chain ridding up and off sprocket problem...

[davidhoare]

We have our drive system all set up (theoretically) however one of our large kit sprockets seems to have a problem. The chain invariably rides up and off the sprocket after a few rotations. We have checked:
- put face to face, the two sprockets look identical - yet only 1 has this problem
- the 2 axles and sprockets (large and small) are all as parallel and/or perpendicular (depending) as can possibly be given our tools and experience...
- the chains we have tried have no obvious defects
- the chain is tight, but not TOO tight (we think)
- nothing 'wobbles' when it spins

Any other ideas? have others had trouble with the kit sprockets? did we get a dud, or can anyone think of a place to start troubleshooting this that we haven't looked at?

Thanks,
David Hoare
Courtice S.S.

[Gui Cavalcanti]

It sounds like your back-and-forth spacing between sprockets is off a bit. Take the chain off and put the edge of a ruler on one face of the sprocket, pointed towards the mating pinion. You should be able to see really quickly if the sprockets are inline or not if the flat edge of the ruler doesn't touch the face of the pinion sprocket. If they aren't, you need to move the sprocket on the shaft to line up with it's pinion.

[Matt Reiland]

I have seen this happen on sprockets that are 'warped'. While the sprocket may not wobble if the sprocket is not flat the teeth may be prone to throwing the chain off to one side. This type of problem can be solved with some chain guides if you can not get the sprockets to work.

Search the forums for tensioners or chain guides

[Joe Johnson]

Try marking where the chain first rides up. This could give you a clue to the problem.

Also, you may have different "bevels" on the sprocket teeth.

Sometimes these kind of problems go way if you break the edges of the sprockets with a file as they turn.

Finally, lube is important. Make sure grease is allowing things to slide well.

Good luck. I wish I had more for you.

Keep us in the loop if you solve it.

Joe J.

[Sachiel7]

We too are having the same problem with one of our kit sprockets. Everything is lined up fine. Think we got a few duds this year?