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Old 09-21-06, 09:51 PM   #1
mihlbach
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bent steel fork

I just acquired a late 70s Motobecane Grand Jubile....the frame is in really nice condition, but the left fork blade is bent inward and forward about an inch or so. Would it be safe to somehow bend the fork blade back into position..or is this fork basically thrashed?
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Old 09-22-06, 05:02 AM   #2
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Originally Posted by mihlbach
I just acquired a late 70s Motobecane Grand Jubile....the frame is in really nice condition, but the left fork blade is bent inward and forward about an inch or so. Would it be safe to somehow bend the fork blade back into position..or is this fork basically thrashed?
There was a thread about this kind of thing a week ago, a fork that has been bent and then bent back, has a much higher likelyhood of breaking, and a broken fork will cause a face plant.
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Old 09-22-06, 06:15 AM   #3
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The great thing about a steel frame is that it can be bent and straightened again. The fork blade starts out as a straight tube; it is cold rolled into a taper. After which the frame builder cold bends the fork blade to a curve. So if it gets bent again by accident it can be safely bent back into alignment providing the tube is not dented, kinked, or rippled in any way.

It needs to be done by someone who has the tools and know-how to do it correctly and check the alignment. A good bike store of framebuilder could handle it; but it cannot be done over and over indefinitely; once is usually enough.
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Old 09-22-06, 08:44 AM   #4
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I don't know, would you trust your face with a rebent fork? Especially one that you haven't seen the condition of and don't know the history of?

If the fork is bent, are you sure the frame is not too? (food for thought).
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Old 09-22-06, 08:51 AM   #5
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The frame looks OK to me, but the fork is obviously bent, although the fork tubes are not dented or kinked in any way. The paint isn't even scratched, nor is any other part of the bike damaged. It doesn't look like it was crashed. I bought it on ebay and the posted photos show the bike fully assembled, so clearly the fork was not bent then. Now its impossible to even install the front wheel. I don't think it was packaged very well. There were no plastic thingys stuck between the fork dropouts to prevent the fork from bending, and I think it just got crushed sometime before or during shipping. Whatever happened, the frame fared much better because the rear spacing is still correct. (i.e. the stays were not bent)
It looks to me like the fork could be bent back, but I'm just not sure if I would feel safe riding on that fork. The frame and fork are intended for a fixed gear commuter. I would'nt want to have my fork snap while pedaling down a hill at 140 rpm. I know that cold setting the spacing of a steel frame is no big deal, but I'm not sure if re-cold setting a fork would be a very wise thing to do. I'm tempted to though...because its going to be tough to find another fork.

Last edited by mihlbach; 09-22-06 at 09:03 AM.
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Old 09-22-06, 09:07 AM   #6
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maybe you can get the seller to spring for a new fork. I doubt the carrier will give you money
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Old 09-22-06, 09:36 AM   #7
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maybe you can get the seller to spring for a new fork. I doubt the carrier will give you money
thats what I'm hoping for
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Old 09-22-06, 09:39 AM   #8
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Quote:
Originally Posted by mihlbach
the left fork blade is bent inward and forward about an inch or so.
That's a lot of bend! If it was my bike, and I was planning to ride it, I'd replace the fork.
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Old 09-22-06, 08:17 PM   #9
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This is just a follow-up to my bent fork. The left blade was displaced forward and laterally, probably not by an inch as I had suggested earlier...probaby more like half an inch. Anyway, it still looked pretty dramatic. I got home this evening and attempted to unbend the fork. First I forced the left blade laterally until the spacing was again close to 100mm...then I pulled it backwards until it was reasonably close to its original position. The second part was tougher, but I was surpised to find that I could actually bend it with my bare hands, although I had to put my whole body into it. So now I'm riding around on it and it looks and feels OK. I think I'll just be gentle with it until I find another fork.
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