Originally Posted by
Chombi1
Actually, it looks like an A9/B10 "hybrid" A9's are all aluminium, except only for the bearing cages. It seems like the fork crown race and the top head lug race are B10 Delrin pieces.....
Ypu're right; I hadn't noticed that.
Forgot to mention, the top locknut is most likely from a B10, but those were identical to A9 locknuts, except for the "Hinault" model branding.
Both A9 and B10 headset were available with the Hinault branding. We went through thousands of them at Trek.