thanks for your suggestions.
I had seen the un54 68x115. 2 questions arise;
1. Does being 1mm shorter axle make a critical difference?
2. Does it have symmetrical axle like my current 600ex does?
The answer to Q.2 seems to be that no-one really knows. I've search the web high and low, not even our mate Sheldon can shed any light on it (he gives the axle pertrusions for cup n cone bb''s but not for sealed ones)
The 600ex crankset I have, was designed for use with 68x116 symmetrical bb, that much is certain... does anyone know....help...I'm on a wheel of confusion (would a wheel of confusion have a symmetrical axle?)