Caliper Brake Reach
The Pacer and Steamroller* frames use standard reach (47-57mm) calipers, although some short reach (40-50mm) calipers will work. We do not recommend the use of anything other than a good quality standard reach brake, including Sidepulls with 53-71mm or 61-78 reach.
Short-reach brakes are the modern standard: 39-50mm brake pad positioning from center of the frame mounting bolt to center of the pad bolt Standard-reach brakes are often called "long reach" 47-57mm brake pad positioning from center of the frame mounting bolt to center of the pad bolt. Back in the day, just about everything was this size. We still use it on our road frames because we like to have extra clearance for big cushy tires
*Steamroller framesets made until 2007 were not designed with a brake-specific upper stay bridge. Adding a rear brake to these frames requires the use of a front standard reach caliper on the rear of the bike (a front brake should also be used on the front of the bike). You'll need some extra mounting hardware to secure the caliper to the seat stay bridge (see photo A). Front brakes mount normally. Steamroller frames made since 2007 (beginning with serial number series M701XXXX) do have a brake-specific bridge (see photo B), and normal standard reach front and rear brakes may be used on these frames. Note that there are still no rear housing stops of any kind. Should you decide to add clamp-on housing stops, the O.D. of the Steamroller top tube is 28.6mm.
Tire clearance will vary depending on the caliper and tire used.
photo A, Steamroller bridge pre-2007
photo B, Steamroller bridge, post-2007