Re:Show HN: I Designed and Built an eBike
by ghostly_s on Wednesday February 23, 2022 @06:08PM
(#30447920)
I was more concerned about the pedals being spun about by a high-torque motor and banging into your shins...
Re:Show HN: I Designed and Built an eBike
by VectorLock on Wednesday February 23, 2022 @07:34PM
(#30448782)
There is a freewheel on there, it doesn't talk about how its implemented though and I'm interested in it as well.
Re:Show HN: I Designed and Built an eBike
by gkasev on Thursday February 24, 2022 @03:48AM
(#30452400)
The basic idea for the freewheeling chainring comes from tandem bikes, where one person should be able to pedal, while the second one doesn't do anything. I have never ridden a tandem bike, but this is where I got the idea.
There is also another detail, that you need to know, in order to understand how it all works.
Trial bikes (not trail bikes) usually have a special kind of drivetrain, where the freewheel is mounted on the crank and not the rear wheel. This allows for a very small rear wheel sprocket and extremely high gear ratios.
So to make this work, I used a trial bike crank [1] on which I'm mounting a special purpose freewheel [2]. The chainrings are mounted to the freewheel using this adapter [3].
[1] https://sickbikeparts.com/cranks-freewheel-isis-crank-set/
[2] https://sickbikeparts.com/front-freewheel-heavy-duty/
[3] https://sickbikeparts.com/freewheel-spider-4-arm-104-mm/
Re:Show HN: I Designed and Built an eBike
by KennyBlanken on Wednesday February 23, 2022 @08:48PM
(#30449307)
> It looks like it has a chainring clutch
The motor sticks out uncomfortably close to the pedals and particularly on a MTB I could see a rider accidentally stepping on it...and it looks like an outrunner, so that would also be quite bad, as the foot would get launched backwards pretty violently.
This is a lot of effort compared to just bolting on a Baofang mid-drive motor. The components are also placed such that unless you have a pretty good front fender, they'll be covered in crap in no time.