I spent a little time looking; the Specialized headset is classified by SHIS numbers; one for the top and one for the bottom, which is not combined except through Specialized and Cervelo, but apparently can be purchased separately. The problem is, while the top is simply a standard Campy 1-1/8" Integrated (ISi) Italian Threadless SHIS:IS42 - The bottom is proprietary SHIS:IS49/37 - 1-3/8" Integrated (IS). This smae headset, bnottom and top is also used by Cervelo, but I could only Italian web stores that sell them.
Thank a lot guys, i ended up going to my dealers and odering a replacement headset. and onespeed, that was the trouble italian top and two sizes, so i played it safe. thats a question to hill i only had this bike out in the summer months to, so like you say how did the bearings go wrong. both top and bottom were knackered. maybe i tightend the top a little to much i dont know,