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Bent fork blade

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Bent fork blade

Old 06-24-18, 09:24 PM
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Narhay
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Bent fork blade



Is this fixable at your average bike mechanic's home?
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Old 06-24-18, 09:43 PM
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I have the Park Fork alignment gauge and the other bending tool (forget what it is called), this would be repairable in my opinion for a mechanic with those basic frame tools.
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Old 06-24-18, 10:23 PM
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Not at your average bike mechanic's home. But you've got the right tools there for a good first try.

Forks take more jigs, fixtures and persuaders than frames, it would seem. IF you can firmly clamp the steerer with some frame blocks, see if you can persuade the dropouts to be parallel and concentric. Once you do that, put a wheel in. Is it centered? If yes, you're done. If no, then the distance between the center of the fork crown and the center of each dropout is different. The fix for that requires adding a slight amount of rake (offset) to the blade which has the wheel center farthest off. This effectively shortens the blade, lessening the distance between the center of the fork crown and dropout, and pulls it centered. Sometimes this takes a few iterations.

The amount of rake you add is typically very slight.

I've been doing this quite a bite lately, locals have been descending on Atelier Gugie a lot this year. Norther Cycles will do this repair as well.
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Old 06-25-18, 07:17 AM
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Thanks very much. I'll give it a go and see what I can do. Seems to be less than 1cm. I noticed it when putting the frame on the ground it wanted to turn to one side.

I will have to decide which way I want to bend it...one forward or the other back. I will have to play with the wheel to see if I can get it centered.

Any hardware store tools I can use as a persuader?
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Old 06-25-18, 09:21 AM
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Those park tool alignment gauges will give you plenty of leverage. I find if I hold the fork blade with one hand and the tool with the other, I can exert enough force to bend the fork dropout in all kinds of ways.
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Old 06-25-18, 10:06 AM
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Yes, this can be achieved by a home mechanic. The equivalent of a Park FFS-1 Frame & Fork fork straightener can be be easily duplicated using a hockey stick shaft and a U-bolt with a couple plate washers and nuts. The only other things you need area vice with a couple pieces of hard wood to hold the fork, and a flat surface, such as a pane of glass, to act as an alignment surface. The proper tools expedite the procedure, which is important in a shop setting, but the same results can be achieved with simple home made tools.

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Old 06-25-18, 10:18 AM
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If non parallel tips are the only issue,
and not the blades being individually bent out of alignment..





...
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Old 06-25-18, 10:58 AM
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Personally I would fix that myself but if you are not comfortable doing yourself and you want someone local go to Biseagal | Toronto based bicycle repair and restoration shop. They are on Carlaw in the east end. They do frame repairs and will have the necessary tools and know how to fix it.
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Old 06-25-18, 12:04 PM
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Originally Posted by nlerner View Post
Those park tool alignment gauges will give you plenty of leverage. I find if I hold the fork blade with one hand and the tool with the other, I can exert enough force to bend the fork dropout in all kinds of ways.
+1.
Just about anything you grab the steerer with and it'll spin if you try to wrench a CrMo strength fork blade. Sometimes I'll angle the fork down so I can hold both tools with each hand and use my knee as a leverage.
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Old 06-25-18, 01:19 PM
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Originally Posted by fietsbob View Post
If non parallel tips are the only issue,
and not the blades being individually bent out of alignment..
Bob makes an important point: If you don't know whether the dropouts are twisted (dropout alignment tool) or whether one blade is bent (fork bending tool), you might "fix" the wrong problem and end up with a twisted fork that while act oddly as it flexes.


I would suggest getting a better idea what's wrong before bending anything. Place straightedge or pipe on the blades near the crown and another near the dropouts. Are they parallel?
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