a speed and start
| pedaling and it will supply just enough juice to make up
| the difference.
|
| The obvious downside is that it's going to be less
| efficient than a chain drive, because nothing beats a chain
| drive. But if you basically get the benefits of an e-bike
| for free then the efficiency loss isn't a big deal for the
| rider.
| NowhereMan wrote:
| I am surprised automatic shifting technology doesn't
| exist. Wireless electronic shifters are readily available
| now, in addition to power meters. We have devices to
| shift and devices to tell us when to shift. All that is
| needed is to marry the two together.
| opwieurposiu wrote:
| It does exist, in the form of a CVT and controller
| invented by a company called NuVinci. I built a cruiser
| bike with the manual CVT version years ago. It worked but
| the hub was very heavy. If you were stopped in high gear
| and you pushed down on the pedal really hard to start
| going it would occasionally slip. Once you got going it
| was pleasant to use but don't expect to win any races.
|
| They must not have sold very many of them because
| Fallbrook-NuVinci went into chapeter 11 and enviolo
| bought the tech.
|
| https://enviolo.com/products/
| sorenbs wrote:
| The Vanmoof bikes have automatic shifters. I don't like
| them because they are unpredictable, and you feel the
| difference. It's jarring. The Cowboy is single speed,
| which works pretty well because of the motor. That's my
| preferred configuration. But at high speeds it does feel
| like I'm at a spinning class, and it sounds like this
| system could fix that.
| AnIdiotOnTheNet wrote:
| Lets be real, the selling point of this nonsense is that
| you can ride your electric motorcycle on a bike path and
| pretend it is a bike because it has pedals.
| jandrese wrote:
| Personally, I don't get the hate over people using
| e-bikes on bike trails. While I am still fully pedal
| powered I have no problem with other people using
| e-bikes. Especially if the alternative is for that person
| to drive somewhere in a car.
|
| Maybe in other areas people are doing 60kph on bike
| trails or something, but that's not what I see around me.
| They seem to top out around 20kph or so, which makes them
| basically just bikes as far as traffic flow is concerned.
| Sure they will zoom past you on the uphills, but who
| cares? It's not hurting me or anybody else.
| Toutouxc wrote:
| There are lots of overpowered e-bikes with chain + gears,
| where the power going through the pedals is maybe 5 % of
| total power, and the rest is electric. This doesn't
| change or bring anything new to the table.
| ZeroGravitas wrote:
| There's at least one existing hub drive ebike that uses
| this model.
|
| It has a single gear, you can spin the pedals backwards
| to engage full regen, but the secret is that its usually
| doing a little regen which it stores and uses to help on
| hills and when accelerating from a standstill.
| dhosek wrote:
| I don't know about you, but I pretty regularly have my chain
| derail on my bike (at least a few times per season). Then I
| end up with grease on my fingers as I fix it which can be a
| big inconvenience.
| Steltek wrote:
| 1. Check your limit screws. Park Tool has nice Youtube
| videos for adjusting these.
|
| 2. If it's the rear derailleur, it may be bent (especially
| if your limit screws from step 1 are maxed out). You need a
| derailleur alignment gauge (or just take it to a shop) to
| verify.
| xcskier56 wrote:
| If your chain isn't too badly fallen off, you can usually
| just shift in the opposite direction of where it fell off
| and the derailleur will usually get the chain back on
| without having to get your fingers greasy.
|
| Be careful when you do this so as to not apply too much
| power when you're trying to do this. If you're in a really
| high gear and it happens, you can get off, hold your rear
| tire off the ground and turn the pedals. Works 90% of the
| time unless you got your rear chain jammed between the
| cassette and the spoke.
|
| Edit: You can very often see this if you watch professional
| bike racing. When the mechanics change a rear tire it will
| almost always knock the chain off of the front chainring.
| They'll just shift into the proper direct (low if it's off
| the high side and high if it's off the low side) and then
| spin the cranks and the chain will come back on.
| throwawayboise wrote:
| Tuck a pair of nitrile gloves under the saddle or into your
| toolkit. No greasy fingers.
| KennyBlanken wrote:
| Not really a normal thing;tTake your bicycle to a bicycle
| shop for diagnosis and repair. It make take a follow-up
| visit. Sometimes issues around dropping chains can be a bit
| complex to diagnose.
| analog31 wrote:
| Been there. If you're riding a 1x drivetrain, a narrow-wide
| chainring will greatly reduce chain drops. A conventional
| chainring is designed for the chain to be thrown off
| easily, and the front derailer keeps it there. On a 1x
| system, the ring can be designed differently.
| jasonwatkinspdx wrote:
| Hey thanks for this. I realized one of my bikes has been
| built wrong since I got it 15 years ago due to this
| comment.
| ramesh31 wrote:
| Wait until your chain gets ransomware
| sidewndr46 wrote:
| It's really catastrophic when the drive chain's watchdog
| timer has to reset it because some function went awry.
| IshKebab wrote:
| If it bothers you that much the solution is a belt drive,
| which is still more efficient than a generator.
| asdff wrote:
| Not a normal thing. My chain never goes out. Only on janky
| beater bikes it did. To the bike shop you go.
| jandrese wrote:
| You need to get your derailleurs adjusted. I bike almost
| every day and it never happens to me, even when I do
| inadvisable hard shifts.
| potta_coffee wrote:
| I've gone entire seasons of hard mountain biking and
| touring without having my chain come off. I think your bike
| might need an adjustment or maybe you have a worn
| chainring.
| olyjohn wrote:
| Do you regularly run out of power on your chain powered
| bike though? I get the feeling this system requires a
| battery (it even mentions battery in the article), and most
| of the actual power comes from that. The question is, will
| the generator make enough power to get you moving if the
| battery is totally flat? I kinda feel like no, you'd have
| to sit there and pedal it just to charge it up, and then it
| would move you a few feet. Or you're going to be pedaling
| really fast, and moving nowhere.
| bryanlarsen wrote:
| They claim to be 5% less efficient than a chain. So with
| a dead battery, you'd be limited to a speed of 95% of
| what you could do on a normal bicycle. That's if you're
| already moving. If you were at a dead stop I imagine
| you'd need to pedal a few strokes to get enough charge to
| get enough torque to overcome the stiction.
| tln wrote:
| Where do they claim that efficiency? I'm pretty
| skeptical... Chain+Derailleurs can be 98% efficient IIRC
| Johnny555 wrote:
| It only happens once a season or less for me and is almost
| always due to adjustment problems. And 90% of the time I
| can get it back on without touching the chain by using the
| front or rear derailleur.
|
| If you're riding a single speed bike and the chain
| regularly derails, then that definitely sounds like a chain
| tension or alignment problem.
| sudosysgen wrote:
| Bike drivetrains can require a fair amount of maintenance.
| Also a normal chain derailler system requires at least four
| sprockets, two in the derailler, one in the wheel, and one in
| the bottom bracket. Anything less is likely to be less
| reliable.
|
| You can expect to change the chain every 5000km. In theory a
| fully electric drivetrain could last forever.
| asdff wrote:
| All I do is lube mine and its been a gem for years now.
| People preach that there is this whole maintenance regimen
| and you have to be this hobbiest watchmaker to deal with
| bike gear ratios and such and such, yet most bikes just sit
| in the garage with the lube that came on them from the
| factory and work fine. Go to a college and see all the 50
| year old 10 speeds lined up in the racks. If you have a 50
| year old piece of hardware in such high use that doesn't
| seem like its this unreliable untrusty system to me, quite
| the opposite. Especially compared to like anything else in
| transportation, like a car that might incur thousands in
| repairs over its life. How many 50 year old cars are parked
| at the college? How many cars are even over 25? Even a
| skateboard is less reliable; take a skateboard out in the
| rain and the bearings are fouled and the deck may even
| warp. You can even get bike tires that make flat tires
| practically obsolete short of hammering in a nail because
| they use kevlar like a bulletproof vest. Literally
| bulletproof tech.
| colordrops wrote:
| Your phone is way more complicated than your bike and the
| hardware probably fails less often.
| postalrat wrote:
| Phones tend to get pretty nice treatment compared to bikes.
| Bikes are constantly stepped on and rubbed against
| pavement.
|
| Because if something goes wrong with your phone you
| probably won't be able to fix it. Compared to a bike where
| most anything can be repaired.
| colordrops wrote:
| It's a single unit, you just replace it, like you would a
| broken gear. You can't fix a broken gear unless you weld
| it.
| rilezg wrote:
| Idk, if you tried to use your phone as a bike I bet it
| would fail pretty quickly.
| colordrops wrote:
| I don't get your argument. What I'm saying is that
| complexity isn't necessarily directly correlated to
| reliability.
| Steltek wrote:
| My phone doesn't sit out in the sun/rain/snow at a bike
| rack and doesn't have any substantial moving parts.
| colordrops wrote:
| I think I didn't articulate my point well. It's that
| complexity isn't a 1 to 1 mapping to reliability. There
| is plenty of complex equipment that fits your criteria.
| My pool pump is full of electronics, has moving parts,
| sits in inclement weather, and lasts for years. There is
| equipment that can sit near the combustion chamber of a
| rocket experiencing extreme g forces, pressure, and heat
| and survive. It can be engineered.
| asdff wrote:
| I've had my bike 10 years. How can the hardware fail on a
| bike? Throwing it off a cliff? Meanwhile, the laundry list
| of hardware issues I could list on my phone probably
| affects every component in the stack over my decade of
| owning various smartphones. Each dying due to some faulty
| hardware issue, such as the radio giving out and dropping
| calls or the jacks getting loose or various other issues.
| newsclues wrote:
| Far more complicated that a traditional bike. But compared to
| e-bikes, this avoids a lot of the complex mechanical bits.
|
| I've had this system in mind for years, I think for cargo
| bikes with long chains, this will be a clear winner.
| a4isms wrote:
| Have you seen a high-end bike? The gears have batteries,
| electric motors, microcontrollers, and sensors. You'll also
| find wireless power meters, GPS, and even radar sensors for
| traffic on a contemporary bike.
|
| You get the idea. At the leading edge, bicycles are already
| extremely complicated. If we're comparing this idea to a
| bicycle from 2002, it's complicated. But I'm not sure that
| it's that complicated compared to the kind of bike you'd find
| in the roof rack of an Audi S4 Wagon :-)
| Steltek wrote:
| You're describing a high-end e-bike, which is basically an
| e-motorcycle with less regulation.
|
| A high-end regular-bike has electronic shifting and a power
| meter and that's about it. And you're talking many
| thousands of dollars worth of road bike. It's like seeing a
| Ferrari or a Lambo rolling down city streets. They exist
| but they're rare.
| Arainach wrote:
| Not necessarily. Shimano Di2 electronic shifting was
| introduced all the way back in 2001 and has been among
| the standards for high-end road bikes for many years now.
| It has all of those components. The electric motor
| doesn't have to drive the wheel.
| [deleted]
| a4isms wrote:
| Yes, but we're discussing technology that will also be
| rare. It's not like these chainless electric drive
| systems will appear on big-box sporting goods store
| bicycles, so why compare it to a mass-market affordable
| bike's technology?
|
| I think it's reasonable to compare a leading edge
| technology to a leading-edge existing product. Otherwise,
| it's like it's 2007 and we're complaining that this
| newfangled iPhone thngie can run out of battery in a day,
| while my POTS telephone works even in a blackout.
|
| Yes, true, but apples, oranges.
| Johnny555 wrote:
| I've seen them, even rode some bikes with electric
| shifters, but still don't want the complexity. One of my
| bikes is over 20 years old with the same Ultegra shifters,
| I haven't done any maintenance other than lubing once a
| season and they still work fine. I'd be surprised if the
| battery on electric shifters lasts that long.
| ashika wrote:
| pedal by wire
| kazinator wrote:
| No different from how most diesel trains work.
| KennyBlanken wrote:
| Totally different application/need though. Locomotives need
| to generate enormous amounts of force, for long periods of
| time, regardless of speed. Often at zero speed.
|
| That capability is much more important than the efficiency
| loss of the generator/motor powertrain.
|
| Such capability is not necessary on a bicycle, where
| efficiency is extremely important.
| uoaei wrote:
| Bikes handle much differently from diesel trains. This may
| work for some but I can see it occupying some kind of
| uncanny valley in the riders' psyche for a while.
| kazinator wrote:
| > _Bikes handle much differently from diesel trains._
|
| So, like, no nudging the right handlebar forward to turn
| right? Bummer!
| Fatnino wrote:
| You ever ride in one of those bar on wheels things you
| find in touristy places?
|
| It's got "barstools" along both sides and the
| passengers/revelers are supposed to turn the pedals under
| their seats while the bartender/driver steers.
|
| In reality, the pedaling charges the battery somewhat but
| the vast majority of the battery power comes from being
| plugged in at a charger before the ride. You can't
| actually rely on a bunch of drunk sods to keep it moving.
| lm28469 wrote:
| > Networked, flexible, sustainable, and environmentally friendly
|
| Adding batteries, more waste and breaking points is now
| "environmentally friendly" because "electricity"
| infecto wrote:
| Electric is generally a lot better than driving a scooter with
| an ice around.
| lm28469 wrote:
| But a "dumb" bike is miles better than an electric one in
| term of ecology.
|
| Replacing a ICE scooter is an electric bike is positive,
| replacing a regular bike with an electric one is a net
| negative. The argument only works if it replaces a more
| polluting option. Just like a Tesla can be a net negative
| depending on what it replaces
| samatman wrote:
| It depends on how you do your accounting. The electric bike
| is more efficient than the pushbike, just as the pushbike +
| human is more efficient than the pushbike alone.
|
| The carbon cost of a joule of food is higher than a joule
| of electricity, and joules are what get you where you're
| going.
|
| You can make a case that it's nice exercise you needed
| anyway; I like bikes as well. But the claim you're making
| isn't obviously correct and I would say it's more false
| than true.
| Tostino wrote:
| It also doesn't account for reduced car use due to having
| a more convenient mode of transportation than a standard
| pushbike.
| emerged wrote:
| Dave_Rosenthal wrote:
| I wonder how good they can make the feel without a direct
| connection to the road?
|
| For example, as you stand on a bike stopped at an intersection
| you have your foot resting on the petal, ready to take off. As
| you launch, you put a lot of force on that petal and rely on the
| feeling of connection to the ground to get going.
|
| This motor is going to have to hold that force statically and
| have a control system with sufficient power and bandwidth to
| emulate the familiar feeling of the ground. Not impossible I
| guess, but I wonder how well it works.
|
| Regarding efficiency, I think this is a smaller issue than it
| seems. Let's say a chain is 95% efficient and their system is 85%
| efficient (they claim 5% less efficient than a chain, apparently,
| but I'm sure that's a stretch). Most energy cycling, if not
| grinding up a steep hill, is dumped into air resistance. But
| speed only goes up with the cube root of power with regard to air
| resistance. This means (given the hypothetical numbers above)
| that you'd go 3.8% faster with a physical chain (or 1.7% if you
| believe their loss numbers). That difference is not perceptible
| on a bike and not an issue for 'getting around' use cases.
| makeitdouble wrote:
| > Regarding efficiency
|
| Air resistance is the main factor only if you're not actively
| stopping/restarting/braking as needed. In urban or semi-urban
| courses adjusting speed and stopping at red lights is par for
| the course.
|
| Also efficiency is really about effort. 95% is low for a bike,
| but even taking a 10% difference compared to the chainless one:
| for the effort you'd put to ride 10km with a chain, you'll only
| be around 9km chainless.
|
| As you say it might not matter if you're only going for
| groceries at 1 or 2km of your home. That's a different story if
| you use it to commute or plan on longer trips (now it could be
| seen as a handicap to get more exercise depending on the target
| customer)
| hgomersall wrote:
| People merrily put up with inefficient bikes for all sorts of
| reasons. If the only objective was to get between two points
| with minimal energy expenditure, everyone would be riding
| road bikes. Clearly other factors come into play.
| jasonwatkinspdx wrote:
| I have a track bike that's light as a feather, a cyclocross
| bike rigged with single rear derailed that's barely
| heavier, and a dutch style city bike that weighs like 4x
| the track bike. Guess which one gets ridden the most?
| barrkel wrote:
| I don't know. Which do you put your toddler on when you
| need to go shopping?
| aww_dang wrote:
| Extra weight from the batteries and electronics could be a
| bigger efficiency issue.
|
| Durability would be my bigger concern.
|
| Perhaps this would be a good fit for something like an
| electrified velomobile.
| sudosysgen wrote:
| I think it could in theory be more reliable and require
| less maintenance than a traditional drivetrain, but it's
| definitely going to be 7-10% less efficient than a good
| chain system.
| wolverine876 wrote:
| > This motor is going to have to hold that force statically and
| have a control system with sufficient power and bandwidth to
| emulate the familiar feeling of the ground.
|
| I understand that consumers will demand it, but ignoring that -
| what if they didn't simulate that resistance? Is there a
| functional need for it? What would it feel like? It's hard to
| imagine.
| analog31 wrote:
| It's interesting that after 140 years, the behavior of a chain
| drive safety bicycle with pneumatic tires is still the gold
| standard. Virtually everything that's noticeably better on my
| bike is related to the materials used. Although, variable speed
| gearing was a nice invention, but still, 100+ years old.
| hyperbovine wrote:
| Same thing with spoked wheels. The same design we use today
| would instantly be recognizable to someone from 150 years
| ago. (e.g. https://www.thehistorypress.co.uk/articles/from-
| discomfort-t...)
| thghtihadanacct wrote:
| I imagine spoked wheels would be recognizable by ancient
| chariot riders even.
| wolverine876 wrote:
| They wouldn't recognize them if they looked closely.
| Chariots, I'm guessing, had radial spoked wheels - the
| spokes are radiuses from the hub to the rim. Those were
| tried in early bicycles but didn't stand up well to
| usage. That led to two innovations in the late 1860s -
| mid-1870s that persist today:
|
| * Tension method of spoking: Invented by Eugene Meyer in
| Paris in 1869.
|
| * Tangential spokes: If you look closely at bicycles, the
| spokes are tangential to the hub, not radial. The
| tangent-tension combination (and maybe tangential spokes
| independently) were patented by James Starley in 1874.
| The "spokes are placed so as to be tangential to the hub
| in both the forward and the backward direction, thus
| forming a series of triangles that brace the wheel
| against torque during either acceleration or braking."
| [0]
|
| The improved spokes were introduced before chains and
| gears, allowing larger wheels. Larger wheels served as a
| subsitute for gearing, increasing the ratio between
| linear distance traveled and one rotation of a pedal, and
| thus the big-wheeled 'penny-farthing' or 'ordinary'
| bicycles were born.
|
| However, knowing the history, I haven't yet grasped the
| mechanics of how tension and tangents benefitted wheels,
| beyond general concepts. Does anyone know a good
| technical source (not Wikipedia)?
|
| [0] "Bicycle Technology" by SS Wilson (Stewart Wilson,
| afaik) in Scientific American (March 1973)
| lkbm wrote:
| True. One difference is that bicycle week spokes are
| tension-based, whereas I assume chariot wheel spokes were
| mostly about resisting compression.
| sudosysgen wrote:
| Indeed, the chain+derailleur system is incredibly
| lightweight, efficient, simple, and also fairly reliable.
| It's one of the most elegant solutions in mechanical
| engineering, imo.
| aidenn0 wrote:
| I find the chain+derailleur system to be less reliable than
| drive-shafts, but it's trivially repairable for a 10 year
| old with no tools, which is a huge win.
| brnaftr361 wrote:
| I disagree, I find chain and derailleurs to be annoying and
| unreliable in the worst way. I'll grant them their crown of
| efficiency, but I hope to see more refined CVTs. I
| currently have a bike with a NuVinci and I strongly prefer
| the way it functions over the clunky must-be-pedalling
| shifts of a derailleur. As an added benefit the system is
| contained, presumably hardening it against damage and
| reducing maintenance.
| asdff wrote:
| How do you find it unreliable? I put a couple thousand
| miles on mine a year and it sits outside. Occasionally it
| gets hit with wd40 then lube and a rag. That's all I do
| with this thing. I don't get all the complaints from
| people on the fiddling with derailleurs. I've never had
| to fiddle despite years of riding. Just some shimano
| components mostly 105 and ultegra but nothing special or
| too new. I'm still riding 2x8 actually. Maybe the fewer
| rear gears leads to fewer issues with alignment? I do
| find that I can shift into any of the rear cogs easily
| with either front cogs, very permissive groupset to being
| in the wrong gear at the wrong time too and sloppily
| finding another one (a lot of chaos sharing the road).
| Maybe I'm just not attuned enough to feel when the
| gearing is going out though.
| brnaftr361 wrote:
| Maybe I've just had bad luck, but two of the bikes I've
| had have come apart. The derailleur gets misaligned for
| whatever reason. One of them I had to take to a shop
| because despite extensive experiment I could not get it
| to properly align, and I don't know that they did either.
| The other was perhaps just old - an '80's era steel frame
| road bike from a Sears catalogue I donated to a repair
| shop, and it eventually got exploded for parts. I suspect
| the third would've succumbed to the same fate. It may
| just be me mishandling them, but if they can't handle
| this style they're not fit to ride. :cool:
|
| Also I hate dropping gears in the middle of an
| intersection.
| thghtihadanacct wrote:
| I think the key is matching up the right parts. I ride
| with a 1x11 mid grade set up that was made for each other
| and after dialing it in I have no issues either.
| potta_coffee wrote:
| I have 30 year old derailleurs with thousands of miles on
| them that are still going strong. I don't really
| understand the reliability complaint here.
| redprince wrote:
| I have left this behind for a Rohloff Speedhub 500/14 and
| I'm not looking back. The chain runs inside a Hebie
| Chainglider protected from the elements and is lubricated
| with a nice mineral oil. I can run this setup without any
| maintenance whatsoever for 2000km in every weather. The
| Rohloff itself will likely outlive me, provided it gets its
| oil change every 5000 km or so.
|
| I do utility cycling and long distance tour cycling.
| scoofy wrote:
| Ehh... not entirely true. It's the "gold standard" because of
| cost and (lack of) need. It's an elegant solution for non-
| functional cycling.
|
| Band-drive systems with internal hubs are superior for
| commuters who need reliability over anything else.
|
| Tubeless tires are now the standard for riding on irregular
| terrain.
|
| Disc-brakes are not the standard for hilly areas or people
| who ride at high speeds.
|
| Meanwhile, single chain-drive fixed/free gear bikes are still
| perfectly serviceable for most use cases (even if you need to
| select from a few different cog sizes to fit your area).
|
| The reason why "chain drive and pneumatic tires are the gold
| standard" is that most people don't ride bikes. If people
| did, you'd see much, much more variation in technology on the
| street, as they would be used for functional purposes, rather
| than recreational purposes.
| wolverine876 wrote:
| Some places have lots of functional riders, such as in
| northern Europe, and AFAIK they mostly use the gold
| standard.
| analog31 wrote:
| It can work both ways. If there are already lots of
| functional riders, they they probably have lots of
| functional bikes which means: They're confident about
| getting reliable use out of existing technology and are
| less likely to see new components as a silver bullet. In
| my case, none of the new developments are exciting enough
| to motivate me to replace my bikes, which work just fine.
|
| Off road cycling is its own beast, with the development
| of specialized bikes for that use, and also the design of
| trails that challenge both your skill and your
| technology. But the old footpath through the woods, or
| gravel road, is still the same as it ever was, and a
| regular bike handles it just fine.
|
| In the US, there's a perpetual effort by the bike
| companies to get people out riding, when everybody's
| already got a nearly brand new bike hanging in the
| garage. They want to sell new bikes, so of course the
| silver bullet is new technology. I think the rapid
| adoption of e-bikes shows that the real barrier was not
| the detailed performance of particular components, but
| physical effort. Who knew?
| wolverine876 wrote:
| > I think the rapid adoption of e-bikes shows that the
| real barrier was not the detailed performance of
| particular components, but physical effort. Who knew?
|
| Is there data on this rapid adoption? I'm not seeing it.
| It's hard to believe riding a bike is so much effort, but
| who knows?
| bryanlarsen wrote:
| A chain is 95% efficient in theory, but in practice they are
| usually a lot less.
| sudosysgen wrote:
| In theory a chain can be up to 99% efficient. In practice, a
| clean modern chain can easily hit 95%. Chains are by far the
| most efficient drivetrain.
| asdff wrote:
| How do belt drives stack up? I see more ebikes going belt
| drive which makes me think theres some efficiency gain
| there or at least its able to handle more torque perhaps.
| masklinn wrote:
| ebikes go belt drive for ease of maintenance and
| replacement, not for efficiency (they care much less
| since the motor compensates).
|
| The elasticity of the belt could also be an advantage if
| the engine is at the pedals (rather than in the hub), as
| it would allow for a less smooth engine programming,
| using the belt's elasticity to absorb some of the
| harshness.
| bryanlarsen wrote:
| Belt drives are less efficient than a well maintained
| chain but more efficient than a poorly maintained chain.
| E-bikes are less concerned about maximal efficiency and
| more concerned about ease of use. Belt drives don't need
| cleaning and greasing like chains do.
| Johnny555 wrote:
| I don't think they are going for road feel:
|
| _The central component of the Free Drive system is the
| Schaeffler generator, which sets the constant resistance on the
| pedal while simultaneously absorbing the rider 's pedaling
| power_
|
| So I think with this bike when you take off from a stop, you
| just squeeze the throttle or whatever controller it has and
| take off using battery power.
|
| On the other hand, you can pedal at your most efficient
| cadence/force all day long without regard to terrain.
| tecleandor wrote:
| > So I think with this bike when you take off from a stop,
| you just squeeze the throttle or whatever controller it has
| and take off using battery power.
|
| As they are German, I think that's not the case (if they want
| to be classified as an eBike). To be classified as an eBike
| it needs to work in "pedal assistance" mode. That is, you
| can't have a throttle/button/whatever, the engine only starts
| if you are pedaling.
| Johnny555 wrote:
| Ok, then you start pedaling, but since they specifically
| say it provides constant resistance, it's safe to say that
| they are not emulating road feel.
| MengerSponge wrote:
| Having kick-started a bike uphill from many stop-signs,
| let me say that road feel is 100% overrated
| stefs wrote:
| i doubt it's designed for classic single-person e-bikes;
| there's one picture at the bottom of a cargo-bike with a
| person-sized transport box. i think this system is for
| small inner-city utility vehicles for delivery services and
| craftsmen (transport of a limited set of tools and
| material).
|
| the low overhead of bikes (registration etc.) isn't
| necessarily a problem for a company's motor pool. iirc it
| might very well be possible to ride those on bike paths -
| even if they need a moped registration plate - as long as
| the maximum power and speed is limited.
|
| in austria, small electric numberplate-less mopeds
| (scooters) with a 25km/h speed limit and no pedal assist
| are legal, no idea about germany tho.
| sorenbs wrote:
| European ebikes are also limited to a 250w motor. They must
| need much more to make this system work, so probably can't
| be classified that way.
| barrkel wrote:
| 25kph eBikes per EU regulations are allowed a throttle if
| it cuts out at 6kph, IIRC. Just for starting, in other
| words.
| SigmundA wrote:
| >Regarding efficiency, I think this is a smaller issue than it
| seems. Let's say a chain is 95% efficient and their system is
| 85% efficient (they claim 5% less efficient than a chain,
| apparently, but I'm sure that's a stretch).
|
| Would be interesting to see proof of their efficiency claims,
| having looked into this before series hybrid drivetrains are in
| the 80% efficiency range, you have generator->charge
| controller->motor controller->motor losses.
|
| There are no production series hybrids I am of aware of in
| automobiles, all hybrid seem to have a parallel component
| connecting engine to wheels at highways speeds because its much
| more efficient.
|
| Trains and large boats do diesel electric drivetrains but its
| not for running efficiency but other factors like traction
| /throttle control and power routing.
|
| Its very difficult to out perform a mechanical drivetrain in
| both weight and efficiency if your power source is mechanical
| (ICE / human body).
| ZeroGravitas wrote:
| BMW i3 has an optional range extender Which is a motorcycle
| engine that only generates power.
|
| Nissan e-power cars are hybrids that you can't plug in, but
| all power is generated by the ICE and then fed to the
| electric motor before it gets to the wheels.
| SigmundA wrote:
| I guess I think the i3 doesn't count since its only a 34hp
| engine so it can't really power the car in normal driving
| (without sitting and letting the battery recharge for a
| while) its just a range extender but yes it is technically
| a series hybrid. It also has pretty poor efficiency using
| gas (31 mpg combined)
|
| The Nissan e-power is interesting, having not dug deep into
| it before, it looked like it obviously had a engine to
| wheel connection through the transfer case. Thought they
| where pulling a Chevy and claiming series hybrid when
| actually parallel, but just digging deeper its very strange
| the engine output and drive gear are separated only by MM
| as though they where leaving the design open to a
| mechanical connection. Never the less its difficult to get
| highway MPG numbers on it which is why most hybrids have a
| mechanical connection. Electric is more efficient stop and
| go city driving while steady state highway mechanical
| transfer is more efficient. Would like to see power loss
| numbers and highway mpg, my guess is on the highway the
| E-Power would lose out to a Prius.
| barrkel wrote:
| 25hp is enough to propel a very non-aerodynamic scooter
| (it's about what most 250cc models produce), with the
| rider sitting up in the wind blast, at a continuous
| 130kph. An car can be more efficient at cutting through
| the air.
|
| What it's not enough for is much acceleration at those
| speeds. But a battery buffer would help hugely, as long
| as you aren't driving very sportily for an extended
| period of time.
| jasonwatkinspdx wrote:
| You are mistaken about the i3. Some friends had one and I
| joined them on several road trips. Driving it long
| distances is no different than any other car. You just
| stop and fill up the tank every few hours. The range
| extender pops on as needed to keep the battery from fully
| drawing down. It's important to remember it doesn't
| actually take that much horsepower to just keep a car
| putting along at reasonable speeds. Even economy engines
| are oversized compared to that due to the need for good
| low end torque in start/stop conditions. But a hybrid
| solves that the other way.
| SigmundA wrote:
| Although less of an issue than I thought there are
| driving conditions where it cannot maintain speed due to
| lack of power, it was a big enough issue for class action
| lawsuit to be filed over it dropping to 45mph on the
| highway:
|
| https://www.greencarreports.com/news/1105823_bmw-i3-rex-
| rang...
|
| And again my main point was on efficiency, I would hope
| you agree 31mpg combined is extremely poor for a 34hp
| engine when much larger engines get much better mileage
| and have no issues with providing power when needed
| without battery assistance.
|
| It doesn't need much hp to maintain highway speed
| (probably around 34hp on flat ground) which means the
| engine is running full throttle to do so, vs running in
| it most efficient range which is not where it puts out
| peak power.
|
| The e-power Nissan has a full size engine, but a small
| battery, although would be interesting to compare it
| drivetrains weight with a standard one, having both a
| electric motor and generator of equal size is typically
| much heavier than a transmission.
| smm11 wrote:
| I have a BMW diesel sedan, and have averaged 56 mpg over
| the past 14 months. Starting from a dead stop is nearly
| all the fuel consumption, like an Atlas rocket. On flat
| ground, the car gets 70-90 mpg, and if not driving like
| an idiot up small hills, it's in the 50s.
|
| My commute is very stop-go, otherwise I think the car
| would be in the upper-60s all the time. I've often
| wondered if there was a way to have an electric motor
| handle the movement of the car up to about 15 mph.
| skykooler wrote:
| > There are no production series hybrids I am of aware of in
| automobiles
|
| Would not the Chevy Volt count? The gasoline engine only
| serves as a generator, it is not mechanically connected to
| the wheels.
| wolrah wrote:
| > The gasoline engine only serves as a generator, it is not
| mechanically connected to the wheels.
|
| The Volt can operate in a series hybrid mode, but there is
| also a mechanical connection that is engaged at certain
| speeds where it's more efficient to just direct drive
| rather than double-convert the energy from the combustion
| engine.
| kevin_thibedeau wrote:
| > There are no production series hybrids I am of aware of in
| automobiles
|
| The Chevy Volt was the first production series hybrid.
| SigmundA wrote:
| Volts have a mechanical connection: https://www.gm-
| volt.com/threads/gen-2-volt-transmission-oper...
| throwawayboise wrote:
| Trains do it because they need to apply a lot of torque at
| zero speed to get moving. The only way to do that with a
| mechanical connection to a combustion engine is with a
| clutch, which would burn up from friction before the train
| got going.
|
| In theory a hydraulic pump would work, but I'm sure that
| electric motors are better for that usage, since that is what
| they use.
| jasonwatkinspdx wrote:
| There's also torque converters, which are a hydraulic
| mechanism. This is the basis of most (non sporting)
| automatic transmissions. Higher performance torque
| converters have a lock up mechanism that functions as a
| clutch making it rigid at high speeds. So you can kinda get
| both.
| masklinn wrote:
| > There's also torque converters, which are a hydraulic
| mechanism. This is the basis of most (non sporting)
| automatic transmissions.
|
| By virtue of being the dominant automatic transmission in
| the US, where automatic transmission is the overwhelming
| majority.
|
| In Europe, torque converters have never been much of a
| thing, historically because of the small engines (at the
| low end, and demand for control and responsiveness at the
| high end), and more recently for efficiency reasons.
|
| AT has been shooting up in popularity (in parts because
| gearings have been getting shorter which makes manual
| transmissions really annoying), but mostly on the back of
| DCTs, even at the low end e.g. these days it's pretty
| common to find a 6-speed DCT on a B-segment car, and
| C-segments getting 7 or 8-speed DCTs (AMTs sadly still
| survive at the lower end of AT, but I feel CVTs are
| eating their bacon, especially with progressive
| hybridation).
| SigmundA wrote:
| Modern lock-up torque converter transmissions have pretty
| much eliminated any efficiency gains from other designs,
| I believe everyone is moving to them even in Europe. I
| know here in the US many care from various manufacturer
| are coming with German designed ZF transmissions
| including the 9 speed in my Honda Pilot.
|
| https://www.autocar.co.uk/car-news/technology-news/under-
| ski...
|
| https://www.caranddriver.com/features/a23367341/automatic
| -tr...
| SigmundA wrote:
| There are hydraulic trains, they have poor running
| efficiency worse then electric. My understanding is in
| order to get a large train moving with steel on steel
| requires very precise traction control that lends it self
| to electric, while doing a mechanical coupling for cruise
| speed would be very complicated and expensive so they eat
| the efficiency loss there. They are also saving brake wear
| using the traction brakes which just run heat strips on the
| top of the train.
| Toutouxc wrote:
| > electric motors are better for that usage, since that is
| what they use
|
| Except those that actually use hydraulic couplings or
| torque converters, which is the cheaper and lighter
| solution compared to electric, albeit less efficient.
| frosted-flakes wrote:
| They also do it for simplicity (reliability and less
| maintenance). A that scale, a mechanical drivetrain to all
| those wheels would be much more complicated than electric
| motors and cables.
| graycat wrote:
| Classic fact from my old college E&M (electricity and magnetism)
| course:
|
| "A series wound electric motor has infinite torque at stall"
|
| Okay, the electric connection between the pedals and the drive
| wheel should act as essentially as a _perfect_ transmission, that
| is, with infinitely many gears (except for the 5% or whatever is
| lost in efficiency). And if the wheel motor is "series wound",
| then should have the "infinite torque" when starting from a dead
| stop. That infinite torque could be nice to have when going up a
| steep hill -- e.g., for the last 10 speed bike I had, the lowest
| gear was still not low enough to let me pedal up my steep
| driveway and, instead, I had to walk my bicycle up that hill.
|
| Also, for that bike, the highest gear was not high enough -- on
| the _course_ I was using, there was a long hill, and in the
| highest gear before I got to the top I was pedaling as fast as I
| could and wanted a still higher gear.
|
| Sooooo, for something better, if the _constant torque_ generator
| had a resistance adjustment, then just increase the resistance a
| little, let me pedal at the same RPM as before, and get up the
| hill faster; that is, I would be pedaling with my maximum power
| and the infinite gearing would move the bike at the maximum speed
| for that power, e.g., the power needed for the friction and air
| resistance for that maximum speed.
|
| Constant torque at the generator side and infinitely many gears
| connecting to the drive wheel -- NICE!
| Tostino wrote:
| I cannot see why anyone would prefer this for a bicycle that is
| at all shaped like a normal bike. An integrated mid-drive ebike
| is just all around much more efficient.
|
| Direct hub motors for large (bike size) diameter wheels frankly
| suck at this point in time. You need to have much more copper to
| efficiently drive the motor at the power levels required, because
| RPM is so much lower with hub motors. Not being able to use RPM
| to your advantage is such a huge efficiency hog at low speed
| acceleration, which is a lot of how people use ebikes.
|
| If this is using an internally geared hub, my point is moot;
| however that comes with it's own drawbacks. It's incredibly hard
| to get heat out of a geared hub motor efficiently. Your motor is
| encased inside the hub, with no direct connection for heat to
| escape, and you generally have way less copper available to heat
| soak.
|
| Mid drives get the advantage of mechanical gearing, and can be
| built in such a way to allow very little heat generation to begin
| with, but you also can easily cool something in the frame
| compared to a spinning hub.
| kazinator wrote:
| > I cannot see why anyone would prefer this for a bicycle that
| is at all shaped like a normal bike.
|
| There are already e-bikes out there with a design that puts a
| motor into the bottom bracket; so there are already frames for
| this.
|
| That's probably what is being targeted.
|
| In the absence of such frame designs existing already, this
| idea would be hard to pitch. The path already seems paved
| though.
|
| We have e-bikes with bottom bracket motors, which assist the
| pedals, and drive a chain. We also have bike wheel designs with
| a hub motor that can retrofit into ordinary bikes.
|
| This looks like it just combines the two: take a bike which has
| a bottom bracket motor, and replace the motor with a pure
| generator. Scrap the chain and sprockets, and just deliver
| electricity to a hub motor.
|
| Chains and sprockets get dirty and require cleaning, except in
| fully-closed systems that require a complicated transmission.
| Chains can slip and break. Chains wear out and require
| replacement, usually together with the rear sprockets. Front
| rings wear also; about once every three times you change a rear
| sprocket, you have to change the front rings which, for entry
| level bikes is usually most cheaply done by getting the entire
| crank set.
|
| Typically, a multi-speed rear cassette must be removed in order
| to replace a broken spoke, which is a PITA. This is because it
| is larger than the hub, and is right next to it, blocking
| access to the spoke entry holes on the drive side. You need
| chain whip to prevent the hub from turning, while you apply a
| wrench to a special lock ring tool, using a great deal of
| force. From the looks of most wheel builds with a hub motor, it
| looks like the spokes are easily accessible without removing
| any difficult part from the wheel: just get the wheel out of
| the bike.
|
| Internal gears alleviate some of the issues with chains.
| Without a derailleur system, chains can be encased to protect
| them from the elements. An electric transmission is going to be
| more efficient and quieter than internal gears, though, and
| require no maintenance.
| mauvehaus wrote:
| You make some good points, and I'd venture to guess that
| you're handy with a bike, but for the vast majority of people
| who use bikes, what you're saying about maintenance is
| totally irrelevant.
|
| I'm also handy with a bike, and I've spent some time
| volunteering fixing up used bikes for resale. Here's what I
| usually saw:
|
| > Chains wear out and require replacement, usually together
| with the rear sprockets. Front rings wear also; about once
| every three times you change a rear sprocket, you have to
| change the front rings which, for entry level bikes is
| usually most cheaply done by getting the entire crank set.
|
| This is true, but very, very few bikes ever get the kind of
| miles put on them to wear out a chain. If you ever wear out a
| chain, you're conservatively in the top 3% of cyclists by
| miles ridden. Mostly chains die a slow horrible death by
| being left outside all winter and turning entirely into a
| rusty immovable mess. If they're completely beyond saving,
| you cut them off with a hacksaw, put on a new one, check the
| cassette, and move in to the next neglected thing. I've never
| replaced a cassette other than on my own bike, no matter how
| nice or shabby the bike looked.
|
| In the extraordinarily unlikely case that somebody manages to
| wear out the chain on a cheap bike, they're almost certainly
| as well off just buying a new cheap bike. Everything on a
| cheap bike is crap, and by the time you've killed a chain,
| something else will need to be fixed. Unless the labor is
| free (mine was, that was the point), you're quickly into more
| money to polish a turd than to buy a new one.
|
| If by "entry level", you mean "inexpensive from an actual
| bike shop", then yeah, it might be worth replacing some
| drivetrain components. Even so, you'd be dealing with the
| unicorn rider who rides enough to wear out a chain, but also
| doesn't want to upgrade to a midrange bike.
|
| > Typically, a multi-speed rear cassette must be removed in
| order to replace a broken spoke, which is a PITA. This is
| because it is larger than the hub, and is right next to it,
| blocking access to the spoke entry holes on the drive side.
| You need chain whip to prevent the hub from turning...
|
| I've broken and replaced spokes. It's pretty rare, and it
| requires special tools. Most cyclists can't adjust a
| derailleur, and a surprisingly large number are incapable of
| fixing a flat.
|
| Everything you're saying is true, but for nearly everybody, a
| broken spoke is a job for a bike shop. The barrier for
| replacing a spoke for most people isn't having the tools,
| it's knowing how to use them, and specifically how to re-true
| the wheel. I don't mean getting it perfect on a stand, I mean
| getting it rideable using the brake pads for a reference.
|
| I know somebody who used to race competitively. He has a shop
| do all his maintenance because he's not even the slightest
| bit handy, and I can only assume it's not for the lack of
| opportunity to learn while he was riding competitively.
| kazinator wrote:
| Maintenance is not "totally irrelevant" to people who have
| someone else do it.
|
| > _This is true, but very, very few bikes ever get the kind
| of miles put on them to wear out a chain._
|
| I suspect that is changing with e-bikes which are used for
| actual daily commuting. People buy those things to ride
| them.
|
| In my experience, daily commuting of around 20 km on a non-
| powered ordinary bike all year round requires a yearly
| chain replacement. You can get away with a once per two
| years cassette job.
|
| Now these e-bikes have serious torque and power. You
| regularly see them keeping up with cars going 50 km/h or
| more, even uphill. Yet may use use ordinary drive trains,
| such as entry-level Shimano cassettes, derailleurs and
| rings. The power of the motor can easily be expected to
| trash these components way faster than a human power.
|
| > _In the extraordinarily unlikely case that somebody
| manages to wear out the chain on a cheap bike, they 're
| almost certainly as well off just buying a new cheap bike._
|
| This is false, because chains cost something like $15-$30.
| Cheap chains and drive sets are still found on entry-level
| real bikes that might go for $600-$800 or whatever. You're
| not going to replace an $800 bike because of the chain.
|
| It wouldn't make sense to replace even a $100 bike-shaped-
| object if all it needs is a $15 chain. There was a time
| when I rode crap bikes; I still maintained them, and
| replaced the chain.
|
| > _I 've broken and replaced spokes. It's pretty rare._
|
| During my daily cycling era when I didn't have a car for
| some 8 years, I fixed about 3 broken spokes per year.
| Almost always on the drive side of the rear wheel. So while
| rarer than a flat tire, it's not that rare.
|
| I had no time for bike shops. They are too far away and
| have stupid hours like not opening until 10:30 on a
| weekday, and being closed Sundays. They will keep your bike
| for at least a day, and charge some ridiculous amount to
| change a part that costs a dollar.
|
| Truing a wheel is not difficult (particularly lateral-only
| truing), and once you go to disc brakes, perfection is less
| important. The bike can even be ridden for a few days with
| a broken spoke: you just have to clip it off, because you
| don't want a broken spoke flailing around. It's not a great
| idea to ride a wheel with a broken spoke, but lets you
| schedule a good time to fix it, if you're busy
|
| What I'd pay a shop to do would be axial truing: fixing the
| eccentricity of the wheel's circle. I asume that if I tell
| a shop to true a wheel, they are only going to care about
| left-right wobble, which "anyone" can do.
| mrob wrote:
| >I fixed about 3 broken spokes per year. Almost always on
| the drive side of the rear wheel.
|
| This hints at one less obvious advantage of the drive
| system described in the article: no need for asymmetrical
| wheel dishing. Rear wheels for conventional derailleur
| systems have to be built asymmetrically[0]. This makes
| the wheel weaker than a symmetrical one, because the
| drive side spokes are under higher tension.
|
| I ride a hub gear bicycle with symmetrical wheels as my
| primary form of transport and I've never broken a spoke.
| Electric drive would allow the same wheel strength.
|
| [0] https://en.wikipedia.org/wiki/Bicycle_wheel#Dish
| mauvehaus wrote:
| Let me put it in programmer terms: you and I are like the
| 1% of browser users who open the developer tools. We
| exist, but to the larger bike industry the number of
| people like us rounds to zero.
|
| You also fall into one of the (as far as I can tell) two
| groups that skew heavily towards caring about end-user
| maintainability: hard-core transportation cyclists (you,
| and to a much lesser extent me), and people who bike tour
| (me as well, though not recently)
| Jemm wrote:
| Gonna make a guess that this is not meant to be used as a source
| of propulsion outside the e-bike ecosystem. To lllustrate, here
| in Toronto, e-bike must have pedals that can be used to actually
| move the bike. Electric assist must be "pedal assist" and not
| throttle based. My guess is that the Free Drive system is
| intended for that purpose.
| loonster wrote:
| An AWD bicycle would be pretty neat.
| throwawayboise wrote:
| AWD motorcycles have been done. They are useful in extreme off-
| road scenarios.
|
| http://www.christini.com/awd-technology/about-the-tech
| tux1968 wrote:
| Would be nice to have one of these pedal units installed on a
| footstool, so that I could charge my phone while watching a video
| on the couch.
| nradov wrote:
| I would like to have a bike with this drive system for doing
| structured training workouts outdoors. Cyclists and triathletes
| often do workouts involving multiple steps with a prescribed
| power output, for example 10 one minute intervals at 300 W with
| two minutes of recovery at 140 W plus 15 minutes of warm up and
| cool down at 170 W. It's simple to execute that workout on an
| indoor smart trainer in erg mode since it will dynamically adjust
| the resistance to hit the exact target power, but even with a
| game like Zwift indoor training is super boring. You can do the
| same workout outdoors on a real bike, but then you have to keep
| watching the power meter to stay in the target range which is
| distracting and somewhat of a safety hazard. So this system could
| offer the best of both worlds if the target power is externally
| controllable through ANT+. Of course that would probably be only
| a small niche market.
| Mildlypolite wrote:
| Hi, I remember that an app similar to what you are talking
| about were developed for the specialized evo ebikes. You could
| set a fixed power output and if you went higher the motor would
| come in to help you stay in the power You choose. Pretty cool.
| user32489318 wrote:
| I see your point, and I can see some application in group
| rides, social events with a less fit SO, but 1) in TT, or even
| in any regular bike climbing, holding constant power is an
| important skill to master. Try doing a 45min varying gradient
| climb at 5-15% below FTP. It is not only your legs, but also
| your brain anticipating the gear shifts. Give the Alpe du Zwift
| a try, turn ERG mode off, and you'll understand what I mean.
| Variance in the power output wears you down. (that's why we use
| Normalised Power numbers for fatigue). You've to train that,
| not by doing3min on-1min off intervals, but by riding on real
| tarmac. Also, after few thousands hours of training you don't
| need to look at your head unit to know if your power is
| constant or not. 2) Power is not the only bottleneck for riding
| 300W, 400W, 450W for 10min, that where the handling skills of
| your bike come in play. That one of the reasons why we do
| 'speed training', cycling behind a buddy on a scooter/car. To
| get used to the cadence, braking, steering, ... Imagine
| participating in a race, riding 50+km/h without any fast
| cornering/breaking experience, that's a hazard! 3) Imagine
| doing an all-out interval session on TT bike, in a full aero
| position, and getting passed by an elderly on e-bike. Everyone
| will think "that guy is a bit weird", won't they? 4) Max. power
| output of this motor is 250W, I believe this to be an EU
| regulation. That is 20% less power on the rear wheel than the
| FTP of an average amateur racer. There are also speed
| regulations in EU, 25-28 km/h. That's certainly the Strava
| numbers to show off! You can make it a motorcycle/scooter and
| remove these limits, but then you'll need to wear motorcycle
| helmet in many EU countries. Also, you are no longer allowed on
| the bicycle lanes. 5) People who are serious enough about their
| cycling are generally quite serious on the bike position. For
| example, the Q-factor is the distance between your shoe cleats.
| Favero released power meter pedals for Shimano SDP-SL cleats,
| but added 1cm to the q-factor, just look at the flame war it
| caused. 6) Most people train on their 'race-day' bike. Some
| have a spare 'bad weather' bike. Now, you want to train on an
| additional training bike, with a different geometry to the
| race-day bike? Or are you expecting to have a TT bike with this
| drive train + a race day TT-bike? TT-bike will run into 5-15k
| USD, I might like my hobby, but won't put extra 5-15k for this
| nice to have feature.
|
| I think 'niche market' is an underestimation, since there are
| already assisted racing/MTB bikes (limited to 28km/h), just
| slap power meter pedals on and you're ready to go.
| mrfusion wrote:
| Could this let us put a kill switch in bikes? Maybe enforce
| exclusion zones?
| VectorLock wrote:
| Is anybody selling these in a complete bike yet?
| marcodiego wrote:
| > The regenerative solution is a serial hybrid drive that
| converts the mechanical energy generated during pedaling into
| electric energy, which in turn is converted back into mechanical
| energy in the wheel hub motor.
|
| How much efficiency is lost compared to a direct mechanical
| system?
| m463 wrote:
| That's what I wonder too. Honestly, the efficiency of a chain
| drive system is really high. (however, it should match your
| body's efficiency - 90 is supposed to be an excellent cadence
| for cardio, and is good for the knees)
|
| wikipedia says up to 99%:
|
| _Mechanical efficiency_
|
| _From a mechanical viewpoint, up to 99% of the energy
| delivered by the rider into the pedals is transmitted to the
| wheels (clean, lubricated new chain at 400 W), although the use
| of gearing mechanisms reduces this by 1-7% (clean, well-
| lubricated derailleurs), 4-12% (chain with 3-speed hubs), or
| 10-20% (shaft drive with 3-speed hubs). The higher efficiencies
| in each range are achieved at higher power levels and in direct
| drive (hub gears) or with large driven cogs (derailleurs)._
|
| https://en.wikipedia.org/wiki/Bicycle_performance
| bikemike026 wrote:
| I live on a bike. It's my primary mode of transportation. This
| could be a very interesting choice. Getting around is not about
| speed. It's about ease. If this system can get people around more
| easily then it's worth pursuing.
|
| There are bicycles with chains, belt drives, pedal assist
| electric, and throttle electric. I would be interested to know if
| this system could work without plugging in, get me up a steep
| climb, and do it cheaply. I use chain drives but belt seems to be
| the winner at the moment.
| yohannparis wrote:
| I like innovation like this, but I will never buy one. A chain or
| belt will always work when the battery is dead. Or something went
| wrong. I need a fail-safe mechanism, and this idea does not offer
| one.
| a4isms wrote:
| An escalator can never break: it can only become stairs. You
| should never see an Escalator Temporarily Out Of Order sign,
| just "Escalator Temporarily Stairs. Sorry for your
| convenience."
|
| --Mitch Hedberg
| ryukafalz wrote:
| This is a funny quote, but for those who don't know it's also
| wrong. Escalators can indeed break, and violently:
| https://gizmodo.com/catastrophic-escalator-failure-in-
| rome-s...
| Toutouxc wrote:
| There's also the fact that an escalator makes for some
| terrible stairs -- the steps are much taller then what
| would be comfortable (and allowed, AFAIK) for stairs.
| bryanlarsen wrote:
| This is a generator, a dead battery is not a problem. Nothing
| in this setup is less likely to break than your chain or a
| derailleur -- I've had those happen to me a couple of times
| each.
| missblit wrote:
| It is however a lot easier to cart around a chain tool and a
| replacement chain than a replacement generator.
| bryanlarsen wrote:
| Which I do on longer rides, but they only seem to break on
| casual rides when I don't have them.
|
| But I've also broken frames and taco'd wheels. Should I
| bring spares for those?
|
| That generator can probably do a million miles.
| soared wrote:
| You must be putting your bikes through hell and never
| maintaining them. There are no instances where a chain
| should break if properly maintained and replaced at the
| end of its life.
| bryanlarsen wrote:
| It's happened twice. Once was on a really old chain. The
| other I'm not as sure. I'm a heavy guy. If I use my
| weight I can put a lot of torque on the pedal.
| nradov wrote:
| Conventional mechanical drive trains are very efficient, but
| those with multiple gears can be fragile with exposed moving
| parts subject to damage and misalignment. Most of us who ride a
| lot have experienced broken shifter cables, bent derailleur
| hangers, etc. Hardly fail safe. A well engineered electric
| drive system could potentially be more robust and reliable, but
| obviously more expensive and less efficient.
| liftm wrote:
| I cannot count the number of times I trashed my gears. And the
| fail-safe is walking. (I assume you're using a fixie?)
| ptmcc wrote:
| Something is very wrong with your bike if you are frequently
| "trashing" your gears. I've been riding bikes for 30 years
| and have never had to walk due to drivetrain failure.
|
| As long as the drivetrain is set up well initially, a
| traditional bike will go many thousands of miles on pretty
| minimal maintenance.
| KennyBlanken wrote:
| Single speed transportation bicycles are extremely common
| where there aren't significant hills. Internal gear hubs have
| regained significant popularity, too - ranging from 2 to 11
| speeds.
|
| Not sure why you're "trashing your gears" so regularly. Older
| cassettes/chains didn't like being shifted under significant
| power but anything made in the last 20+ years by SRAM or
| Shimano or Campagnolo really shouldn't have a problem being
| shifted while full-on sprinting.
| sandworm101 wrote:
| Take away the chain and you are on the slippery slope to electric
| motorcycle. This thing is clearly meant for an electric moped. Up
| the batter/motor power a little and the human input becomes
| irrelevant. You are then driving an electric motorcycle with some
| pedals for topping up the battery. Absent the chain-to-pedal
| drive, the only difference become e-bike and e-motorcycle is some
| arbitrary line about battery/motor capacity.
| analog31 wrote:
| Some of the technology choices are driven by: 1) Regulatory
| distinctions between bikes and motorcycles (and scooters,
| etc.), how they are licensed, where they can be used. 2)
| Providing the experience of low intensity exercise.
|
| Don't remember where I read it, but e-bikes are becoming
| prevalent enough in some parts of Europe, that there is a bit
| of a regulatory backlash going on, for instance requiring a
| bike to get at least 1/2 of its power from the rider.
| Steltek wrote:
| e-bikes around here (Boston) seem to be mostly motorcycles
| with vestigal pedals. If the rider stopped pedaling, I'm not
| sure there would be any visible change in vehicle behavior. I
| may not like it but I prefer it to having more cars on the
| road.
| dropofwill wrote:
| There are plenty of people with throttle-less electric
| hybrids/mountain bikes as well, but they blend in with the
| other cyclists (until the road tips up hill).
| analog31 wrote:
| In my locale, they are more like small motorcycles without
| brakes.
|
| Actually, most of the e-cyclists are quite well behaved,
| but there does seem to be a tendency among the beginners to
| maneuver through things at speed, that a conventional
| cyclist would slow down for. My guess is they haven't
| developed a sense for how far ahead of themselves they
| actually need to be paying attention.
|
| But also, I admit that there's a certain bias here. There
| are fast and slow cyclists, and those who are polite or
| jerks. You don't notice the polite cyclists at all. You
| don't notice the slow jerks, because they're behind you.
| You only notice the fast jerks, on either electric or
| conventional bikes. So there's a bias towards thinking that
| fast riders are jerks.
| Steltek wrote:
| Eh, the slow riders are jerks too :). At a red light,
| they'll cut the line and blow through the intersection.
| Then the light turns green and you overtake them until
| the next red light. Rinse and repeat until you get to
| work/home.
| sandworm101 wrote:
| >> without brakes
|
| That is key. Brakes are largely unregulated on bicycles,
| at beyond laws saying that they need to have them.
| Standards for braking power and/or stopping distance
| would be fought tooth and nail. All those ultra-efficient
| bikes on slim tires wouldn't be possible if someone set
| minimum stopping distances.
| analog31 wrote:
| Actually I was being sarcastic, always a bad idea on web
| forums, sorry. "Without brakes" meant that people don't
| slow down when they should. And to be charitable, I think
| it has to do with people learning what kind of
| situational awareness and reaction time are needed.
|
| The US CPSC does regulate bike brakes. The latest
| generation of e-bikes actually have quite effective
| brakes, nearly entirely hydraulic discs.
|
| https://www.ecfr.gov/current/title-16/chapter-
| II/subchapter-...
| sandworm101 wrote:
| Those are regs for sold bikes, not bikes on the street.
| It doesn't cover customized/user-modified bikes which are
| the vast majority of commuters these days.
|
| There was a man in the UK recently charged with the death
| of a pedestrian. He was on a fixed-gear bike without
| front brakes. Causing death during illegal activity means
| homicide charges in many jurisdictions.
| analog31 wrote:
| Aha. My state prohibits _operating_ a bike without a
| brake, though the regulation is light on specifics. I
| read about that incident too.
| pmyteh wrote:
| It's interesting, because this exact transition (bike+motor
| assist -> motorbike) has been seen before. In Britain we
| had the category of 'moped', complete with vestigial
| pedals, before they were subsumed into the small motorbikes
| (limit: 50cc engine).
|
| The difference is that now the motor is electric, not a
| small petrol engine. Will be interesting to see if we end
| up treating them (again) as small motorbikes, or as bikes
| with assist (so no compulsory helmet, insurance, or
| registration).
|
| Edit: around here (Liverpool) I see them styled both ways.
| Some look like motor scooters with pedals, others pedal
| bikes with a motor. Seems to be fashion rather than
| functionality that determines which.
| analog31 wrote:
| At least here in the states, the "moped" was not meant to
| be pedaled while in motion. It was for starting the
| motor. The gear ratio was too low to be useful while
| riding.
|
| The Honda Spree, with electric starter and centrifugal
| clutch, put an end to mopeds.
| seltzered_ wrote:
| See also bike2.dk as a 'chainless electric bicycle' series hybrid
| bicycle drivetrain -
| https://www.youtube.com/watch?v=4JKOKpg21dQ&t=313s (2016).
|
| Like others, it didn't at first make sense to me when thinking
| about efficiency losses and material complexity, but later
| realized it might have a place in certain battery-electric
| delivery bike applications where the majority of the power will
| be coming from a pre-charged battery. Think about how one could,
| in a worst off case, charge the bike pedaling in standsill
| position in a shaded area (while reading a book or using your
| phone) before trying to continue using the bike.
| masklinn wrote:
| It also can make a lot of sense if you're assuming ebike, and
| thus that the material complexity is already 90% there (if not
| more, a generator is not really a complex beast after all).
|
| And between the limited maintenance and the ebike-engine,
| direct-drive efficiency also becomes less of a concern.
| germinalphrase wrote:
| Does peddling really generate enough watts to fully power the
| rear wheel at comparable speed/torque level?
| user32489318 wrote:
| I would say that will depend on the rider and the level of pain
| they want to go through. Some ballpark figures: A pro-level
| male athlete can comfortable put out 200W without breaking a
| sweat. All-out effort for an elite rider (male) is upwards of
| 400W for 20+ min effort. (According to Strava records Van der
| Poel has put out 450W for 20min) A pro-level female rider can
| put out 300-350W continuously for an hour (and longer) in all-
| out effort. A semi-untrained (male) individual can put out
| ~150-200W on average for an hour of all-out effort. 180W is
| ~30km/h for an amateur rider in a comfort position on a
| endurance geometry racing bike with system weight of 80kg. A
| semi-untrained rider would consider 90-130W acceptable for a
| leisure ride.
|
| These figures are quite less useless, you've to put them in
| perspective with the system weight (bike + rider), just can't
| escape physics.
| messe wrote:
| I don't see how it couldn't. I mean, the wheels spin when you
| pedal on a normal bike, don't they?
| nradov wrote:
| No it's obviously less efficient than a mechanical drive. The
| point is that it gives more flexibility in design and energy
| management, and may be more mechanically robust. So the
| benefits can be worth the loss of efficiency for certain
| applications.
| Tostino wrote:
| The applications where additional batteries are not
| preferable to this complicated system are vanishingly slim
| IMO. I've seen this proposed over the years over and over,
| with people designing similar systems, and i've always ended
| up disappointed in the objective performance characteristics
| of them.
| germinalphrase wrote:
| Fair enough. It's certainly interesting.
| Lanrei wrote:
| Would it still be a bicycle if the pedals aren't connected to the
| drive? This configuration would make it more like a scooter with
| a pedal generator.
| WelcomeShorty wrote:
| "it's an electric motorcycle with a foot-operated charging
| crank."
| DonHopkins wrote:
| And you can use it to charge your OLPC XO-1! ;)
| csunbird wrote:
| Exactly, I am not sure if they would be allowed to be in the
| bicycle lanes in European countries (or at least in Germany)
| buovjaga wrote:
| See these:
|
| https://leva-eu.com/eu-commission-finally-confirms-series-
| hy...
|
| https://downtown-mag.com/en/new-eu-regulation-declares-
| ebike...
|
| Quote from the second article:
|
| The EU Commission's statement ends an almost 5-year problem
| that has unsettled and set back manufacturers investing in
| the development of series hybrid bicycles. Undoubtedly, this
| technology is still a niche product but manufacturers such as
| automotive supplier Schaeffler are increasingly investing in
| this technology.
| usrusr wrote:
| Electric scooters are already allowed (unfortunately for
| cyclists...), why would adding a charge-crank change that?
|
| I'd be more concerned about how a drive system like that
| would subtly fail to tickle the endorphine feedback loops the
| way a bike does. I don't think you'd notice on a conscious
| level, chances are you might even think you enjoy getting
| button-press acceleration from the battery buffer, but riding
| a bike has an immediacy that is close to the walking/running
| evolution has wired us for. I doubt that an e-scooter fueled
| by an ergometer generator would come anywhere close. I'm
| somewhat involved with a cycling vacation business and the
| way a day of being exposed to those feedback loops makes
| everybody involved happy that business feels almost like
| cheating. I really doubt that "ergometer driven e-scooter"
| could ever come anywhere close to that. But, well, Schaeffler
| isn't aiming at recreational cycling at all, just at the last
| mile delivery industry. I could not even guess wether it
| would make those jobs even more miserable or not.
| masklinn wrote:
| Ignoring that they're not too different from an e-scooter,
| these could _trivially_ only power the cycle when the user is
| actively pedalling, which would be the main issue with
| respect to pedelec classification.
|
| Though interestingly it could also put a hard limit on upper
| speed, since "motor assistance" has to cutoff at 25km/h. A
| series hybrid bike might be considered to _only_ work off of
| motor assistance (ignoring downhill).
| mikepurvis wrote:
| Do they not allow e-bikes in those? That seems surprising,
| given how important e-bikes and pedal-assists have been (or
| have been represented as being) for broadening the
| accessibility of cycling.
|
| A quick googling led me to this statement about Germany and
| e-bikes:
|
| "Insurance and license plates are required. The maximum motor
| output is 500 watts for e-bikes. Also, e-bike drivers must
| use bike lanes unless there are none, in which case they are
| allowed to ride on the roads."
|
| From: https://adoebike.it/en/an-ultimate-guide-to-e-bike-
| laws-in-e...
| lm28469 wrote:
| Of course e bikes are allowed, but as you said you need an
| insurance + they must be capped to 25kmh and only provide
| power when the user is actively pedalling.
| throwaway14356 wrote:
| in NL we have 3 kinds rly. 1) electrical assist that is
| limited to matching the riders output and limited in
| speed. They are cosidered bicycles. 2) e-bikes that are
| considered mopeds and 3) electric motorcycles.
| croon wrote:
| E-bikes are generally allowed as they 1) work like regular
| bikes. 2) only allowed if they're pedal assisted, ie not
| mopeds.
| Fradow wrote:
| That differs from country to country.
|
| In France, pedelecs (pedal-assist, assist is capped to
| 25km/h) are allowed on bike lanes, but speed bikes (not
| limited to 25km/h, they can reach the same speed as cars in
| cities, often 50km/h, and do not require pedaling) are not
| allowed on bike lanes.
|
| For all intent and purpose, a speed bike (or however you
| call it) is an electric moped.
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