Headset with notched bearings
11-10-20, 02:18 PM
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Headset with notched bearings
I'm not sure if I should post this here or in the mechanics forum but I'll start here.
Background:
My '99 Litespeed has a Shimano HP-6500 headset that has developed quite a notching problem (1" headset with a quill stem). A few days ago I pulled the headset apart and took out the bearing cartridges. The HP-6500 doesn't have loose balls in the races of the headset, they have cartridges with the bearings in cages inside of them and you put the cartridges where the bearings normally would go. I took the cartridges apart to clean and re-grease and sure enough both cartridges had indentions where the balls seated into the races. To try to fix it I removed the old ball bearings and cages and repacked them with new 5/32"loose balls to fill in all the way around the circumference of the race and lots of grease. I put everything back together and it helped but I do still feel some roughness. I decided to order some replacement cartridges (expensive since they aren't being made anymore) and will put them in when they arrive.
So here's my question. When putting the headset back together, is it better to err on tightening the headset too tight or too loose? If I get it too tight, it seems like the balls would be more likely to seat themselves in one spot and accelerate creating indentions. If too loose, I'd guess that the bottom cartridge would take more load while I'm riding and thus accelerate creating indentions. Where's the happy medium? I have in my mind that I should tighten the headset up to where it just starts to become stiff to turn the fork and then back it off a little bit. Is that right or is there some other way to gauge?
--Brad
Background:
My '99 Litespeed has a Shimano HP-6500 headset that has developed quite a notching problem (1" headset with a quill stem). A few days ago I pulled the headset apart and took out the bearing cartridges. The HP-6500 doesn't have loose balls in the races of the headset, they have cartridges with the bearings in cages inside of them and you put the cartridges where the bearings normally would go. I took the cartridges apart to clean and re-grease and sure enough both cartridges had indentions where the balls seated into the races. To try to fix it I removed the old ball bearings and cages and repacked them with new 5/32"loose balls to fill in all the way around the circumference of the race and lots of grease. I put everything back together and it helped but I do still feel some roughness. I decided to order some replacement cartridges (expensive since they aren't being made anymore) and will put them in when they arrive.
So here's my question. When putting the headset back together, is it better to err on tightening the headset too tight or too loose? If I get it too tight, it seems like the balls would be more likely to seat themselves in one spot and accelerate creating indentions. If too loose, I'd guess that the bottom cartridge would take more load while I'm riding and thus accelerate creating indentions. Where's the happy medium? I have in my mind that I should tighten the headset up to where it just starts to become stiff to turn the fork and then back it off a little bit. Is that right or is there some other way to gauge?
--Brad
11-10-20, 03:05 PM
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Originally Posted by MidTNBrad
I'm not sure if I should post this here or in the mechanics forum but I'll start here.
Background:
My '99 Litespeed has a Shimano HP-6500 headset that has developed quite a notching problem (1" headset with a quill stem). A few days ago I pulled the headset apart and took out the bearing cartridges. The HP-6500 doesn't have loose balls in the races of the headset, they have cartridges with the bearings in cages inside of them and you put the cartridges where the bearings normally would go. I took the cartridges apart to clean and re-grease and sure enough both cartridges had indentions where the balls seated into the races. To try to fix it I removed the old ball bearings and cages and repacked them with new 5/32"loose balls to fill in all the way around the circumference of the race and lots of grease. I put everything back together and it helped but I do still feel some roughness. I decided to order some replacement cartridges (expensive since they aren't being made anymore) and will put them in when they arrive.
So here's my question. When putting the headset back together, is it better to err on tightening the headset too tight or too loose? If I get it too tight, it seems like the balls would be more likely to seat themselves in one spot and accelerate creating indentions. If too loose, I'd guess that the bottom cartridge would take more load while I'm riding and thus accelerate creating indentions. Where's the happy medium? I have in my mind that I should tighten the headset up to where it just starts to become stiff to turn the fork and then back it off a little bit. Is that right or is there some other way to gauge?
--Brad
Background:
My '99 Litespeed has a Shimano HP-6500 headset that has developed quite a notching problem (1" headset with a quill stem). A few days ago I pulled the headset apart and took out the bearing cartridges. The HP-6500 doesn't have loose balls in the races of the headset, they have cartridges with the bearings in cages inside of them and you put the cartridges where the bearings normally would go. I took the cartridges apart to clean and re-grease and sure enough both cartridges had indentions where the balls seated into the races. To try to fix it I removed the old ball bearings and cages and repacked them with new 5/32"loose balls to fill in all the way around the circumference of the race and lots of grease. I put everything back together and it helped but I do still feel some roughness. I decided to order some replacement cartridges (expensive since they aren't being made anymore) and will put them in when they arrive.
So here's my question. When putting the headset back together, is it better to err on tightening the headset too tight or too loose? If I get it too tight, it seems like the balls would be more likely to seat themselves in one spot and accelerate creating indentions. If too loose, I'd guess that the bottom cartridge would take more load while I'm riding and thus accelerate creating indentions. Where's the happy medium? I have in my mind that I should tighten the headset up to where it just starts to become stiff to turn the fork and then back it off a little bit. Is that right or is there some other way to gauge?
--Brad
And yes, that's the way to do it. The trick is knowing how much to back off, and being ready to undo and reposition things if after you lock the headset it's not right anymore.
Insert and tighten the quill before adjusting the headset.
11-11-20, 03:51 PM
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your fork crown race and lower cup need replacing at the least. your headset has what's known as "brinnelling".
b4 there was rockwell hardness testing of metals. a Dr. Brinnel determined a way to test for hardness what he did was to fire
bullets at different speeds into a test piece and measure the deformations. when a bearing sueface is ruined by
gouging it is called "galling" when it is indented ball bearings it is called "brinneling" it often happens when the bearing adjustment
is too tight but a too loose adjustment will cause it also. adjust your bearings neither too tight or too loose
for longest lasting service.
b4 there was rockwell hardness testing of metals. a Dr. Brinnel determined a way to test for hardness what he did was to fire
bullets at different speeds into a test piece and measure the deformations. when a bearing sueface is ruined by
gouging it is called "galling" when it is indented ball bearings it is called "brinneling" it often happens when the bearing adjustment
is too tight but a too loose adjustment will cause it also. adjust your bearings neither too tight or too loose
for longest lasting service.
