I have an issue with the headset on my 2014 SuperSixEvo, and I wondered if any of you had the same issue / had any ideas?
When heavy braking on the front brake, the headset seems to move somewhere (haven't started micro-analyzing it yet). I can feel it kind of click forward, at the end of the braking stage (when I am coming to a stand still, or have hugely reduced my speed over a short distance). Then, when I steer left or right, the headset make a kind of scrawking, plasticky rubbing noise. If I then keep on riding, the noise goes away, until the next time I brake heavily. Under 'normal' braking this does not happen, and the headset has no play in it at all when the bike is at a standstill, or even when I apply the brakes whilst riding along normally, and put my fingers round the headset to check. This only happens under heavy front braking.
Stuff I have checked;
I have taken the whole front of the bike apart, of course, and done the following;
-Checked for cracks at the top and bottom of the headtube, and the angled bearing seats. Could not see any cracks. There was evidence of slight movement of the bearing against the carbon bearing seats in the headtube, by way of a slightly shinier, rubbed area where I assume the bearing race contacts the carbon, but this was not an area which had any gouging, or material removed, just kind of polished a bit through rubbing.
-Checked the bearings for cracks. Nothing. I know it is not possible to check how the bearings respond under load when they are in your hands, but they felt smooth and there was no corrosion or visible damage. Again, like the bearing seats, there was a slight indication of rubbing, but only through slight polishing, and no gouging.
-Checked stem bolt tension, compression wedge tension, etc. All fine. Nothing moves when I spring, and indeed, no sound happens when I sprint; this is only when I heavy brake on the front.
SuperSixEvo, 52cm, with Deda Superleggero stem and bars. 10mm spacer under stem, 5mm spacer above. Cannondale superlight compression wedge. I had this exact set up on a 2012 SuperSixEvo, without issue.
So, given this evidence so far...
Any ideas / thoughts?