chain jumps sprocket

[ratcycle]

I just built my first chopper. I am having chain problems. The chain is jumping of f/r sproket and the chain tensior all at once. It is a new chain. The chain is 3/32 chain. I have tried a 1/8 chain and that didn't mess at all. The sprocket is 3 piece crank sprocket and the rear is a 20" coaster sprocket. Whats going on here? Help

 

[user 135]

3/32" chain is for multigear bikes. The Coaster sprocket needs to use 1/8" chain. Your front could use one or the other depending what you pull it off of.

 

[deorman]

Coaster sprockets are usually designed w/1/8" chain in mind, whereas tensioners and 3-piece cranksets are more likely to be 3/32". If you use 1/8" w/ a tensioner you might need to eliminate any master link to avoid interference w/the cage. How's the alignment? If the sprockets don't line up, and you have slack, the chain is going to "shift" off the same as if a derailleur was doing it. :|

 

[ratcycle]

could i get away with using a 3/32 and a 1/8 chain togahter. The chain tensioner is a rear derilluer cage w/bottom pulley. The chain doesn't run thru it. It push's it down so the chain can mesh with the sprockets. The chain is at the right length. Could i use a half link in the chain or not?

 

[Korporal]

You could put in a half link, but I don't know why if the chain is the correct length. Have you double checked the chain line? If you use 1/8 chain, it will fit on single and multispeed sprockets. It just might be a little wobbly on the multispeed stuff, as the sprocket teeth don't fill the wider chain. But if the chain line is straight, and there's tension, this shouldn't matter.

 

[deorman]

could i get away with using a 3/32 and a 1/8 chain togahter?

No.

 

[deorman]

I suspect your basic problem is trying to run 3/32" chain on a coaster sprocket. The only way it will ever work is if you can find a dedicated thin sprocket. While they do exist, I have no idea where you can get one, or if anyone even manufactures them anymore. I suppose you could try grinding it down 1/32", but I doubt it would work out. My only suggestion is to drop the $15.oo on a 1/8" chain.

 

[Gold Street Customs]

I am having the same problem the rear cogs have square cut teeth and the front three piece sprocket off an old peugoet have more of a point to it, I havn't tried shortening the chain yet, as it looks to be the right tension.