I have a 2 month old Surly Cross Check with threadless headset. A couple of nights ago I took the stem off so I could move some spacers around to drop the bars. Ever since then, I have been feeling a little wobble/play in the headset when riding. I read this:

https://sheldonbrown.com/headsets.html


So I tested by holding down the front brake and pushed back and forth and I feel some play in there. I took everything off again and put it back and made sure I tightened down the cap bolt and the bolts on the stem as tight as I could but I still feel the wobble. What am I doing wrong?

Did you remove too many headset washers? perhaps you don't have enough stack height to prevent the top cap from bottoming out against the steerer tube. You need to be about 2 - 3mm above the steerer before tightening the top cap.

If you have clearance, turn the front fork sideways and rock the main frame of the bike forward and back and check for play. If loose, check the front hub. Is the QR tightened? Check the brakes themselves; do they have play? And check front hub bearings to see if the hub has play.

Are you sure you replaced all spacers, either above or below the stem. You need to tighten the cap bolt until the slack is gone. If you can't, you left something out. The cap bolt is used to tighten the headset. The bolts connecting the stem to the steerer should be loose for this. Once the headset it tight, then tighten the stem/steerer bolts.

Make sure that you have some stem or spacer above the top of the fork steerer tube for the compression cap and bolt to push down on. If the cap is simply pressing on the top of the fork, it cannot preload the bearings. Also, make sure that the pinch bolts on the stem clamp are loose before you tighten the compression bolt. Only snug up the stem pinch bolts after you get the play out of the headset.

Don't trust your memory. Maybe you dropped a spacer or something.

It's really easy to verify whether you have enough spacers. Leave stem clamped, and remove top cap bolt, and top cap. Is the top of the steerer recessed below the top of the stem/spacer stack. Note also that some top caps have a step on the underside, so the steerer has to be reessed by more than the depth of the step, otherwise the top cap bottoms against the steerer and cannot push the outer stack down to compress the headset.

The the possibility is that you pulled the expander plug or star nut up and the top cap bolt is running out of thread without tightening the headset.

Beware, that's too tight! (See here) I'll also put in a vote for 'lost one spacer'. You need the stem cap to be tightening down on spacer, not on steerer. With loose stem bolts, tighten down the cap just until the play goes away (not sure how to tell if there's play if the stem is not tight yet), then you can crank down on the stem bolts, and once the stem is securely holding down the spacers, you don't even need the cap in there (except keep it on, in an accident an open steerer tube could core you like an apple)

Another possibility related fact: a newly-pressed headset can be nice and tight at first, even if it is not pressed in fully, but as the bike is ridden, the weight will eventually press the headset (and fork race crown) home and leave some slop, so a headset adjustment would be in order. But yours doesn't seem to have happened due to time, but to taking it apart and putting it back together. But, you may consider making yourself a ghetto headset press (bigass bolt, nut and stack of washers), taking the steerer out altogether, and giving the headset cups a squeeze in the headtube to make sure they're fully seated.

Sometimes purists will insist on refacing new headtubes, which I guess means turning a perfectly round, perfect diameter circle in the inside top and bottom of the headtube so the headset will press in perfectly, I wonder if it's possible that your headtube was not perfect and should have been faced? My new CC frame didn't seem to have this issue, I don't know how common it really is.

Just another thought, not really any different from above, but if you tightened the cap bolt without first loosening the stem bolts, then you did nothing but tighten bolts. You need to loosen stem bolts so that tighetning the cap bolt can slide the stem downwards and take up teh slack, then tighten the stem bolts back up.

Another test; are the spacers below the stem at all loose? Can you slide them up and down at all (definitely bad), or even spin them around? That's slack that needs to be taken out by moving the stem downwards.

One more: back in this other thread, you reported "No spacers on top and 4 1/2 inch on the bottom" -- but that was the one you returned right? Maybe that's a standard configuration as delivered on REI stock full bikes? 4.5in = 114.3mm, so it's probably actually 110 or 115mm of spacers. For that bike anyways.

Thanks for all the suggestions.

Rube, that was for the 54 CC I returned but this one came with the same configuration. I will loosen it all and tighten it back by your instruction. I did read that if I tighten too much that could crush the bearing, hopefully that's not the case.

I didn't lose spacers, see picture as proof

I took everything apart and put it back together 5 times tonight and every time I do it , I still have the wobble. I tried changing the spacers around to different configurations and currently have it back the way I got it with the three spacers under the stem. Still wobbly.

Does anyone have any other suggestions? Is it just a minor annoyance that I can live with or should I be concerned about the integrity of the bike when I'm riding?

Did you confirm that the stack height is tall enough? Is it possible that the centering cone is missing or damaged.

If something is wrong, you can repeat the assembly 1,000 times, but it'll still be the same.

It's also possible that something else entirely is going on, for example the cup itself being sloppy in the head tube.

Check stack height, check that the cone is OK, and if it still doesn't tighten visit a local shop or co-op and have someone knowledgeable take a look. Probably something simple and obvious to someone who can put his eyes on it.

I see the Cantilever-cross brake headset hanger.. so this may not apply here and now,

To general readers .May I suggest a QBP locking spacer .. its like a seat binder band for the fork ,
so pinch bolt keeps it there .

Having an Integrated headset , doing the same spacer shuffling ,
the fork would fall out, headset and all .

Now , with the first spacer above the headset, being that , the fork stays in the bike ..

of course to re adjust the preload on the headset, all the pinch bolts around the steerer need be loose ..

heres what they look like : https://problemsolversbike.com/products/locking_headset_spacers

Is the brake cable hanger clamped down when you are adjusting? Looks like it clamps to the steerer and may interfere with adjustment if it is tight.

I had my first experience with that yesterday. I'm using a Problem Solvers cross hanger. I love it. I assembling a bike with a new fork, stem and bars from what I have used. This clamp keeping the headset adjusted is gonna make getting the bars where I like them a piece of cake while swapping spacers around.

I don't know if one needs to or not, I put a 2.5mm spacer between the headset and the clamp.

Thanks for all the suggestions. I had the brake hanger and stem bolts loose when I tightened down the cap bolt and then I tightened the rest. There is still a little wobble. It's only real noticeable if I do something like ride off a curb or if I do the test holding the front brake and moving the bike back and forth.

I have to go down to my LBS some time soon to bring in a new frame set that I am building so I will have them look it at then

this was my thought when i saw the picture

to the op
make sure that
1
the stem protrudes above the top of the steerer tube
2
there is clearance between the bottom of the top cap and the top of the star nut in the steerer
3
both stem bolts and the brake hanger bolt are loosened off before adjusting the headset

other possibilities
perhaps a part of the headset such as the bevelled ring was inadvertantly removed and not replaced
perhaps the bearings were removed and installed upside down
perhaps there is a seal or dust cap interfering with correct assembly of the top or bottom cups

curiouser and curiouser. Wilfred has some good addl suggestions to look into.

in the meantime, I don't think you should be too worried about your safety. If the stem is firmly on the steerer, then it is not possible for the fork to fall out of the headtube (except in such extreme trauma that the headtube rips completely open, in which case you've got bigger problems)

Only certain things can go wrong with a threadless headset. If it isn't stack height, and it isn't the brake cable hanger not being flat over the top cup, then it's something like a missing or damaged conical bushing that fits in the gap between steerer and top cup. Or the bearing races are put in the wrong way so the cones are riding on the retainers and not the balls. But those are the 99% issues and worth really examining first. In terms of proof of stack height via picture, that can only be done with the top cap off showing us the clearance of 3mm or so from the top. Hopefully you don't have a cracked head tube and that's causing the problem. Cross the fingers that you don't have the 1% of issues.

rms, it sounds like the brake/wobble test is new to you. Did you try it before this exercise, or only after? Since you say even now the problem is not felt all the time, perhaps it was present before and you never noticed, but now after reading you are more alert for it? Inverted bearing/retainer might have been there before for instance.

Lets see a photo of the inside of the top spacer; just remove the top cape and with all the spacers still in place, take a picture inside. This will definably show if there is enough spacer height too allow the headset to be tightened..

I remember.....I used a thin spacer under the cross hanger because the drop arm hit the upper bearing cover without it and the clamp would not lay flat on the cover. If the OP's bike had a spacer there and he rearranged them, this might be his problem.