Easy friction drive from scooter

[pocdragon]

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]

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. The wheel on wheel is a great friction drive. Your looks nide The one I built was using a bumble bee kit and it was excellent till I broke the drive shaft. I later found out why, my own fault. It might have run for years if I had designed it better. Yours looks good.

 

[wayne z]

Awesome build! I think wheel on wheel is a great idea.
I've been following Deacon's work, and I have got some ideas of my own that I want to try.

 

[pocdragon]

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.

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]

There are so many variations with friction drive and they are all so much simpler than the other drives. I have been working with this 2.5 HF engine. It has the guts to pull all the hills but it still runs at about twenty miles per hour. Which is all I want to do anyway.

One thing I might mention in passing. I have been having an awful time with kickstands. The motors want to pull the bike over, So I put an L bracket on the rear axle. Then mounted a kickstand to it. At that point it supports the motor directly and solves all the rear engine kickstand problems I was having.

Still love the build

 

[pocdragon]

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

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]

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.

 

[deacon]

Since I have used the rear axle kick stand a couple of weeks I decided to do some welding to keep it in place, so I welded an extension under the nut that holds the kick stand on. The extension gives me an inch piece of metal behind the L bracket to attach my little trailer to. I didn't want to lose the ability to pull my trailer up to buy gasoline and stuff.

 

[pocdragon]

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.

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

 

[deacon]

let us know how that rear kickstand works for you. That might be something that would be usable by a lot of guys. I just know that it works for me, I'm not sure if it would work generically.

 

[cannonball2]

I have 2 standard kick stands on one of my bikes, the usual position and the rear axle, works fine. On the Lifan bike, which is much heavier, I have a center stand that is very stable. Added benefit, I can remove the front wheel while its on the stand and it just sits there.

 

[deacon]

very cool. I had to replace the end on my big bike kickstand since I had been running shorter tires. I welding a nut on the end of the kickstand then welded a 3/4 inch pipe nipple on the end of the kick stand it is much more stable. I am thinking I might try welding more points onto my standard kick stands from not on to see how that does. Old brake calipers have lots of funky angles.

 

[pocdragon]

update on my GF's bmx bike

new wheels and front suspension

 

[deacon]

I really do love the look of that bike.