Thanks for the info guys.
I presume the box ratio is the same as the B4. Started testing today with a 27t pinion and its was a good starting point giving me a ratio of 7.5. I then went up to a 31t which was fine at about 6.5 and down to a 24t which would give me about 8.5. The 10.5 motor was more than fast enough and with that pinion range it gives me plenty to gear up or down depending on the surface.
Really looking forward to racing the X6sq in the summer
