Bent frame!

[hatake]

Yes I built a true wheel and is dished equally

This, no matter how I position my rear wheel, rear tire butts against right seat stay. Chain stay alignment is nicely balanced, so I concluded that either left rear section is pushed up, or right seat stay is way too low. Perhaps endured a bad landing of some sort... Now welds are pretty weak on this department store AMF bike, so I'm not exactly eager to sandwich chain stays horizontally with 2x4 and use the force. Cantilevers are separated from the downtube already - well maybe that's good in this case.

What would you boys do if you were in my situation? How would you, basically, push up the whole right rear triangle without further separating welds?

 

[Wildcat]

An AMF frame from the 60's!

I've had a few frames that needed some tweaking to line up the rear wheel. Be sure to do just a little adjustment at a time. First, I would check the alignment of the seat stays and chain stays. They should show signs of damage if they are bent, that will show you which side needs straightening or both if it's bad. I would do a little bending, then put the wheel back in with chain on the sprockets to see how it's coming. If there's no progress with a little work, I would stop and take it to the local bike shop to see if they can figure it out. They will probably say you need to buy a bike from them. However, I wouldn't give up on this frame, it doesn't seem that bad. I had a steel rod I would slide in the dropouts and then use it to move the dropouts until it was right. It will take some patience but I think it can be straightened.

 

[Walker]

I know I've posted up this method before, but here goes.....

strip the frame incl. the cranks, clamp the bottom bracket in a bench vise.

make up a piece of string with a loop on one end, hook this around one drop out, loop the string around the headtube and pull it back to the other drop out. tie in a rubber band so you can tension the string and make it hands free.

now you can measure from the string to the seat tube. this will tell you which way the rear end it bent and how much.

progressively bend each stay, one at a time, keeping the spacing correct, until you have equal distance from the string to the seat tube on each side. Go easy, a little goes a long way

your frame is mild steel. no special tools are necessary.

Done.

 

[hatake]

Little by little sounds like a plan. Interesting way to measure, sounds like a field alignment check they do on rally stages. I'll try that tomorrow! Thanks guys. I have another better aligned frame but I don't want to give up this easily

 

[OUTLAW]

I'd cut it up an make a BURRITO out of it. but then that's just me.lol.

Outlaw 8)

 

[hatake]

I finally had a guts to apply some force to the frame tonight. Fiddled with 2x4 for a while to visualize how the frame should be corrected. Wrapped headtube and BB shell (really didn't need to). Pushed gently for a couple of minutes first.

Didn't do a ...... thing. So I pulled slowly for a while. Not much improvements. Well I said the heck and jumped on, stumped, hopped, and jiggled

30 min later, it finally looked a little better, although some paint flaked off If I look at the frame closely, seat stays are really not symmetrical. Oh well.

Before:

Now I can proceed with the rest of the build. I have build a pair of truss rods with a home made brace that actually look vintage. Can't wait for this weekend!