Shimano 600 headset bearings
06-26-22, 09:09 AM
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Shimano 600 headset bearings
Hey!
I took apart Shimano 600 headset and assumed it has caged bearings. But it had loose bearings and I dropped a few and now I'm not sure how many there were. I understand you can fit as many as you can or leave one out if its a precise fit. One thing is weird, it has 3,9mm loose bearings. I thought shimano 600 had 3/16" or 4,8mm bearings? I ordered new 4,8mm and just now realised the old ones are not even close to 4,8mm! Wrong bearings or different setup?
Thanks for your help!
I took apart Shimano 600 headset and assumed it has caged bearings. But it had loose bearings and I dropped a few and now I'm not sure how many there were. I understand you can fit as many as you can or leave one out if its a precise fit. One thing is weird, it has 3,9mm loose bearings. I thought shimano 600 had 3/16" or 4,8mm bearings? I ordered new 4,8mm and just now realised the old ones are not even close to 4,8mm! Wrong bearings or different setup?
Thanks for your help!
I'll post pictures. They go to my album if someone wants to take a look!
06-26-22, 11:08 AM
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06-26-22, 11:12 AM
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I have never seen a Shimano 600 headset w/o a caged bearing as assembly would be too time consuming. The HP-6400 which is the 600 Ultegra did have caged bearings and if memory serves they are 5/32"
06-26-22, 11:23 AM
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Yes. 5/32" bearings are the correct size. I just remembered wrong and assumed they were 3/16 
never trust your memory. Maybe it has been serviced at some point and the mechanic didn't have caged bearings..
Edit: should I change into a cage or does it matter?
never trust your memory. Maybe it has been serviced at some point and the mechanic didn't have caged bearings..Edit: should I change into a cage or does it matter?
Last edited by wontons; 06-26-22 at 01:00 PM.
06-26-22, 04:43 PM
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I prefer loose bearings, one less than will fit in the cup, the additional bearing(s) can only help take the load. You can find engineers (and I are one) that will say caged are better but I believe this is only the case for polymer cages you are unlikely to find for a bike headset that might minimize metal to metal contact, retain grease better, better high speed performance (not cycling speeds), etc.
06-28-22, 08:51 AM
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There have been several iterations of the "600" hedset, some using 20 3/16" balls in each race and others using 25 5/32" balls in each race. Still others use cartridge bearings. If your version had 5/32" balls originally, that what you should use when you replace the balls.
