I had this issue too, for almost three years, on two bikes. And the issue is a crappy expander plug. You can fix it by improving the grip by increased surface contact area or by better plug surface. Or get both: https://www.tradeinn.com/bikeinn/en/pro-carbon-plug-ud-long-bike-headset-expander - this solved the issue once and forever.

Really, send it to the bin and and get a good one.

Quote from: Da11as on June 26, 2026, 04:04:42 PM
I had this issue too, for almost three years, on two bikes. And the issue is crappy expander plug. You can fix it by increase grip by increased surface contact area or better surface. Or get both: https://www.tradeinn.com/bikeinn/en/pro-carbon-plug-ud-long-bike-headset-expander - this solved the issue once and forever.

Really, send it to the bin and and get a good one.

Thanks, I will get new plugs. Are you applying grease on that middle bolt before tightening?

Quote from: dedroo on June 27, 2026, 03:54:42 PM
Thanks, I will get new plugs. Are you applying grease on that middle bolt before tightening?

In my bad cases it didn't affect the grip. With the new plug I installed, it holds well even without paste.