Oh this is interesting:
http://yacf.co.uk/forum/index.php?action=printpage;topic=28822.0
“Thanks for the help Iddu and others :thumbsup:
I’ve finally solved the problem(hopefully ::-)) after JE James cycles phoned me back today and told me that Trek have their own specific sizing for the external diameter of the bearings in their integrated headsets,hence you can only buy spares from Trek ::-)
I’ve ordered 2 while I can in case they stop making the one I need at any time 8)
Many thanks to JE James cycles.Good service.”