thanks for the diameter, we've stuck with 11/16" on the left plate and 1" on the right. Got the rear back laced up and the 16" rear wheel looks tiny! still waiting for my wheel builder for the front which will also be a 16" and the hub... a pair of half width bsa 8"ers pressed apart and pressed together with the non brake half put on the parts shelf. No BSA parts were harmed in this exercise, they could be reinstated if I wanted poorer brakes! Hope to have it on two wheels by close of next week, just need to sort out the trail, may end up making new sliders with a leading axle and a brace between them.