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Compression Plug Coming Loose?(5 posts)

Compression Plug Coming Loose?SamDC
Jul 7, 2003 12:23 PM
Recently built up a new frame and the fork that came with it has a carbon steerer. After a few miles the steerer tube will develop some play in the head tube. I'm fairly certain I'm installing it correctly (pull on the steer tube to take out as much play as possible, then tighten the compression plug to take out the rest and finally tighten the stem bolts... right?).

DC streets are notoriously bad, so my theory is that the bumps are jarring the compression plug loose. However, this is my first fork with a carbon steerer so there is a strong possible it may be user error.

Could it be something else? Any advice or suggestions? I've tried cleaning the inside of the steerer tube but that doesn't seem to help much. I'm gonna pick up a new plug this evening and see if that works. If it doesn't, I'm gonna bite the bullet and get a fork with a metal steerer, but before I do that I wanted to get some 'experienced' advice.

Thanks for looking!
re: Compression Plug Coming Loose?JohnIV
Jul 7, 2003 12:49 PM
I had the same problem not too long ago. My solution was taking some fine grit sandpaper, and LIGHTLY roughing up the outer diameter of the steerer. I also did the same in the inner diameter, to make sure the compression plug was wedging itself down in there, and not just turning. Make sure to clean off the carbon dust afterwards. That stuff could make it slip as well. FYI, I did this on a Reynolds Ouzo Pro. Hope this helps.
Thanks! Will try that tonight. (nm)SamDC
Jul 7, 2003 12:54 PM
re: Compression Plug Coming Loose?gav
Jul 7, 2003 10:12 PM
If that doesn't work try a FSA compressor cap maybe?? I'm not sure what cap you currently have, but I had the same problem with my LOOK cap which was just crap.. The problem with it was that it wouldn't pull the fork steerer up when you turned it, it just expanded itself so there was never any pull upwards. That would mean that the headset would loosen up everytime I hit a bump. With a FSA compressor cap, there's two adjustments, one to expand the cap, and the other to pull the fork steerer up, just like if you're cranking down the star nut for a alloy steerer.. It went on tight and stayed that way for me.. Hope that helps..
JohnIV is rightMr Good
Jul 8, 2003 7:50 PM
The compression plug is only for headset adjustment, it doesn't hold the whole assembly together. The stem clamps on the steer tube and holds everything in place, and prevents the headset from coming loose. If the stem is slipping up the steer tube, then it's forcing the compression cap up as well.

I'm guessing the carbon steer tube is very shiny--glossy and slick, right? Your stem will not stay clamped on that thing unless you use some VERY fine sandpaper and rough the surface a bit. People will tell you that you can't sand carbon fiber, but you're not. You're sanding the heavy clear coat on top of the carbon. Just enough to remove the gloss, and just where the stem contacts it.

You can also LIGHTLY sand the inside of the stem clamp, and the slick aluminum plug that goes insite the steer tube. After doing this the whole thing will stay adjusted without excessive torque on the bolts.