210 disks on left, stock 1200 on right. 9.5" disks of the 210 vs. 8.5 of the 1200. The wheel mount surface of the 210 sticks out about 1/2"(12mm) further than the 1200. The hub and spindle is longer. This should increase the front track width by an inch. Also, the increased caliper pistion diameter will be (hopfully) balanced in the rear with the larger 13/16 wheel cylinders (stock on b310).