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Framebuilders Thinking about a custom frame? Lugged vs Fillet Brazed. Different Frame materials? Newvex or Pacenti Lugs? why get a custom Road, Mountain, or Track Frame? Got a question about framebuilding? Lets discuss framebuilding at it's finest.

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Old 11-11-09, 03:49 PM   #1
Road Fan
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Straighten a UO-8 steer tube?

I guess I should have asked here first. I just got a UO-8 because I wanted to see how it's unusual front end geometry feels. Repairing the headset I found the steer tube is bent, enough that a good headset will show some binding. I know it is possible to replace a steer tube, but this is a CHEEP project. What do you guys think about straightening it? The bend is about 2 degrees max, not near the fork crown, and there is no sign of fork blade or frame damage or stress. The direction of the bend is the opposite of what I'd expect from a frontal collision anyway. The steel is in the low carbon/high carbon family, not 531 or CrMo.

What y'all think? Might it be safe? Should it be done with a torch? Any experience with such a repair?

I really want to keep the dimensions of the OEM fork. It has around 7 cm of rake, a very tight old-fashioned French bend at the end, and it's loooong to accommodate 32+ mm 27 inch tires with a fender. I doubt a modern replacement exists.
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Old 11-11-09, 10:11 PM   #2
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I can't imagine that ending well. Steerers have been known to break. If the fork isn't bent, but the steerer is, that doesn't say good things about a repaired version. And finding a french steerer is not impossible, but probably not cheap.
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Old 11-12-09, 01:22 PM   #3
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Even with a 2 degree bend, and no large kink at the bend? Surprised rather soft steel is so fragile - this isn't CrMo, MnMo, or something air-hardened, and its really not aluminum.

I do understand the greater risk of injury in case of failure of this tube.
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Old 11-12-09, 06:45 PM   #4
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Even with a 2 degree bend, and no large kink at the bend? Surprised rather soft steel is so fragile - this isn't CrMo, MnMo, or something air-hardened, and its really not aluminum.

I do understand the greater risk of injury in case of failure of this tube.
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Old 11-12-09, 10:32 PM   #5
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While I appreciate volunteering opinions, I thought I was explicitly looking for those with experience in repairing frames.

I can theorize better than most. That isn't what I needed.

Thanks anyway.
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Old 11-13-09, 01:31 AM   #6
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Go ahead straighten it.
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Old 11-14-09, 01:08 PM   #7
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If my powers of deduction are up to snuff, he had a bike shop bend it and they ovalized the threads.

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I can't imagine that ending well.
Just because we post on BF doesn't mean we don't know what we are talking about.
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Old 11-14-09, 09:13 PM   #8
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Good work; I saw you there. Yes, they ovalized the end of the thread area, and I managed to squeeze it back round, at least round enough to insert the right stem and thread the headset parts on. I used a 14 inch channel-lock and a pair of wood buffers. It took about 15 squeezes, in several different directions. No added thread damage.

Plan is to assemble the fork to the frame, finish reassembling the bike, and do some smooth-road test rides, just a few hours. That will be enough to tell me if I like the bike and geometry, which is the main point of this whole project. If I do like the geometry, I'll get a replacement.

Update 1: The headset install feels pretty darn good! It adjusted correctly and spins freely 360 degrees.

Last edited by Road Fan; 11-16-09 at 05:25 PM.
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