Chain won't stay on

[chipofsc]

I'm have problems keeping the chain on my old mini Bike. Replaced the wheel bearings and it looks like it is in line with the clutch. The rear sprocket my have a little wave in it. When I spin the rear wheel with out the chain it is smooth but with the chain it has a little tight spot. Maybe new chain and sprocket????

 

[bandit 40]

Could be a twist in the chain or possibly a link or two with damage.

 

[The Restore Kid]

The rear sprocket is out of round to the wheel.. As it rolls it oscillates so one side will be real tight, 180 degrees out it's real loose.. A spring tensioned adjuster wheel will do away with slight changes in chain tension, just always as tight as it needs to be..

 

[toomanytoys]

I had this problem on one. Figured out the frame was flexing under hard acceleration.

I put a nice spring adjustable tensioner on it. Solved all my problems.

 

[chipofsc]

I found the rear sprocket was not centered on the wheel. In the process of centering the sprocket and plan on installing a few Dow pins in the sprocket to hold it in place. Sounds good in my head anyway.

 

[Havasu Dave]

I found the rear sprocket was not centered on the wheel. In the process of centering the sprocket and plan on installing a few Dow pins in the sprocket to hold it in place. Sounds good in my head anyway.

I always have to center my sprockets. I slightly loosed the bolts, then use a rubber mallet to center them, then tighten. It holds fine afterward...but then I also run chains loose to mitigate the slop on old wheels and sprockets.

 

[buckeye]

Good tip Dave.:thumbsup:

 

[Havasu Dave]

Good tip Dave.:thumbsup:

Somewhere here there are several write ups on chain and sprocket adjustment. That's where I got the info from.

 

[chipofsc]

I centered it and tighten the bolts but it would still move so I drilled a 1/4" hold across from each other and install two Dow pins. Seems to be holding so far. It's not perfect but the chain is still on.

 

[chipofsc]

Okay the chain is not on anymore. It seem to come off when the clutch locks up and starts to pull hard. If I drive it real easy it will stay on. My next try is to replace the chain im sure finding a rear sprocket of this old bike will be a task. Trying to sell it but can't until I get all the bugs out.