Hi, I know there is a similar thread here but slightly different problem.

I got a Cannondale Trail SL2 a few months ago and it seems like the headset always develops play in it after a ride or two. It has a RockShox Recon Silver TK fork and Tange Custom 1.5" headset.

I took the top cap off, loosened the stem and took it off too to make sure it can be pushed down to preload the bearings. There is a 3 to 5 mm gap between the top of the steerer and the top of the stem, and the top cap can be screwed down enough that the headset binds up, so I'm pretty sure the top cap is not bottoming out on the steerer. I tightened the stem bolts on pretty tight to the steerer by hand but not sure of the actual torque. It must be pretty high since it almost looks like the ends of the stem are coming in towards each other instead of perfectly parallel (too tight?).

When I get it to turn freely, it seems like there might almost be an imperceptible amount of play when I rock the bike with the front brake and feel right around the edge of the head tube and the dust cap. Then if I ride it more, it seems to always develop visible play with the rock-it-with-brakes-applied test.

TL;DR: Why does the headset seem tight upon assembly/adjustment but seemingly always develops play? Is my stem slipping up the steerer? I've just tried some carbon assembly paste to see if that makes any difference. Is something in the wrong order/missing? Fork crown race not seated properly? Do I have an ovalized head tube (wouldn't it always have play from the start with an ovalized HT)? I guess I should just take it back to the shop, but that is a pain... ughhh... Thanks for your help!

milkbaby: Maybe "pretty tight" is not tight enough. If you are using a multi-tool or the short end of an "L" wrench you might not be getting it properly torqued. Are the clamp bolt threads greased and the clamp and steerer surfaces clean? Is the gap in the stem open, so that the bolts are clamping the stem to the steerer and not just squeezing the "ears" together?

I did grease the stem bolts. Out of fear of overtightening, I grip the hex wrench (L-shaped) pretty close to the bend so as not to use too much leverage. It does seem that I'm tightening down hard, but if I recall, it does seem like the "ears" of the stem are being squeezed together, not sure if it is gripping harder right on the steerer. I do remember maybe some grit/sand that was in there when I took the stem off last night. I will carefully clean everything and reassemble again.

Any tips on making sure the stem is actually clamping down on the steerer rather than the ends/ears of the stem just squeezing together? Thanks!

Headtubes ovalize over time , typically creating front to back play but not side to side play. Do you have lateral play in the headset ?

""I got a Cannondale Trail SL2 a few months ago""

did you buy it new or used? if you bought it new you should be taking it back to the shop. if it keeps loosening up there may be a an issue with it, there may even be an know issue (like in the auto industry where they put out Tech Service Bullitens) that needs to be addressed. if the bike is new you should not be turning wrenches on it

I'll have to check when I get home to see if there is lateral play, but I bought the bike new maybe 3 or 4 months ago and haven't ridden a ton, so I'd guess that it's too early to ovalize the HT from wear? Obviously, still a problem if it's not working right!

Taking any bike to the shop is a pain, so if it's relatively easy, I'd prefer to just do the work myself if I have the tools and enough know-how or it seems easy enough to learn. I will stop by the LBS tomorrow and ask them about it while I'm looking for some bike stuff. I have the Leonard Zinn book which explains most of the whys and hows decently, but obviously not as good at answering my tricky questions as you forumites! Thanks!

If you can tighten it, and it loosens over time there are two likely possibilities.

1- the crown race or a head tube cup isn't seated fully and is settling. This is common on newly fitted headsets, but eventually cures itself since at some point the crown or cups will bottom out.

2- the stem is slipping up the steerer. I've heard of this but never seen it happen. The vast majority of riding forces are on the lower stack so only the reaction force acts to move the stem up. But it's possible, and the traction compound you're using should solve it.

If you can never get it truly tight, look for s sloppy fit. Usually it'll be at the lower head tube cup where the tube has become bellmouthed over time. It could also be the crown race, or one of the other cups. To check, drop the fork and check everything. I've also seen the steel races get loose within the cups on certain headsets, and on integrated headsets the bearings not seating properly.

Try cleaning the steerer tube with alcohol before installing the stem.