Front Wheel Drive Friction Bike

EvilJimChicken

EvilJimChicken

New Member
Just finished this bike and got it running how I want it. I wanted to make something front wheel drive to reduce the complexity of the spindle engagement and allow me to use the rack for transporting cargo. The bike is an early 70's Schwinn varsity and the engine is from a scooter x (49cc). The spindle is a starter cup from one of those 200cc clone engines and the handle to engage the spindle is bamboo. I'm not sure how clearly it comes across in the pictures, but when the spindle engagement handle is lifted all the way it locks into place. It took some time to get the pressure on the tire just right so that it can still slip just a little for smoother acceleration. The small amount of slippage especially helps due to the high speed gearing. One of the biggest problems I have now is that because of the increased fork weight, the wheel flops over when its on the kick stand. Feel free to ask any questions or suggest improvements, thanks for looking/reading!
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ended up removing the gas tank bracket to the frame
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If you want to go faster, use a 1" spindle.

I had a front friction drive bike.

To prevent the bike from falling down when parked, tie both handle grips with rope to your fuel tank mounts.
 
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5-7HEAVEN said:
If you want to go faster, use a 1" spindle.

I had a front friction drive bike.

To prevent the bike from falling down when parked, tie both handle grips with rope to your fuel tank mounts.
Click to expand...

I actually really like having an oversize spindle, at low speed it almost sounds like a 4 stroke and is incredibly quiet. It already has enough power for me but I may put a smaller one on in the future to help with hills.

As for the front wheel falling over when parked, i'm thinking about putting a spring connecting the handlebars to the frame to offset the weight. Similar to the spring just above the front wheel of this picture.
scad_mockup-768x519.png
 
Orrr, you could weld L-brackets to the
fork and headset and lock it when parked.

Besides keeping your bike from falling,
this locked-steering feature deters theft.
 
I read where previously stated to keep the front wheel straight while kick stand down so your bike does not tip over by front heavy weight. On my 130 lb Briggs off road bike, I noticed while using my bikes using center stand and with rear wheel removed to be working on stuff, I had to secure the front to stay straight. I forgot to mention that the bike with out the rear wheel on the center stand also had a 25 lb weight belt draped over the front wheel so it would stay pivoted forward. I just use a bungee cord from the front wheel to the frame which keeps the front wheel straight. Then I can work on cleaning belts, chains, sprocket, and pulleys after they get caked in mud or dust.
 
When I had friction drives on both wheels, the bike felt tipsy when parked. I went thru several bike stands before finding one that worked well.

However, the fork ALWAYS twisted to the left when parked. The bike fell often.

I finally got the idea of tying both handlebar grips onto the top tube, when parked.

The bike never fell again, when parked.
 
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