Easy friction drive from scooter

hello all

this is one of my first couple posts,

i built a kit bike for myself, but then my GF wanted one too
but my bike was much to big for her to get on/off and ride properly

so my base bike is a BMX wally-world bike


so using an old 32cc sit scooter like this:


i chopped the drivetrain off

upgraded from a 9'' wheel to an 11.5'' wheel from a pocketbike

raised the gear ratio for a higher top speed (because when mounted on a bike low speed can be achieved by pedals. a power take off isnt necessary)

i used the rear wheel from the scooter as the drive roller on the BMX bike wheel. the only way it would work is if the drive-train was facing backward. this works in my favor when using a friction drive. the weight of the engine balances on the wheel and is supported by a hinge at the seat tube


pull start /electric start with battery

super easy to maintain
very relyable! starts on the 3rd pull after choke every time (i had been riding the scooter a long while before i cut it up for this project)




any questions/comments are welcome thanks!

deacon said:

Those are the best friction drive systems I ever built. If you don't have a clutch you can set it up so the whole things lifts and inch or so off the wheel.

Click to expand...

first off deacon, i am honored and in awe. your builds have been an inspiration, and motivation.

sofar this thing runs like a dream (compared to my HT powered bike)
in this build i needed to have a pullstart/ centrifugal clutch so my gf wouldent have to diddle the clutch when slowing down, brakes were more important, and i didnt want anyone getting levers confused.

before i decided on wheel to wheel drive my bike had a bike peg friction drive with a 25cc craftsman motor


the motor is bolted to a heavy duty gate hinge (which was the most cost effective pivot point i could come up with)
never got it running because of the clutch motion of mooving the engine drive to the wheel became complicated (hand clutch between your legs is mighty sketchy)



im kinda bummed, this setup was super light and cleanly attached

cheers!

deacon said:

One thing I might mention in passing. I have been having an awful time with kickstands.

Click to expand...

haha, thats my next challenge is so solve my kickstand problem, haha its like your in my head man!

shows from wisdom i guess, using the same tecniques we encounter the same problems. i usually have to lean my bike on somthing but now im gonna try the lbracket trick, thanks Deacon!

deacon said:

By the way you know if you built a wedge shaped cover for your wheel on wheel drive it would have a very classy look. Kind of a back to the future look to it.

Click to expand...

that doesnt sound like a half bad idea, also saves hands and loose clothing from the drive setup and gas lines

if you notice the first pic in the thread of the blue scooter, if you can see the bottom cover (not the higher suitcase bit) for the engine, i have that mavbe i can fashion it back onto itself, tho i did chop the thing down to size and then bolt a great-hulking bracket to... hmmmm

theres also a bit of seat clearence issue, the plastic case that would be against your back is the electronics for the electric start and key so it would be needed to be hidden, but that wont be an issue when i swap this poor tired relyable 32cc motor for a 50cc cag motor from the pocket bike i used for parts, it was left in the rain (i took the exaust off and water came out
so i need to dismantel most of it to dry it well.
new carb tho
updates soon

update on my GF's bmx bike

new wheels and front suspension