3 ms·

So it drives the pedal shaft? Isn't that a safety hazard?

KennyBlanken 5y ago
It looks like it has a chainring clutch, though without a chainguard cover, you have the risk of clothing, body parts, shoelaces, etc getting sucked into the chain, yeah. 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.
- ghostly_s 5y ago
  I was more concerned about the pedals being spun about by a high-torque motor and banging into your shins...
  - VectorLock 5y ago
    There is a freewheel on there, it doesn't talk about how its implemented though and I'm interested in it as well.
    - gkasev 5y ago
      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/ https://sickbikeparts.com/cranks-freewheel-isis-crank-set/ [2] https://sickbikeparts.com/front-freewheel-heavy-duty/ https://sickbikeparts.com/front-freewheel-heavy-duty/ [3] https://sickbikeparts.com/freewheel-spider-4-arm-104-mm/ https://sickbikeparts.com/freewheel-spider-4-arm-104-mm/
  - KennyBlanken 5y ago
    > It looks like it has a chainring clutch
gkasev 5y ago
There is a freewheel between the chainrings and the pedal cranks/shaft. Thus, the pedals can be stationery, while the motor is driving the chainrings.

It looks like it has a chainring clutch, though without a chainguard cover, you have the risk of clothing, body parts, shoelaces, etc getting sucked into the chain, yeah. 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.

ghostly_s 5y ago
I was more concerned about the pedals being spun about by a high-torque motor and banging into your shins...
- VectorLock 5y ago
  There is a freewheel on there, it doesn't talk about how its implemented though and I'm interested in it as well.
  - gkasev 5y ago
    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/ https://sickbikeparts.com/cranks-freewheel-isis-crank-set/ [2] https://sickbikeparts.com/front-freewheel-heavy-duty/ https://sickbikeparts.com/front-freewheel-heavy-duty/ [3] https://sickbikeparts.com/freewheel-spider-4-arm-104-mm/ https://sickbikeparts.com/freewheel-spider-4-arm-104-mm/
- KennyBlanken 5y ago
  > It looks like it has a chainring clutch

gkasev 5y ago

There is a freewheel between the chainrings and the pedal cranks/shaft. Thus, the pedals can be stationery, while the motor is driving the chainrings.