Hi so around two months ago I built up a Kilo TT from the frame up. This was my first time installing a threadless headset on a bike and I was using the Cane Creek AHeadSet. It seems though that the plastic compression ring that comes with this specific headset is not really doing its job completely because even though I have the start nut and stem tightened down quite a bit, when I hit a bump in the road sometimes I can hear a *thunk* sound coming from the top of my steerer tube as if metal is hitting alloy.
So my first assumption is that the plastic compression ring is not doing its job and keeping the steerer tube centered in the head tube.
Also it may be relevant that I am using a 1 1/8" stem shimmed to fit the 1" steerer tube which could also account for some looseness.
Any insight would be appreciated, thanks.