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Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

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Old 09-01-08, 12:34 PM   #1
singletracksSC
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bent head tube repair?

it's a steel frame that was likely bent during the painting process...the top of the head tube is bent in a little but enough to see with the naked eye. I'm hoping and assuming steel is easy to repair but I'm not sure if I should take it to a bike shop or a machinist or...anyone know how big a deal this is?

thanks.
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Old 09-01-08, 02:46 PM   #2
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Sounds like more of a dent than a bend. I would think that anyone skilled in automotive dent repair could easily fix the dent. Once they got it really close, you could add some extra insurance by having the head tube reamed back to a perfect circle.

Alternatively, you could just try to press the headset cups in and let them do the straightening. Chances are if the lead-in on the cups will allow them to get started, they'll press in and stay in just fine.

If you wanted to try something yourself, this might do the trick if it would fit: http://www.thetoolwarehouse.net/shop/LIS-32500.html
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Old 09-01-08, 03:58 PM   #3
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It could be a HUGE deal. I can't imagine bending a head tube under any but nearly catastrophic conditions.

We need pics!
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Old 09-01-08, 04:08 PM   #4
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Steel head tubes aren't all that thick. Dropping the frame or even turning and thumping it against something could produce a little kink in the lip.

If it's just barely visible and only over a small area I'd just forget it and press the cup into place. The cup will force it back and it won't be a big deal. If it's more than that you'll want to have it beaten back out and possibly squeeze and push the tube back to fully round.

If you want to coax it out anyway you can. Get a 2 foot length of heavy wall pipe that is a little smaller than the hole in the head tube. Insert it about 3/4 of the way and then pry it to the side to bend the dent back out until it's pretty close to true. Just bend it back. Don't try to stretch it out all the way. You'll likely need a few helpers to hold the frame down firmly while you do this. Pad it well with thick blankets or it'll be going back for fresh paint and a second ding....
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Old 09-01-08, 04:37 PM   #5
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blurry but gets the point across...seems like it'll be okay...
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Old 09-01-08, 04:41 PM   #6
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Rofl. Wow. It actually is bent, and not a dent. Oh yeah, make use of the macro mode on your camera if you have it.

Your pic is blurry as heck.
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Old 09-01-08, 05:05 PM   #7
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this one is a little clearer..thanks.
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Old 09-01-08, 06:21 PM   #8
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I think it'll be easy enough to coax back to roundness using a pipe or rod.

I sure hope you got a deal on the paint for all this trouble....

Depending on what you have for a setup you may find that it's easier to put the pipe or barstock into the vise and then just place the head tube over it and lever away using the rest of the frame to hold onto. That way you're not going to worry about it getting scratched.
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Old 09-01-08, 06:34 PM   #9
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Originally Posted by singletracksSC View Post
this one is a little clearer..thanks.
But now we can't see that you have a Brooks saddle on another bike.
Yes, that is not round.
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Old 09-01-08, 08:50 PM   #10
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Quote:
Originally Posted by singletracksSC View Post
it's a steel frame that was likely bent during the painting process...the top of the head tube is bent in a little but enough to see with the naked eye. I'm hoping and assuming steel is easy to repair but I'm not sure if I should take it to a bike shop or a machinist or...anyone know how big a deal this is?

thanks.
You should be able to repair this. Do you have a bike builder in your area? Best option to take it to a local builder. Second alternative would be to take it to an auto repair shop where they have the tools to effect a repair. They may have a conical tool they can tap down the head tube and get it into round so they can install the headset. Good luck
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Old 09-01-08, 09:21 PM   #11
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Find an old steel headset cup and slowly press it in. it should bring it back into round. Then ream and face the headtube
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Old 06-11-09, 03:18 PM   #12
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Wow, same deal on my recently acquired recumbent frame.



So you guys think this happened during the painting process?

Could a plumber possibly fix it? There's one kinda close by.

Failing that, would you really recommend an auto body shop over a regular bike shop?

Guy at my LBS is quite skilled, but unfortunately he's like thirteen unlucky miles away.

Update: Contacted the frame builder and he thinks it can be re-rounded, by a machinist, then it would have to be refaced.

D'oh!

Last edited by andychrist; 06-11-09 at 10:26 PM. Reason: Update
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Old 06-13-09, 05:36 PM   #13
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Hey, the auto mechanic was able to bang it back into shape pretty well with the conical tool they use on exhaust pipe. But it might still have to be reamed, hope my LBS can do that!
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