I've tried 13/44, 40 and 35t on my SM'd EC300, and so far the 35t makes the most sense on the road. I used an on-line gearing calculator which gave a top speed on this gearing of 112mph (which given the aerodynamics it'll never achieve), in the real world I've had 100mph out of it. I may try a 14t front with the 40 rear next.
The standard 2 pot EC caliper is just about acceptable with a 320mm disc, but I have a 4 pot Brembo to go on when I get round to making a mounting bracket for it.
