Brinelling
I searched threads and found this term referring to a fork self centering. A friend has a '82 Peugeot that does that and he claims it is designed that way. I have had bikes do it and have serviced the bearings to correct it.
I don't want to tell him he is wrong without being sure. Does he need to service the headset or not? Thanks. |
Your friend is absolutely wrong. It is not "designed that way", it is a defect and should be repaired.
"Brinelling" is a misnomer but it's used to describe the pockmarking of the headset races (usually the lower race) due to impact, lube breakdown and wear. The pockmarks align with the bearing balls and cause what is called "index steering" or the self-centering you mentioned. It interferers with the proper steering of the bike and in serious cases can be dangerous. A quick and temporary fix is to replace caged balls with loose balls. That requires one or two more balls per race and the pockmarks no longer line up with the balls. The proper fix is to replace the headset with a new one followed by proper adjustment and lubrication to keep it from happening again. . |
You can also remove the lower race that's installed in the head tube, rotate it slightly and reinstall.
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on occasion, i've been able to purchase a new bottom race for a few dollars...
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Keep in mind that today's ultra-stiff cable housings, especially when installed on the short side, can contribute to fork centering. If the bike in question has under-tape cable routing, the cables are just long enough, and the housings are very stiff, you may want to try disconnecting all the cables from the derailleurs and brakes and retesting the effect. No sense redoing the head set if that is not the problem.
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Originally Posted by cny-bikeman
(Post 16519332)
You can also remove the lower race that's installed in the head tube, rotate it slightly and reinstall.
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Sounds like your friend may have been and old customer of FBinNY! I found this last night while searching this topic myself:
When I was in retail eons ago, this was a common issue affecting all good road bikes, and we learned that we could still ride even with really badly fretted headsets. But many people would be concerned so I started the rumor that Campy made special Cyclocross headsets that indexed this way so the front wheel wouldn't swing around when you carried the bike up embankments. That worked fine until someone walked in one day and insisted on buying a cyclocross headset. |
Originally Posted by AB@WDW
(Post 16519398)
Sounds like your friend may have been and old customer of FBinNY! I found this last night while searching this topic myself:-Andy
Thanks for the replies. |
Originally Posted by HillRider
(Post 16519397)
That's another only temporary fix and nearly as much work as replacing the damaged race with a good one.
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Originally Posted by a77impala
(Post 16519416)
You may be right, he insisted it was designed that way. I don't really want to tell him he is wrong!
Thanks for the replies. Temporary can be a long time, and finding a compatible lower race can take a long time as well. |
Originally Posted by HillRider
(Post 16519397)
That's another only temporary fix and nearly as much work as replacing the damaged race with a good one.
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That is a good point, I had completely forgotten that!
cnybikeman's posting above has merit because headsets for an early 1980's French bike are going to difficult to find.[/QUOTE] |
Originally Posted by a77impala
(Post 16519416)
You may be right, he insisted it was designed that way. I don't really want to tell him he is wrong!
Thanks for the replies. In my experience in retail, nobody ever brought in an index headset complaining of handling problems. It was always noticed while walking or working on the bike. The fact that it posed no riding problems is what made my XC gag credible. IMO, the OP should ride the bike, and if it rides OK, not worry about it yet. It will get worse over time, and at some point he can decide it's time to replace it. |
Another temporary fix is to swap the upper and lower cups and add new bearings, caged or not. bk
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Originally Posted by bkaapcke
(Post 16519817)
Another temporary fix is to swap the upper and lower cups and add new bearings, caged or not. bk
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I'm confused. I usually tighten my headset adjuster ring tight enough to where the steerer locks forward. This is damaged? or is this only bad when it becomes this way naturally?
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Originally Posted by Mr_Wrench
(Post 16521594)
I'm confused. I usually tighten my headset adjuster ring tight enough to where the steerer locks forward. This is damaged? or is this only bad when it becomes this way naturally?
The traditional rule for headset tightening is to the point where there's no discernible play when the bike is rocked forward against a locked front brake. Old townies sometimes have a spring between fork and downtube to help keep the front wheel aligned (during handling other than riding I presume). Many mechanics keep either a bungee cord or a strap from a pedal clip handy to secure the front wheel of a bike that gets hoisted onto a workstand. I think I've seen a properly engineered steering damper on a DH bike once. But again, that'll give a smooth motion across the arc. Now, "bad" is a tricky word in these circumstances. Is it meant to be like that - No. Will it cause the bike to self-destruct, or you to lose control in a critical moment - hugely unlikely. Revise your headset adjustment parameters. Ride and be happy. Replace when troubled by it. |
Originally Posted by dabac
(Post 16521615)
Steering is supposed to be a smooth motion across the arc. Indexing is always a bug and not a feature.
The traditional rule for headset tightening is to the point where there's no discernible play when the bike is rocked forward against a locked front brake. Old townies sometimes have a spring between fork and downtube to help keep the front wheel aligned (during handling other than riding I presume). Many mechanics keep either a bungee cord or a strap from a pedal clip handy to secure the front wheel of a bike that gets hoisted onto a workstand. I think I've seen a properly engineered steering damper on a DH bike once. But again, that'll give a smooth motion across the arc. Now, "bad" is a tricky word in these circumstances. Is it meant to be like that - No. Will it cause the bike to self-destruct, or you to lose control in a critical moment - hugely unlikely. Revise your headset adjustment parameters. Ride and be happy. Replace when troubled by it. |
Originally Posted by Mr_Wrench
(Post 16521594)
I'm confused. I usually tighten my headset adjuster ring tight enough to where the steerer locks forward. This is damaged? or is this only bad when it becomes this way naturally?
:) |
In all fairness, years ago my local bike shop gave it to me that way. Good to know the "right way" but I'll keep doing it the "wrong way" on my bikes. Sure is an easy way to pedal without hands.
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Originally Posted by Mr_Wrench
(Post 16527021)
In all fairness, years ago my local bike shop gave it to me that way. Good to know the "right way" but I'll keep doing it the "wrong way" on my bikes. Sure is an easy way to pedal without hands.
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It seems to me that "locking" a bike's steering at all, whether forward or any other position, would hinder hands-free riding, not help it. When riding hands-free, you're constantly making small steering corrections by shifting your weight and you would want the headset to turn freely to allow it. It's the steering geometry that'll keep steering roughly centered, not friction in the headset resisting turning forces.
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Originally Posted by Sixty Fiver
(Post 16524417)
Just where do they call you Mr ?
:) |
Originally Posted by SkyDog75
(Post 16527341)
It seems to me that "locking" a bike's steering at all, whether forward or any other position, would hinder hands-free riding, not help it. When riding hands-free, you're constantly making small steering corrections by shifting your weight and you would want the headset to turn freely to allow it. It's the steering geometry that'll keep steering roughly centered, not friction in the headset resisting turning forces.
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Jesus Christ.
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