Has anyone ever had an issue when cold-setting a tweaked frame where it wants to creep back out of line again? I had a frame that was probably tweaked by a car/garage hit* which pushed the rear triangle out about 3/4". I bent it back to straight but after I rode it the frame tended to want to return to where it was in the bent position.

I'm trying it again but this time over-bent it a tiny bit and then brought it back into alignment. I'm hoping it stays this time. It's a beautiful frame with excellent paint built by the Dutch Company Juncker Bicycle Works which after a few buy-outs and mergers is now the people who make Gazelle bikes. I'd love to be able to save it instead of just harvesting the bike for parts.

*the rear wheel was poorly rebuilt by some home mechanic who used all different sized spokes on a replacement rim and before I rebuilt it the hop was nearly 1 INCH! It took me a few minutes to figure out what was going on there.

Never heard of that happening, but...

You may want to post your query to the BF Framebuilders' forum also. There's some VERY heavy-duty expertise over there.

SP
Bend, OR

3/4 inch out? Stop trying to bend it yourself, and take it to someone with the right tools.

After the initial spring-back it won't move any more unless pushed out again. Depending on the level of injury, it may be pushed out later pretty easily.

I think this is pretty much the same argument people gave the Wright brothers.

This is what has been my experience up until this point. But this particular frame seems to "remember" the un-straight position. There is no damage that I can see to any of the lugs or brazes. It just seems to want to curl up like a banana. I was wondering if anyone has ever seen this before. I wasn't aware of straightening frames being such a big deal and I know I'm not the only "non-professional" who knows how to measure a frame and bend stuff back carefully without causing more damage (first do no harm). It really isn't that hard.

I bed pipe for a living as an electrician. I've seen my share of springback but this is a type of "memory" that doesn't seem to match anything I've encountered before.

Didn't I tell you the exact same thing happened with my orange Norman? I went to a lot of effort to straighten the frame, using some big bar clamps and 4x4 timber. Rode straight as an arrow afterwards. But now, months later, the frame tracks to the side again. Nothing else has changed. It really feels like the steel sprang back to where it had been before I straightened it! Well, mebbe not all the way back to where it had been, but part of the way.

I think part of it is that I'm just a big fat-ahrsed dude and this is a little 19" frame meant for girls. Perhaps that could have something to do with it.

After over bending it and then bending it back it is holding steady. I ran over some really tough terrain -some of the worst striated pre-paving pot-hole strewn tarmac Humbolt Park has to offer and it is is holding steady. Even popped off of a few curbs. It is OK. Second time is a charm.

I got a new fork in today from Niagara for one of my other builds and tested out my fork-measuring jig and it seems that either my calibration is off 1/16" or the fork came off 1/16" -how close do those cheap SunLite forks come to perfectly true? is 1/16" error within what one can expect for them? It could be that the fork is off 1/32" and my jig is off 1/32" and we are adding up errors. YEAH -that's it...

So the fork is pretty straight now and the rear triangle is pretty straight and bike rides straight so I'm happy. What is there not to like? What a way to spend a day.

This frame wasn't built with heat treated tubing, was it?

-Kurt

Ride it and if rides ok then all is well but if you keep having to bend it you will be apt to have metal fatigue problem.

When you bend a steel tube that much it makes it more susceptible to fatigue failure which means it can fail at a much lesser stress amount that would have been perfectly acceptable had it not been bent.

I don't know -I was wondering if something like that was the case. I'm not 100% sure of the date of this bike. It looks SOOOOOOOO clean and sparkly it just doesn't look like a 1970-ish bike. The maker was Juncker Bicycle Works which eventually became or was bought out by the company that builds Gazelles now. The paint and lugwork are about 2 orders of magnitude better than the 70's Raleighs and even the 50s & 60's. It was ridden very little before whatever happened to it. With the original seat I can see why the lady who owned it didn't want to ride it. It has to be the single-most uncomfortable seat I have ever encountered in 40 years of riding bicycles. It's just a squared-off metal stamped block with sharp corners at the edge and just vinyl over it.

The rest of the bike is really nice except for the fender stays that were run to the axles instead of the dropout eyes. I didn't know anyone did this before the K-mart bikes.

The hub is a Styria-made Sears-branded AW. It's dated at 64. It's amazing if the bike is actually this old. The rear wheel was rebuilt BADLY and the rear rim does not match the front. The rim was OK, but the guy who rebuilt it put all sorts of different length spokes in there and just left them. Runout was fine but hop was amazingly bad. I think it got hit and messed up around the same time it stopped being ridden. It spent the next few decades inside a dry garage above the rafters. It was in pretty good shape other than the tweaked frame and goofy back wheel. Even the rubber looked almost new with little dry-rot. The tubes were amazing super-thick monsters with threaded stems. The Dutch know how to build a heavy-duty bike.

I think it's all in your minds. Steel just doesn't do that.

I need to stop dropping acid while I am straightening frames!

You need to over bend it back.

Sears did not sell hubs or wheels; they sold bicycles. All the evidence indicates your rear wheel began its career as part of a Sears bike and was later swapped into the Flying Jet.

I have heard from other sources that some European-market bikes were built new with the Sears-branded hubs as the Styria plant often made many more of them than Sears needed/required some years.

I could be wrong.

If everyone followed that kind of advice, nobody would ever learn how to do anything.

If you think you cannot do something, you are probably right.
If you think you can do (that same) something, you are probably right.

Git 'R done!

Yeah, well, so could I.

I've seen a lot of mismatched wheels, and have learned it makes the most sense to accept the easiest explanation. The bike shop I worked at in the early 80's had a fleet of rental bikes that were all at the end of their useful lives. Maintaining them was to some degree a game of musical chairs with the wheels, because it was easier/cheaper to switch wheels than fix flat tires or other ills.

My orange Norman looked every bit like an early 50's machine, with a Dunlop front rim, ancient Wrights saddle, oil port on the BB, and Sturmey Archer "3 or 4 Speed" trigger. But the AW was dated 1970 and it was laced to a Sturmey Archer rim. Conclusion: rear wheel wasn't original.

I have an Armstrong that came to me with a 28" front wheel and a 26" rear wheel, TCW-III hub dated 1965. Conclusion: rear wheel wasn't original.

And so on. Once upon a time mechanics used to rebuild wheels; then they discovered they could do less work and charge more for a new wheel. So they did. In your case, since the rims don't match, I doubt the Sears hub is original; but what do I know!

I'd say you just need to stress-relieve that frame...you know, like spokes when you're building a wheel.

I have seen odd stuff. A guy crashed a nice light frame on the track, Head tube no longer parallel to the seat tube. Yank the fork, and no amount of persuasion got it to move, in frustration the mechanic pushed it even more out of alignment and Whang! with a noise like that even and resonance vibration afterward, it went back straight. I would not want to repeat that, but funny things happen. Had it been on a lesser bike, I would have suspected stresses built into the structure at work, who knows.