dombey19

While I have a lot of experience with the older quill style stems, I am a newcomer to the newer fork/stem arrangement in which the stem simply tightens on the fork steer tube. I seem to have a certain amount of "buzz" in my fork when I hit bumps, although there is no noticeable wiggle if I lock the brakes and attempt to roll the wheel. This is the kind of "buzz" or rattle that would signal a loose headset if I were using a traditional headset. I have looked at various instructions on how to tighten the headset by loosening the stem bolts and then "preloading" the bearings with the preload or cap bolt. Tightening this bolt doesn't seem to make much change however. Most instructions say to be certain the wheel turns freely, but I cannot seem to make it do otherwise. That is, under the traditional system one might turn the upper cone down until the wheel begins to bind, then back it off until the adjustment seems right. Is that possible with the threadless headset? Some discussions suggest that if you turn the cap bolt far enough the play in the wheel will tighten up, but that doesn't seem to be the case for me. I feel that I could adjust the headset successfully, if I knew what "too tight" is. But I seem to be turning the cap bolt (which definitely is threading into a plug in the steerer tube) with no effect.

ridethecliche

Do you tighten the compression plug enough before tightening the stem?

AEO

which type of headset is it? might be improperly assembled with top bearings in bottom and bottom in top.

dombey19

This is a new Litespeed Siena, with a Cane Creek headset, assembled at the factory. I can't tell if the compression plug is "tight enough." No amount of tightening I do seems to make an appreciable difference in the wheel play. I can feel the cap bolt getting tighter and I have resisted really twisting it tight. But I certainly can feel it threading in and starting to become snug.

merlinextraligh

1) does the stem, or the spacer, stick up above the steerer tube? It should be a couple of mm above the top of the steerer tube.

2) If the compression plug isn't far enough down in the steerer tube, you can bottom out the screw on the top cap, before you're putting any load on the bearings, in which case you need to move the compression plug further down, or get a new one.

And yes you should be able to tighten the top cap enough that you feel resistance in turning the forks, and then back off.

However, if you've got it to the point that there is no movement when you put the front brake on and raise the back wheel rolling forward, then you've got enough "preload"

The desired "tightness" on the headset is the same as with a quill stem/headset setup, just a different way of adjusting it.

DaveSSS 

The new integrated headsets with angular contact bearings do NOT tighten the same way as old quill stem headsets, or conventional threadless headsets that use the same bearing and race design. The old design was very sensitive to applying too much preload.

The new angular contact types take a lot more force to adequately preload the bearings. You might apply as much as 5Nm of torque to the top cap bolt and not feel any increase is rotational resistance. Sometimes you have to get on the bike and ride it to notice that the front wheel does not readily return to a straight ahead position after a turn. That's a sure sign that the preload is too high.

Be sure that the stem clamp bolts are loose when you are tightening the top cap.

merlinextraligh

In either instance, if it's not tight enough, there will be play that is noticeable when you hold the front brake, and if its too tight, the handlebars won't turn and recenter freely, correct?

So the tests for how tight, are the same in each case, aren't they?

DaveSSS 

Absolutely not. The old check for play, where you clamp the front brake and rock the bike is worthless with the new integrated headsets. Tighten the top cap bolt significantly and only loosen it if the fork doesn't readily self-center.

merlinextraligh

ok, so what is the problem if it is tight enough that there is no play in the fork, the bike steers smoothly,and self centers without friction?