Well my bike just failed its yearly inspection ( MOT) on worn and notchy head race bearings). I have had 3 sets now in the 70,800 miles i've completed on my '99 600FX. This seems a bit excessive as the last ones only lasted 1 to 2 years. I don't stunt, just ride over speed bumps a little too fast.

How long have you run on the same races? looks like i've got a bill pending for £180. Ironically my usual mechanic, who is always trying to save me a few pounds (stirling) thinks the tested was being a bit fussy albeit there is some notchiness to be felt if you really concentrate.

 

mine's lasted 40K and still fine...the stockers. i have a set of aftermarkets ready to go.
after you install them, do you retighten it after everything sets in? otherwise, would lead to premature wear.

 

WOW i wish i had got that sort of mileage out of my first set, i have used pattern parts since but am now biting the bullet and going back to Honda parts. The last set were retightened some time afterwards and my mech. said that they were extremely Loose.

 

from what i've been reading, the aftermarket ones are supposed to be better and wear better...except for yours of course ;-)