Disc Brake Rotor Shimano SM-RT66 SLX 6-Bolt 180mm Disc Brake Rotor Shimano SM-RT66 SLX 6-Bolt 180mmGenuine Shimano disc brake rotors give the very best performance with low wear and quiet operation. The Bicycle Depot Technical Top Tip: Keep your greasy fingers and any lubricants or sprays well away from your brake rotors and pads. The most common cause of poor braking performance and especially of noisy brakes is contaminated pads. The solution is to check there are no brake fluid leaks, and then clean the rotor very thoroughly with hot soapy water and then isopropyl alcohol, and fit new pads. If unsure, seek assistance from a professional bicycle mechanic.