Hayes Stroker Trail/Carbon/Gram Brake Pads- Sintered Metallic Replacement disc brake pads for the Hayes Stroker Ace brake system. In 1997, they changed the face of mountain biking forever with the first viable hydraulic disc braking system—the Hayes Mag. The Mag was a good start and has continued to set the design standard for most brake offerings today.Hayes has continuously refined their braking systems on the performance demands of riders and the need for reliability and serviceability. Their range now includes hydraulic & mechanical disc brakes, rotors and disc pads.