The J03A Resin Disc Brake Pad with Spring with Fin replaces the previous generation J02A, and is now rated to be 40% more durable, with no loss in performance or changes in features otherwise. This pad system was developed to high standards for Shimano's M9000 series XTR and was also used in several road and cross brake designs as well- see compatibility below.

Shimano's 2-piston XTR XC/Trail-level disc brakes were developed for optimal cooling and heat dissipation. Heat build-up at the caliper can lead to a hydraulic temperature increase that saps power, induces fade, and can leave you several yards off the trail wondering what happened. Extreme conditions, for sure, and Shimano works hard so that you will never reach that dangerous point, but let's face it, any degradation of braking power and control will be noticed on long, hard downhill runs or gnarly descents. The use of 180mm and 203mm rotors indicates you expect such challenges, and yet things can get extreme. In their effort to do absolutely everything possible to reduce heat build-up, Shimano makes the J03A Resin with IceTech cooling fins. The fins act as a radiator, allowing cooling in and around the pads, and releasing heat at the same time.

Resin pads have the advantage of staying as cool as any material, and combined with the aluminum backing plate and integrated fins, there is the top performing pad Shimano makes. Resin delivers sure, quiet stopping power in all conditions, with the caveat that it wears faster when wet. Many riders will chose sintered metal pads for excessively wet and muddy conditions, but others will stay with resin for the best feel and control.

Shimano developed the finned pad design along with IceTech, with the ultimate goal of combining fluid, caliper, pad set, and rotor technologies to reduce heat from disc braking. The J03A pads use a pin and carrier spring design with a center mount set-up. This finned pad may not be compatible with all center mount Shimano disc calipers, but if you want the same resin pad without the fins, opt for the G-series version. The fins add a little weight, important to gram conscious XC racers, but few others. If you ride 4+ inches of travel with Shimano XTR or XT disc brakes, and want the best overall disc brake performance possible, we highly recommend the SHIM J03A Resin Pad and Spring with Fin.