splukonik

I have a 1951 Schwinn 26" Straight Bar Frame that I have designs on rebuilding. Upon inspection I have found that the front (forward from the seat tube) and rear are not aligned. It appears that the kickstand housing may have been rewelded at some point in time as the welds do not seem to be the quality of Schwinn and are also not braized on with brass like I think they should be. Does anyone know a good way to determine where the point on the frame would be to attempt to straighten it? Are there any companies that are known to do this? Or maybe I should forego all this and look for another frame? I really wanted to bring this one back to life but I can't sink a fortune into it. Any input will be appreciated. Thanks and happy trails!!

Scooper

The bike was likely crashed sometime in its history knocking it out of alignment, and somebody without the proper tools and skills probably tried to straighten it.

Frank Schwinn developed the cantilever frame specifically to keep the seat tube and head tube aligned in the same plane as dynamic forces tend to twist them out of plane, and if I were going to give new life to an old Schwinn balloon tired bike, I'd look for a straight, cantilever frame for the rebuild. Used cantilever frames aren't that expensive and have a well earned reputation for taking lots of abuse without damage.

sailorbenjamin

Here's an article on bending frames and if you scroll down a bit it'll tell you how to check the alignment. Basically, you run a string from one rear dropout to the head tube and back to the other. The seat tube should be in the exact middle of the resulting triangle. Better to look at the picture here;
https://sheldonbrown.com/frame-spacing.html

sailorbenjamin

My 1950 Schwinn straightbar, btw;

splukonik

Thanks for the quick replies! I used the info at Sheldon Brown's (RIP) site and got it straightened out pretty good I think. I'm gonna do a complete mock assembly before I even prime the frame to make sure it rides ok before I start shoveling money into it.

Now my next question: Are New Departure Rear Axle Threads different from Bendix Rear Axle Threads? I'll post a new thread...or is it thread a new post??

sailorbenjamin

For more info, you might also try www.thecabe.com and www.ratrodbikes.com.