A9's (both ancient needle roller types) have done around 20 years without replacement in 2 steel frames of mine- not daily use but the track iron has seen 10 years of twice weekly use for example. Needle rollers were da bomb- fundamentally better for axial loads which, er, a headset sees mostly.
A9's (both ancient needle roller types) have done around 20 years without replacement in 2 steel frames of mine- not daily use but the track iron has seen 10 years of twice weekly use for example. Needle rollers were da bomb- fundamentally better for axial loads which, er, a headset sees mostly.
Even the cartridges are OK.
S.