i killed judas.

I just built up a new bike and for some reason or another, the headset seems like it wont seat properly. There is a small (<1mm) gap between the top headset cover and the headtube. The headset spins freely when I rotate it. When I rock the bike back and forth, you can feel the slight play. This is a carbon steerer, so I have an FSA compression plug in it, and tightening that doesnt fix anything. The race is seated flushly.

Anyone have any ideas? Its a threadless integrated headset, Campagnolo style, in case you're not familiar with the FSA Orbit CE.

joejack951

First, are you familiar with tightening threadless headsets? Are you setting the preload on the bearings prior to tightening the stem clamp bolts? If not, go read up at www.parktool.com before you break something.

Next, assuming you are familiar with threadless headsets, it has been my experience and that of a few others here as well that integrated headsets, especially Campy style, require a significant amount of preload to remove all of the play and to keep it that way. If you don't remove all of the play at the beginning, it will slowly get worse as you ride the bike. Also in my experience, you need to be careful with overtightening the plug in the steerer tube as that can cause the tube to bulge and affect your ability to properly preload the bearings and/or clamp the stem in place. Remember that the plug does not hold the preload on the bearings. It only allows you to preload the bearings. Once the stem bolts are tightened, the preload is maintained by those bolts only. The plug only offers internal support for the steerer tube at that point.

HillRider

Along with being sure the stem bolts are loose when you adjust the headset, be sure there is a 2-3 mm gap between the top of the steerer and the top of either the stem or an above-the-stem spacer, whatever is on top and immediately below the compression plug's top cap. If there is no gap, you are just butting up against the steerer and not adjusting the headset.

i killed judas.

I was under the impression that tightening the compression plug pre-loads the bearings? Am I wrong? FWIW, I have done this before on 2 other bikes and didnt have a problem.

HillRider

That is correct, tightening the compression plug's top cap against the stem or top spacer does preload the headset. However, that assumes there is a gap between the top cap and the steerer to allow the steerer to be drawn upward and that the stem bolts are loose to allow the steerer to move.

i killed judas.

There is a gap, but I'm actually being led to believe that the gap may be TOO large. It seems the hex bolt is just barely reaching the plug inside of the steerer. The plug is still getting tight, but there still is play in the headset. Could this mean the problem may be somewhere else?

joejack951

There are several types of compression plugs. Some use the top cap bolt both for expansion and bearing preload. Some are secured in the steerer tube first by tightening a bolt that expands the plug and then a bolt through the top cap or the top cap itself is turned to preload the bearings. There are probably other variations as well. Regardless, you need to be sure that the plug is anchored in the steerer tube otherwise you won't be able to add any preload to the bearings.

Pictures of your plug or links to something similar would help.

i killed judas.

JTGraphics

In your case I'd remove bearings and double check everything first, I know you fill that you have it correct but double check anyways.
Make sure bearings are not flipped, make sure you have the required space from steerer shorter that stem.
The compression plug you have should draw the stem down setting pre-load then tighten stem bolts.
You sound like your doing it correctly so don't go over tightening things, double check first.
Pictures would help of the assembly if you need more help.

joejack951

The style of compression plug shown isn't as intuitive as some other designs, though it seems to work well. I have the same set up for my Winwood fork.

First, before inserting the plug, you need to unthread it from the top cap a prescribed amount (detailed in the instructions and I can't remember the number off hand). Basically, you want enough threads engaged but not too many that you don't have enough to set the preload. After insertion, you tighten the center bolt (5mm on my plug) which anchors the plug in the steerer tube. This needs to be set tight enough to not slip but not so tight that you significantly bulge the steerer tube. Now, you can finally set the preload which is accomplished by using a 6mm hex key to turn the top cap. This draws the plug up into the cap. You'll find that you can tighten and tighten and likely never cause the bearings to bind. Try to feel for the point where the plug slips in the steerer tube and stop there. If the adjustment doesn't hold over time, tighten the plug more and use more preload on the bearings.

i killed judas.

This is where I think that I am going wrong. I dont think that the center bolt is long enough to reach the compressor at the depth it needs to be in order to even pre-load the bearings. For instance, the plug should be below where the top of the stem would sit, but I have 6mm of spacers above the stem. SO I would need a center bolt that is about 10mm long to get the reach to the plug that sits 3-4mm below the top part of the stem.

I apologize if I did a terrible job at explaining that.

joejack951

I don't think you understand how that compression plug works. I failed to explain it above so I'm going to recommend that you take it out of the fork and study it to see what's going on. It is different than a standard top cap and star nut system. The top cap on your compression plug acts sort of like a standard top cap and bolt together and the expanding wedge is like the star nut. The center bolt in the expanding wedge is only used to anchor the wedge though. The top cap has a separate hex feature (larger than the wedge's hex bolt) that you can use to turn the top cap and draw the anchored wedge towards the cap (just like turning the bolt on a standard system would draw the star nut towards the top cap).

For this system to work, you need to have the expanding wedge unthreaded some amount from the top cap before insertion and anchoring the wedge though. As shown in the picture, the wedge is fully threaded into the top cap. If yours looks like that when you are installing it, that's your problem. You need to unthread it by a few millimeters at least to leave yourself room for adjustment.

So, starting with the wedge only partially threaded into the top cap and the wedge expanded to a slightly smaller diameter than the ID of the steerer tube, insert the compression plug. Using a 5mm hex key, tighten the wedge in the steerer tube. Now, using a 6mm hex key, turn the top cap to add preload. [Note that your hex key sizes may be different but the one to tighten the wedge will be smaller than the one to turn the top cap.]

Am I making any sense?

i killed judas.

I understand how it works entirely, I was just using a different method. I was putting the compressor in sans center bolt and top cap, tightening the compressor to the inside of the fork steerer, then inserting the top cap and center bolt and tightening that to load the bearings. Same end result, just two different ways of going about it. Unfortunately, neither are working because the problem persists.

If the lower race was chewed up a small amount, could this be causing the problem? Maybe it is causing an ever-so-slight deviation as to not sit the lower bearings correctly which is leading to the play in the headset? I dont know, Im really stretching for ideas at this point.

joejack951

What do you mean by chewed up a small amount? Is the race damaged where the bearings seat? If so, yes, of course that could be the problem.

The other problem could just be that you are not adding enough preload to the bearings. I'm telling you, they need A LOT.