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Discussion Starter · #1 ·
Hi all. I've built my own bike and am comfortable wrenching, but I've got an issue that's baffling me.

I have a 'low-end' aluminum frame with IS cups. My first cane creek headset lasted 1 year and disintegrated last week. I'm sure it failed because I have way too much tension in the headset because I've never been able to get it sufficiently 'tight'. I can tighten it to where I would on my non-integrated mtn bike and when I sprint or snap the brakes I can feel the headset shift (knock). To get it tight enough to not shift it causes so much friction that the bike is almost unrideable. I originally attributed the shifting to poor tolerances in the headset cups...the vertical sides aren't all that tight on the bearing, but there really shouldn't be any contact except with the 45deg surfaces.

Now what I'm wondering is if my long headtube (220mm) and lightweight/noodly fork (deda blackmagic) are causing enough angular deviation to rock/slide the bearings in the cups?

Anybody got any insight? Sorry for the long post...wanted to get all the details out there.

Thanks,
BAE
 

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info...

A headset bearings should never be too tight and still knock.

Are you certain that there is a gap between the top of the steering tube and the top of the stem or the spacer on top of the stem? This is a must. A misinstalled compression plug could also be a problem. The FSA type that applies pressure with a threaded top cap, not a top cap bolt, can be installed so it bottoms out on the expanding portion without applying enough tension to the bearings.

If you have ridden the frame extensively with the bearings loose (knocking) then you may have damaged the lower bearing seat. Most aluminum frames have no removeable bearing seats, so the seats may need to be recut. Park sells tools to do this, but finding a shop that has them might be tough.

Normally, when the top cap is tightened, you would apply enough pressure to cause the fork to drag a little as it is turned, then loosen it just slightly, to eliminate the drag. If the bearings are too tight, the fork will not readily self-center after a turn, but the bearings will not knock.
 

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Discussion Starter · #3 ·
They *shouldn't* knock. To keep mine from knocking in all conditions I've got to tighten it to the point that the drag is so bad I can't ride hands off. Compression plug is in place and I've got a 10mm spacer on top of the stem. When JRA there is no play, it only happens when under braking or sprinting out of the saddle. I figure those events only happen when there's a lot of moment in the fork.

I spoke to Cane Creek tech support a little while ago, and it sounds like my headtube cuts are within spec. They were baffled as well...trying to decide what the best course of action is. A known 'stiff' fork like an Alpha Q is approaching CAAD9 frameset prices...
 

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Discussion Starter · #4 ·
Embarrassing, but a followup:

Installation error, of course. Had the crown race and 'centering ring' in each other's spots. Doh!

Thanks for the response. ; )
 
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