I have a 2011 S-works Roubaix and it has a cane creek 20mm cone spacer below the stem. I need to swap it out for the shorter spacer like what comes on a Tarmac, but so far both of the spacers I've tried have bound up once I tightened the top cap screw. The fork turns, but it's not very smooth. Loosening the top screw any makes it move freely of course, but then I get rattles when I bounce the front end, telling me it's too loose.

Using cane creeks "headset finder", it told me I needed an IS42 headset for a 2011 S-works Roubaix, so I bought a complete short-cap IS42 setup and simply used the short dust cover on my current headset. Visually the underside of both caps looks the same to me, but obviously something is different. I also tried a 6mm thick FSA dust cap/cone spacer and it bound up as well, as if the cap is rubbing on the head tube before it makes contact with the bearing.

The mechanic at the shop in passing (I was in there getting a replacement crank part under warranty) handed me a 1-2 mm thick spacer to put under the short conical cap, but said that there may end up being a small gap now between the top of the head tube and the bottom of the conical spacer. Not optimal, as dust will now get in there.


Ideas? Ideally I just want what comes on a Tarmac, but specialized doesn't appear to sell just that part.