French company Cixi have produced a drive unit that converts your pedal strokes into power and controls the output of the rear hub motor. Called PERS and now offered on ICE trike models.
https://www.cixi.life/pers-technology
https://www.icetrikes.co/e-assist/pers-chainless-e-assist-system-2
CityCyclingEdinburgh Forum » Cycling News
Chainless e-bike system
(10 posts)-
Posted 2 months ago #
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Intriguing - legally an EAPC must"...be fitted with pedals by means of which it is capable of being propelled". Is that really the case here? I assume once the battery is dead then the bike won't move, regardless of how hard you pedal.
I mean, I doubt any regulator or police officer would really care - but it would be interesting to find out. Also, I assume you really could get stuck when the battery dies.
Posted 2 months ago # -
I've seen a few of these "digital drive system" concepts now and I'll admit to just not getting it. They seem like a weird artifact of the odd way EAPCs are defined in law, and in practice what is the advantage? Combining human input with the mechanical advantage of gears *and* and electric assist is surely more efficient than what is in practice a remote-controlled rear hub motor doing all the work alone even with the pedals being a fancy dynamo to put charge into your battery. They highlight the lack of a greasy chain and drivetrain to maintain, but surely at the sort of pricepoint these will command you'd be riding something with a cased belt combined with hub gears that are just as low maintenance.
Actually Morningsider, their website claims the bike will function even on a flat battery because pedalling will ostensibly transfer power directly to the motor in that situation. How they're getting *enough* power to the motor in such an arrangement I don't have a clue.
I suppose it might have some value for extremely atypical configurations where a traditional drivetrain would be a pain, but for a regular bike(and they're very keen on presenting their regular bikes and bakfiets cargo models on their site)? Ehhh.
The "anti-theft" thing is also kind of funny, as if a thief wouldn't just pick it up and walk off to bypass the doubtless rudimentary motor locking at their later convenience.
Posted 2 months ago # -
I mean it looks cool but at it's heart they've just turned the cranks into a throttle, which again makes that an obvious target for hacking/de-regulating the system.
Posted 2 months ago # -
@Yodhrin - thanks. I am also doubtful you could get this set-up going with a dead battery. Having had a go on a cycle powered cinema and cycle powered smoothie machine, it's hard to see how you could pedal hard enough to produce the power needed to drive an e-bike motor for any length of time.
I think when you lose the physical connection between pedal and drive wheel then it is no longer a true bike.
Posted 2 months ago # -
@Yodhrin "....their website claims the bike will function even on a flat battery because pedalling will ostensibly transfer power directly to the motor in that situation. How they're getting *enough* power to the motor in such an arrangement I don't have a clue."
Yes agree with that. Directly powering via chain always better.
We're yet to get an order ... trike market is mainly for adapted riding so things like reverse gear is useful. Less moving components good too. The pedals are a kind of throttle but I belive there is 'feel' in system so it replicates the effort based on assist level. 700Wh battery surely will have less range although regenerative braking might put in 50Wh or so back.
Taking the chain away is heresy in the bike world I know. Just posted on Bsky!
On the e-bike scene people end up not using full range of gears and mulching up hubs and cassettes. Edinburgh based IntraDrive now doing geared motor to simplify this (tough but repairable unit). Swapping a motor like for like is not hard job (for Joe T!).Posted 2 months ago # -
Aye I read about Intradrive a while ago it seemed like an interesting concept. Hopefully they eventually develop some direct to consumer models, it'd be a great option to replace EOL mid drive motors.
Posted 2 months ago # -
I suppose from a legal standpoint there is no minimum speed or time requirements for being capable of propelling using the pedals. Provided the motor can switch on with just a few watts they likely meet the requirements.
Posted 2 months ago # -
Further feedback on how this performs is that it's fine up to the cut out at 25kmph. Beyond that pedalling is hard as the pedal generator has lower efficiency than a chain. Users of e-bike systems know that switching the assist level to zero frees up the drive. On a wired system you get little to no output beyond the cut off (apparently). Your excess human power can't be harnessed?
For some adaptive cycling this won't matter with the bonus of reverse gear.Posted 2 months ago # -
As an alternative, how about electric assist chain drive up to 10mph, electric with chain drive generation above 10mph, with twin (but not identical) motors and all-wheel drive? I'm quite a bit in love with the Electrom electric light vehicle:
https://www.electrom.ca/innovations/
Not available outside Canada or USA, yet, unless you have a small fortune to spend on importing.
Posted 2 months ago #
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