Good day, I'm new to the whole bike building process, but I've finally decided to make the step and build a semi-nice bike.
I've bought a really nice aluminium frame 2nd hand, but its sizing has me stumped. The inside diameter of the front part of the frame (where the front fork goes in) is ~32mm. I've been searching online (e.g. http://www.sheldonbrown.com/cribsheet-headsets.html) for a couple of days, but I cannot understand what type of fork I should get.
Should I get an 1 1/8", 1.5" or some other type of fork?
EDIT: After some investigation, the bike frame is an Alpinestar Almega DX, the same as in this picture I couldn't find any specs though :(
Here is what I measured, when I said it was ~32mms (apparently it's the headset, not the pipe itself). The other end is the same size.
Thanks!