Chain bind

[buickmike]

I've got one of those bikes as you turn the crank alternates chain tension too tight then too loose. I tweeked the chain wheel for lateral r.unout and observed out of round runout not perfect but OK. I have replaced BB cups with generic cups that had to be shimmed. And spun wheel and occasionally while spinning gear will orbit like maybe axle isn't straight. But wheel spins freely and no side to side play. Once I remove guard - chain etc. Ill be full of grease+ no turning back. Any thing else I can check before its all in pieces

 

[buickmike]

Removing chainguard and turning crank revealed a length of chain out of line with the other links maybe 6 links or more.

 

[Boris]

So much for what I was just going to suggest which was to tighten the axle nuts just short of where the chain is at it's tightest. But armed with your new discovery, you probably already know what you need to do, unless you can figure out a way to get those links back in alignment. Vise?

 

[vincev]

So is a new chain needed? Did someone repair the chain at one time??

 

[buickmike]

I have yet to throw a skip tooth chain away. And it goes back over 25 years. I added links to the chain and 20 years ago. I had a motorcycle chainbreak and better vision. Now I'm squinting and use a different chain tool meant for smaller Links. Still got a couple chains left and I'm gonna try to flip gear over for better alignment. Got the disc alignment. Tool so no problem there but gonna have to use stronger glasses.

 

[ricobike]

I just had this problem on a modern huffy. When I spun the crank I noticed that the chain ring was moving in concentric circles. I ended up just replacing the whole crappy chinese bottom bracket components with 60's Schwinn components and that solved the issue. I'm thinking either the crank was bent somehow, or the bearings weren't fitting properly causing the runout. I'll never know now because I threw it all in the garbage.

Edit: I should mention that some runout is always there. You should tension the chain at it's highest point. In my case, I had it as tight as it could be at the highest point and the chain was still going too slack at the lowest point and jumping the rear sprocket.

 

[buickmike]

Replaced chain and flipped rear gear over and took it on a 30° night. When I got back took everything apart. The rear can't be reversed cause some teeth are leaning forward and it was cracked at gap. Gonna put new hub and look at Bendix type driver. This my first roadmaster won't take Schwinn cups. + had trouble using diff crank cus they wouldn't even go in BB. Then TPI. 24 up to Schwinn 28. Had me damaging threads on only crank I did have. I I'm gonna keep tryin tho

 

[tryder]

I've got one of those bikes as you turn the crank alternates chain tension too tight then too loose. I tweeked the chain wheel for lateral r.unout and observed out of round runout not perfect but OK. I have replaced BB cups with generic cups that had to be shimmed. And spun wheel and occasionally while spinning gear will orbit like maybe axle isn't straight. But wheel spins freely and no side to side play. Once I remove guard - chain etc. Ill be full of grease+ no turning back. Any thing else I can check before its all in pieces

Do you have "It's easy to Fix your Bike" by John W MacFarlane? There is a method suggested in there that requires using a piece of wood and a hammer that makes me go "eek!" but you may already have tried that.

 

[buickmike]

This method setting up everything. As chain goes tight then smack ring in opposite direction. No I've never tried that. I usually upgrade to Schwinn stuff. I built up the 36 roadmaster when I couldn't get free spin on BB put Schwinn stuff in and cured it. Thanks for idea. Books are hard to find around here. Have to visit mall 25+ miles.

 

[PCHiggin]

I had the same problem with a 16” Ross and a 16” Sting-Ray Pixie I fixed up for my Grandchildren. The main problem on the Ross was a bent axle. The Pixie had a bent crank and sprocket. I guess it happened years ago when my children rode them.The binding trashed/stretched the chain and hid the problem until I recently overhauled and reassembled everything.