You know, I asked the local Paramount Expert, and was told it used 700c with regular long reach Record Calipers. The pads are at their limits on the slots. Took measurements from the Carlton Professional vs the Paramount. There is a half in difference in length, from the brake caliper mounting bolt to center of front and rear dropouts. It's crazy. Seems to me the Carlton Pro is a much better built frame set all around too.