I am new to this, so be gentle. I have just bought a s/h frame off e-bay. It is thought to be a specialised. It has a headstock of 34mm (1 and 3/8"😉 inner diamater. What size of fork is required, 1" or 1 1/8"? Any further advice would be appreciated.
It has a headstock of 34mm (1 and 3/8"😉 inner diamater. What size of fork is required, 1" or 1 1/8"? Any further advice would be appreciated.l
You'll want a fork with a 1 1/8" steerer.
Forks with 1" steerers are generally used in frames whose headtubes have an inner diamter of 1 1/8" -- you can "shim" a 1" headset to fit in larger frames (~$28US for a PROBLEM SOLVER headtube reducer [aka "shim"]).
Road bike? Get Campy shifters ...
MTB? Manitou forks are not recommended ... rebuilding (when needed) is unsatisfactory compared with rebuilding other brands. FOX forks/shocks if you can afford it.