When Shimano first released the RS685 and their Di2 R785 companion STI levers for cable actuated shifting and hydraulic disc braking, the calipers included in the complete set were these RS785 models. Borrowing considerably from the excellent XT M785 mountain disc calipers, Shimano built into these road calipers a premium on stopping power and efficiency, while managing weight. Most first generation road and cross disc brake bikes are developed with the mountain bike post mount system, and the RS785's were built to match. Even as the newer bikes and forks turned to the flat mount style, some bikes actually feature one flat mount and post mount, with adapters being made as well. Certainly there are many cyclists out there with post mount road, gravel and cross frames and forks, so the RS785 caliper is still offered.

Slimmed down from its XT breathren, the RS785 features a different hydraulic access point and slimmer overall body. Designed for standard use with a 140mm disc rotor, it can be adapted for 160mm rotor use as well. At 142 grams a caliper, the RS785 keeps weight manageable, and the design is universal, so it is not front or rear specific. If you are building a complete disc brake bike, buy two calipers.

The disc brake pad loading and mounting system is the same as the XT version, with a center pin hole. Shimano built the RS785 caliper to accommodate the IceTech brake pads with or without the aluminum cooling fins. The finned pads are included and we highly recommend them to manage heat most efficiently. The calipers provide consistently reliable, all-condition, fade-free stopping power and excellent feel. The bleeding process is fairly simple, and Shimano has set it up with the RS685 STI levers for a bottom-up procedure that is both efficient and effective. The hydraulic hose and fitments come with the STI lever purchase, but if you need to purchase, the RS785 Hydraulic Disc Brake Caliper is compatible with the SM-BH59-J-SS and SM-BH59-JK-SS kits.

Though reasonably light, the stout aluminum caliper construction utilizes ceramic pistons and steel fixing hardware. The finish is in paint, the color is black. Now you know all you need to. If you require Shimano road hydraulic disc calipers for post mount frames or forks, the RS785 delivers XT/Ultegra level performance. In other words, impressive, consistent action, and utter reliability, without breaking the bank.