I went to adjust the stem on my 06 Roubaix Pro and instead of a star nut in the fork, there is a bolt that looks as though it drives a circular shaped wedge down into the fork. This bolt backed out when I removed the stem cap. I don't know what the torque spec is for it, and it doesn't appear to preload the headset. There is NO info on The Specialized website. I looked high and low. Any suggestions would be helpful.

Try going here. They've got good instructions on how to...

www.parktools.com

I assume your steerer is carbon. That inner bolt tightens and compresses the compression plug. The stem cap which screws on top actually pulls on the steerer tube and provides preload.

If you have a carbon steerer, DO NOT put a star nut in it. It ruins the fork. You'll have to discard it & buy a new fork.

After relentless sleuthing online, and careful observation of the mystery part, I figured out what this thing is all about. As it turns out, the ham-fisted, knuckle-dragging mouth-breathing goon who assembled this bike at my LBS didn't install it deep enough in the steerer. When I picked up the bike this week I noticed the stem cap was not seated against the stem. I wanted to rectify this as I knew instinctively that the headset bearings could not possibly have the proper preload, and sure enough, when I squeezed the front brake and rocked the bike forward and backward there was slop in the headset. The stem cap was fully tight, but it was tight against the top of the compressor bolt, with a gap between it and the stem of about a sixteenth on an inch. I simply loosened and then gently tapped the compressor lower into the steerer tube, tightened it and proceeded with the proper preloading of the headset bearings. The truly irritating thing about this is that I know good and well when the "mechanic" assembled this fork he had to know it was incorrect. Or he may simply be a complete idiot. Whatever the case, it's fixed. Thanks for the replies as they pointed me in the right direction!