somebody build me

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
Okay I need a friction drive for the china engine. I am getting so sick of the chain drive I don't know what to do. So here is what I need.

Take an alum or steel channel.
Use brass busings to run a shaft through with a sprocket on the motor side to drive a shaft with a friction drive roller on it. You might half to do a gear thing to make it change directions but it shouldn't be all that hard to do. I can rig the tie downs no problem. It would be just a bolt down on the wishbone behind the seat, then a couple of down rods to the rear axle. Nothing to it for someone with a good shop.

That kind of rig would eliminate broken spokes, chains jumping off in he middle of traffic, and give another option for the china bike kit. I know I'm the only one with a desire to run friction drive these days, but I swear I think it is more dependable.

The reason I like the china girl engine for the power source is the the clutch. A motors that sit on the tire running continually will wear spots in the tire for sure, but the clutch would make it like my electric where I just shut it down before it spins.

So build it and they will come, at least I will if the price is right.

Come on Norman you and a lot of other guys can do this no sweat
 
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Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
6,627
436
83
Los Angeles, CA.
You might not have to make it change directions! These engines should run in both!
(I don't know what might happen with any oilling holes inside?)
But it should run backward! (I know my RC car engines do.)
Actually, you might have a problem with the ignition?
Has anyone ever tried to run one of these engines backward??? :confused:
 
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deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
I never even considered that it might run backwards. Now wouldn't that be neat for a friction drive kit. just an alum channel with a hole drilled straight though Probably have to weld the drive wheel on after it was inside the channel. or maybe not I don't have enough experience with these things to know.

how about a long bolt inserted through the pedal side, through a bushing, then through the friction drive wheel, then through the channel then double bolt a sprocket on loose enough to move inside the bushing.

Or just drill and put a pin through the drive wheel to hold it. That is if the motor would run backwards. I might be able to buy all the parts off the shelf.
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
That would be great, because I think I have figured out an easy way to make a drive wheel assembly from the rear axle of a coaster bike. I need to check on a sprocket.

It looks like you can take two big butted steel shelf L brackets and cut and weld them to a large channel configuration. They have threads on each end so in theory it would but just a matter of some nuts in the right places.

The sprocket would have to go inside the frame because of the wishbone of the bike. Any guess as to what size sprocket would be good to use. Since it is friction my guess it that it wouldn't matter too much.
 

Skyliner70cc

Member
Mar 8, 2008
138
0
16
Deacon,
I'm sorry to hear you are having problems. I have yet to experience any of those problems on well over 2 dozen builds under my belt. I typically put 50-100 miles on a bike before I market it for sale.

Each of your issues is easily solved with a little more attention during the build. Good luck in pursuing a friction drive.
 

toytime

New Member
Mar 20, 2008
550
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Ontario
Hey deacan, It's very hard to put into words but an air filled small rubber tire works great as a "friction drive" I have done it and it NEVER spins or wears bald spots into your tire. I used a 8 inch tire with sprocket attached. Have you ever noticed that most rides use this method at your local fairgrounds! If you face the engine towards the rear, you don't have to worry about jackshafts and running backwards. It's not as foolish as it may sound.
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
thanks skyliner...

Toy wouldn't reversing the engine cause the chain to come out facing the front of the bike.

I am using a plastic wheel from a caster now on my electric bike.

I had planned to have the sprocket welded right to the drive wheel either way I go. Whether the wheel revolves on the shaft or the shaft revolves in the bracket, I think I'm going to go with the sprocket welded to the drive wheel.
 
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toytime

New Member
Mar 20, 2008
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Yes it would but I'm talking about a rear rack setup. If you were looking at the bike from the front , you would see a seat, the "drive wheel" and then the engine.
The set up I built was with an electric motor so I was able to turn the motor upside down, solving the bike wanting to go in reverse, if you know what I mean. It would be interesting to see a china girl run upside down, I think the carb would have to be mounted in reverse and everything would be fine. As far as welding your wheel, have a look at the cheap electric scooters. All the parts you need are there, including a small drive wheel with a sprocket attached. It's very hard to put into words but I will help if you ask.
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
Ah I have built several bikes that way yes. I am talking about converting the china gasoline bike to friction drive. If I can do it easily and inexpensively it will solve my intermittent chain problems.

I love my electric bike but the range just isn't there for me.

by the way on most brush type electric bikes I just change the wiring to the motor to reverse the direction of the engine.
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
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north carolina
cool let me know im really curious. If I do it first I'll let you know but it will be a while before i get it ready
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
237
63
up north now
deacon- I'm a little puzzled as to why you have so many chain problems. How tight do you have the chain? Have you tried replacing the nuts and bolts on the tensioner with good hardware and that includes using the cupped washers behind the two tensioner pieces?

In well over a thousand miles I have only had "annoying noise" as a problem with my tensioner and that was mostly due to not being able to perfectly center the sprocket.

If we could get to the bottom of your tensioner problems I think you'd be a lot happier with your motorized bicycle overall.
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
Okay I don't use the tensioner. All of them have jammed at the roller. One of them ended up in the spokes.

Now the chain binds when I back the bike up even with the clutch in. It will pop and jump off the sprocket. It goes right back on no sweat.

I have never liked this chain drive system. The darn sprocket on the rear wheel reminds me of a tumor. I think the frame somehow causes the wheel to get twisted in the mount as it runs. Im going to take a good look today.

I might have to switch everything over to the huffy I had planned to use for a spare. I'm going to give that wheel and frame one more chance. I never had this problem with the sissy schwinn, that's why I think it might be the frame.

I really would prefer friction drive to be honest. I might just sell this thing for parts on ebay and buy your engine if you still have it lol...

I have a controller and throttle coming for my electric setup. If that gets me a little more range from the battery trailer, I might just dump gas all together. I just went to this rig for the range.
 
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Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
6,627
436
83
Los Angeles, CA.
Deacon, does your rear sprocket "wobble" at all? :confused:
I always make a effort to make my sprockets as perfect as possible, & I have only ever had a chain come off once. (on my very first bike, the first time I started it!)

We would hate to see you go over to the "dark side" forever... (electric). rotfl
:ride2:
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
Okay I reset the motor since I had done that earlier as part of the bike check up a month ago. I tightened the wheel's axle it was loose, I changed out the knobby tire that was split, I didn't know. At this time I can get about a block before it throws the chain. I tightened and loosened the chain, I added more spacers and removed all the spacers one at a time. I got a less than a block. The only thing I didn't do is to change out the rear wheel. It is possible that the wheel got bent from running it with a loose axle. I'm going to do that tomorrow. I have decided to go to the full 24inch wheel. If I had a 24 I would go there instead.

The bike will more difficult to mount and dismount but it will still be pedal friendly so thats a good thing. I'm going to have to redo the bike chain again I think. It is a pain in the butt but I added links so that I could get the motor chain really tight. That didn't help. I REFUSE to put the tension back on the motor side. If changing out the wheel doesn't do it, someone else will own the engine next week.

I have some serious e bike parts coming in this week so i have to work on that as well.

I have given up on a friction drive. I decided the compression on the engine is too great to start with a friction drive. I would need a pull start which is just more money down the proverbial rat hole. I think Gasoline and deacons don't mix.
 

toytime

New Member
Mar 20, 2008
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Earlier I was trying to explain what I built a couple of years ago. When you look at this pic, try to imagine it mounted to the rear as you would mount a rear rack or carrier, I'm not sure of the proper name. If you were to turn this upside down, the bike would move forward as it turned your bike wheel.
All it takes is a couple of hours work, a drill, two metal pipes or tubes that mount to the wheel nuts and a hacksaw. The air pressure can be adjusted to get the right pressure so that the drive wheel turns your bike wheel without EVER spinning in place. Rubber on rubber is by far the best "friction drive" you will ever come across.
 

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deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
damn that looks heavy. lol... Cool but heavy

I switched out the wheels and sure enough that was the problem. of course now I have a bike that is twice as tall and moves way too fast. I have a couple of new 20" coaster wheels. I think I might ride this for a week if it doesn't get any better feeling I'll switch wheels again.

Still it does move and there is no grinding sound like before. I also went about five blocks and the chain stayed on. made a heck of a racket but it stayed on. I think the other one in addition to working loose again also had the coaster brake dragging. That was the lurching I felt.

I am using the tensioner temp on the bike side. that will go when I get around to shortening the pedal chain. I would still rather have a friction drive. next kit I get will be friction I guarantee it.

I still have to work on the ebike when I get the new parts.
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
Thanks for all the help guys, I probably never would have gotten motivated to fix switch that wheel without you guys kicking me in the butt.