no, easton do not recommend using bar ends on the EC90 range - the ends are not reinforced in an effort to keep weight down i presume.
the EC70 range
are deemed compatible though.
i've used easton in 25.4mm clamp, but now have oversize 31.8mm, and have used Titec riser and now Giant flat bar. both these are great if you can find them, and accept bar ends. it's not to say you can't crack the ends from over tightening - i heard a crack with the Titecs - so you still have to be very careful. i suggest scouring/roughening the ends of the bars where the bar ends clamp over to improve their 'grip' on the bar, meaning you don't have to tighten them as much to achieve the same 'tightness'. i used some sandpaper.
