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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 07-09-12, 11:43 PM   #1
gsus
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notched steering feel when turning the handlebar on stand (GMC Denali)

I just noticed that the handlebars don't glide smoothly from left to right or right to left on my 09 GMC Denali. They seem to settle into a spot every few degrees. Any ideas on why this may be and what options I may have?

Thanks!
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Old 07-09-12, 11:57 PM   #2
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It means your headset (the bearings that the fork turns on) is worn out. It prefers to settle into set positions because the ball bearings are finding little worn out dimples in the bearing surfaces to rest in.

You can go to an LBS and have them install a new headset, but the job will run in the neighborhood of 65$. Considering that this is a significant proportion of the bike's monetary value, you may be better off noticing that many other areas of the bike are also worn out and that its cheaper to just buy a new bike.
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Old 07-10-12, 06:28 AM   #3
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This probably occurred due to a poorly adjusted headset (either too tight or too loose).

If the bearings are in a retaining ring, you can replace them with loose balls. You will be able to fit more loose balls than are in the retaining ring so this will lessen the indexed steering effect since not all balls will be in the existing dimples.

You could also try to rotate very slightly the crown race on your fork to offset those dimples from the ones on the cone race in the top of the headtube. But this would require some special tools to pop off the crown race and re-seat it on the fork. I have never tried this so I don't know how effective it is.

Mild indexed steering isn't a big deal. My old MTB developed indexed steering and I rode it that way for at least 10 years before replacing the headset.
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Old 07-10-12, 03:01 PM   #4
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You can do nothing or you can remove, clean, and regrease, and everything will be fine again. You don't need to replace the headset.
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Old 07-10-12, 03:14 PM   #5
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I would not guarantee that at all. Gonzo Bob's post is accurate.
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Old 07-10-12, 04:47 PM   #6
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A typical headset that is adjusted too tight will do this. Or it could be that the headset races have worn or otherwise been damaged so that the race tracks are no longer smooth. Or it may have even cracked a race if you ride fairly extremely.

The only way to tell for sure is to pull off the stem, drop the fork out and clean then closely inspect the headset races and bearing balls. If everything checks out as OK then likely it was simply adjusted too tight. Re-grease and set the preload so that you lose any slop and then then go for just a hair more preload so that the races do not come loose when loaded. You want to feel a little preload drag but it should be smooth with no notchiness or cogging like feel.
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Old 07-10-12, 07:14 PM   #7
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Thank you for all of the helpful input. I just acquired this bike not too long ago and I've already replaced the bottom bracket, the wheels (with spares that I had from my GT road bike), the chain and crankset, and I've also replaced the annoying grip shifters... clearly, I don't mind getting my hands dirty. I was told by the PO that bike did sit out last winter (which is why I replaced the drivetrain).

With that said, I will disassemble the front steering hardware to see if there are any cracks or unsmooth race tracks. The notches don't really bother me much, but if it's something fixable I don't mind doing it.

Thanks again!
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