View Single Post
Old 06-06-2010, 12:59 AM
Smallwheels Smallwheels is offline
Motorized Bicycle Member
Join Date: Dec 2008
Location: Montana
Posts: 36
Question Friction Drive Kit Questions

I'm on my third week of owning a friction drive kit. Overall I like the concept but it's driving me to anger regularly. Not so much about the kit yet, it's the rain. There are only about eleven inches of rainfall in Montana each year and forty-five inches of snow. It seems like those eleven inches are falling into the months of late May and June. That means I'm pedaling with the motor almost all the time just to keep it rolling without the drive roller slipping.

On the dry days it's great with a few exceptions.

My drive roller had a diamond pattern on it. With just about one-hundred-fifty miles on it the diamond pattern is no longer as sharp as when new. It now feels smooth with just little bumps. How normal is it for such quick wear on a drive roller?

Another problem is the rear motor mount bolts that go into the fender mount holes keep breaking. Each time it does that I must take it apart and put it together with new bolts. Now one bolt broke off and the remainder of it is still stuck in the frame.

My solution has been to create a new mounting point. I've found some thick metal and put holes in it. One big hole goes on the rear axle and the other hole is for the rear support. I drilled it out to hold a bigger 1/4 inch bolt. That should stop the breaking bolts.

My next problem is that the front mount keeps twisting no matter how tight I clamp it. This causes the drive roller to move away from being perpendicular to the tire. Is that common with friction drive kits?

The last problem is that my kit required extension bars to move it farther away from the seat. This was needed because my frame has low rear seat stays and the seat down tube is on an angle that is more laid back than conventional bicycles.

The extension bars need to be kept tight. They hold the front part of the friction kit high enough so that the kit can be lifted off the tire when the rear quick release is loosened. My problem is that the motor side of the kit keeps twisting downward which contributes to the roller pressing more on the left side of the tire instead of the center. I'm wondering if I will need to use super glue to make this stop moving. Has anybody else experienced this and solved the problem?

On the dry days when nothing is shifting or no bolts are snapping, the kit does a good job moving me down the road at about twenty miles per hour (mph). I have the one inch roller to help me get into the wind and up some hills.

I've bought a new rear tire that should give the roller a bit more grip. I might put it on this Sunday. Right now I'm using a foam inner tube which means no flats. The new tire is too big for it so I'll need to revert to a pneumatic tube to fill the tire. It will be an extra thick tube with slime AND a tire liner.
Reply With Quote