Kepler Friction drive comes of age.

[falcongsr]

I am not sure that trike is a good candidate for friction drive. Do you already have a solution to mount the motor to the frame in a way that will allow it to press against the wheel?

You'll also need to switch to a slick rear tire. I used Continential Gatorskin in the past, but it performs so poorly in wet conditions that the motor would just spin against it unless it was perfectly dry. I'm looking for a better tire now, but my LBS does not stock any in the size I need.

 

[Ecyclist]

I'm confident that I can come up with a mount for my trike. I would most likely incorporate a motor locking system to reduce the motor spinning to minimum. All my riding will be in dry weather anyways. I have a mid drive for everything else. I use Schwalbe Kojak tires on my trike. With tape like this I should be OK.

3M Safety-Walk 2 in. x 5 yds. Gray Home and Recreation Tread 7647NA - The Home Depot

Provide an essential and ultimate addition to your toolbox by selecting this affordable 3M SafetyWalk Gray Home and Recreation Tread.

www.homedepot.com

 

[Chalo]

It seems like an esoteric corner case if the friction drive's light weight is worth enough to offset its awful gross efficiency and extreme tire wear. I can't imagine a situation where it would be preferable to using a small geared hub motor.

 

[Ecyclist]

No it wouldn't, but you go ahead.

 

[Ecyclist]

I am not sure that trike is a good candidate for friction drive. Do you already have a solution to mount the motor to the frame in a way that will allow it to press against the wheel?

You'll also need to switch to a slick rear tire. I used Continential Gatorskin in the past, but it performs so poorly in wet conditions that the motor would just spin against it unless it was perfectly dry. I'm looking for a better tire now, but my LBS does not stock any in the size I need.

I didn't see yes from you, so I will look into programming Raspberry Pi or Arduino. I have some experience with that. No problem.

 

[falcongsr]

I have no clue how to program a Raspberry Pi, but I think that I could build even better friction drive system. Would you be interested in working on this project?

Sorry - I got confused. You asked if I would be interested in working on your trike project to make an even better friction drive. Kepler did an amazing amount of research and shared all of it here. I think he explored the limits of what is possible with the approach.

I didn't see yes from you, so I will look into programming Raspberry Pi or Arduino. I have some experience with that. No problem.

I am happy to explain what I did and even share my micropython code for my Raspberry Pi Pico. I replaced the Arduino he sold us with the Pi Pico which is a $4 microcontroller, and not a Raspberry Pi that runs an operating system.

I abandoned the Arduino with visuino code that Kepler used because I wanted to change how it responds to button presses, and this was a quicker way for me to tune it to my liking. All this does is generate the signal to control the VESC. This throttle controller is just one part of Kepler's friction drive system.

If you develop your own friction drive I hope you share your progress here, as I am sure the community will be more than happy to provide feedback! I don't check here very often right now due to other obligations, but I will check in when I can.

edit - your Avian build looks amazing!!!

 

[Ecyclist]

Kepler did a fantastic job with his friction drive, but it looks like he found something more interesting or rewarding to do. Buying his drive is no longer an option. I sent you a PM.

 

[lnanek]

China still makes friction drives if you want one. Lots of reviews of a modern one here:

REVIEW: QR-E 250W ELECTRIC BOOSTER BICYCLE MOTOR AND B60i AND B70 BATTERY

(By a bicyclist with a common man's (not an engineer's or bicycle tech's) POV regarding bicycles and motors used to assist bicycling. In other words: Press button - how fast can it go and for how long, and will it take me up that damn hill without too much effort on my part.) I was looking...

forums.electricbikereview.com

I have plenty of hub motors and consider them much simpler than friction drives, so no interest from me.

 

[Ecyclist]

China still makes friction drives if you want one. Lots of reviews of a modern one here:

REVIEW: QR-E 250W ELECTRIC BOOSTER BICYCLE MOTOR AND B60i AND B70 BATTERY

(By a bicyclist with a common man's (not an engineer's or bicycle tech's) POV regarding bicycles and motors used to assist bicycling. In other words: Press button - how fast can it go and for how long, and will it take me up that damn hill without too much effort on my part.) I was looking...

forums.electricbikereview.com

I have plenty of hub motors and consider them much simpler than friction drives, so no interest from me.

Thanks for the info.
I have two mid drives, two hub drives and I would like to build my own friction drive.
Chinese factory kit would be my last choice. Still it's an option.