Originally Posted by
vintagerando
Is "steerer tube" the head tube?
Yeah. Sorry. I meant head tube.
Originally Posted by
Slash5
Your fork has a 1" steerer tube.
When you say you have a shim it sounds like your frame is designed for a 1 1/8 steerer and has a 1 1/8 headset installed with reducers for the 1" steerer.
This is also what I think.
It might be a confusing situation at first. But after taking measurements, looking at that Sheldon Brown page I sent, and searching for parts, things should line up.