Thanks for the help Kev,
I've been running a 46 for the last 20,000Km witch was put on at the same time as the PCIII. As most of my commuting is at 80 - 100km/h (plus that little extra that's needed to keep up with the traffic) I would like to drop the revs a touch, I find that the surging is minimal (for a single) and dont think dropping back a tooth will make much difference to the surging.

You have obviously tried a variety of combinations and if you have a better idea, I'm listening.

Regards

Paul