Quote from: Ultramic on May 11, 2026, 05:32:42 PM
Double check the top and bottom bearings are the correct size/angle as per the manufacturers specs. Check the frame bearing surfaces are 100% clean and there is no dirt. Check the bottom bearing is seated against the fork (or crown race if you have it) - the fork may need to be lightly sanded to ensure proper contact.

Dissassembled and re-assembled again, and everything looked fine (bearings in the right angle, crown seated properly, no dirt, etc). I decided to add yet another microspacer on top of the c-ring (so x2 right now) even if there was space between the top cap and the frame, but that seems to have fixed it! Went on a quick ride and there's no play!
Crossing fingers that it stays that way, thanks for the help!

Quote from: Ultramic on May 10, 2026, 09:33:36 PM
That's interesting. Is the c-ring plastic or metal?

It's metal!
My last thought is that when preloading at home, things are not really preloaded, and when riding, the spacers compress more, and that leads to the play?
I've tried again, compressing the top cap by having my gf push on the stem while I screw it in, and after 5 mins riding, there's play again, so I'm really puzzled... It's the 3rd chiner that I built, and I've never had these issues.

I think that I'll take it to my LBS, unless someone sees something I'm missing

Quote from: Ultramic on May 07, 2026, 04:15:23 PM
A few things. Can you confirm your top bearing cover is not bottoming out on the frame, there should be a visable gap when the preload is applied. Second, when you say the expander plug is not moving, did you check this after the headset became loose ? You can shine a light between the gap in the stem to see if the expander plug has lifted from the steerer. Lastly, C ring could be undersized, although I highly doubt this as this handlebar is quite popular and I don't think anyone has reported this issue.

Yes, there's a gap between the top bearing cover to the frame, I even added a microspacer on top of the c-ring just in case.
The expander is not moving, I just adjusted everything again, felt tight, went on a ride, and after I came back, there's play again, lighted up the stem, and it hasn't slipped.

So I really don't know what's going on...

Does anyone have issues with constant headset play? I'm using the KOCEVLO X01 integrated cockpit and can't seem to get it to stay tight.

My process:
Preloaded with the top cap.
Torqued stem bolts to spec
Using an 80mm expander plug (and it's not slipping).
Using a 3mm spacer on top to not bottom out.

Everything feels solid, but after one ride, the play is back. It feels like it's coming from the top bearing/C-ring area.
Any ideas on what else to try?