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Old 11-21-11, 07:06 PM   #1
goatalope
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Spacers above Crown Race?

I have a 1997 Scott Vail MTB frame (cromo, threadless headset). Back in 97 it came with a suspension fork thats since died. I have a rigid fork (chromo) off another bike I'd like to put on it; however, the rigid fork is not suspension corrected. I'm wondering if there's a way to put a spacer or two under the crown race to somewhat correct for the suspension? Any structure issues?

I have plenty of steerer tube above the head tube, so thats not an issue.
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Old 11-21-11, 07:14 PM   #2
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Why do you need to? a frame from 1997 doesn't need suspension corrected forks, as most forks back then were of a max 80mm travel (that was long trave then), and that dosen't need any correcting. Besides that, you can't put a spacer above the crown race, as it would interfere with the bearings.
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Old 11-21-11, 08:02 PM   #3
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You also can't put a spacer under the crown race. The crown race is a press fit on a slightly larger diameter section of the steerer and a spacer would hold it above the proper location.
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Old 11-21-11, 08:13 PM   #4
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A machined spacer if accurately made, would go under the crown race..

on top of the crown race seat..
some benefit of a cartridge sealed bearing race on the bottom, at least..


But typically suspension correction is making the fork blades longer.
consider getting the fork made for the frame, instead.

Last edited by fietsbob; 11-21-11 at 08:20 PM.
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Old 11-21-11, 08:37 PM   #5
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Quote:
Originally Posted by jimc101 View Post
Why do you need to? a frame from 1997 doesn't need suspension corrected forks, as most forks back then were of a max 80mm travel (that was long trave then), and that dosen't need any correcting. Besides that, you can't put a spacer above the crown race, as it would interfere with the bearings.
+1

Suspension travel was much less back then. Unless this is a serious downhill bike even a non-corrected rigid fork should work just fine. How much of a difference is there in the axle-to-crown distance? Like you, I've read that making these changes can seriously mess up the handling. But having personally done this twice, it's really not a big deal. With a shorter fork your handling will be slightly "faster" and twitchier, but I doubt it will be adversely affected.

Your question about the spacers above the crown race was covered before. Conclusion: dangerous/impossible.
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Old 11-21-11, 09:38 PM   #6
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Originally Posted by fietsbob View Post
A machined spacer if accurately made, would go under the crown race..

on top of the crown race seat..
some benefit of a cartridge sealed bearing race on the bottom, at least...
The spacer would have to mimic the diameter of the crown race seat at the point where the crown race is actually installed.
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Old 11-21-11, 09:45 PM   #7
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My 1997 KHS is pretty sprightly with a 390mm ATC fork, I kinda like that in a way but it can be a bit of a handful that some folks might not care for. A 410 would've been about right. 440 woulda been a little too tall and slack for my tastes. Start by measuring your axle-to-crown (ATC) If your fork is around 410 I'd just roll with that fork.

If you feel you need a longer fork but don't want to replace yours, the thing you're looking for is a Head Tube Extender. Eighth Inch makes some and they suggest installation with a headset press. You'll have to pop out your bottom cup, press in the extender, then press your bottom cup into that. Actually they suggest a shop do the work.

http://www.eighthinch.com/headtube_extenders.html

Last edited by LesterOfPuppets; 11-21-11 at 09:54 PM.
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