Hi, I'm just starting to into maintaining and upgrading bikes and I've started off on my gf's bike. It's an old rockhopper and I'm upgrading it for fun with cheap'o stuff. I want to change the stem and bars first and the current stem it a one piece thing where the stem is welded to the headset and goes into the steering column. So I want to get a headset but don't know what size or type to get. Does anyone know how to measure what size headset will fit?
