Dunlop Geomax AT81 Tires All-around performance plus higher levels of ruggedness for off-road racing and riding. Features AT81 rear tread block shape and distribution plus flexible knobs help the tire penetrate down through the surface dirt for extra traction across a broad range of off-road applications. Newly formulated high-wear-resistant rear tire compound offers enhanced chipping, tearing and wear appearance. Geomax AT81 rear tire carcass features two nylon plies. Lateral grooves on the shoulder knobs provide additional biting edges and also allow the knobs to be more flexible. Rear center blocks are arranged in-line to provide a larger contact patch for maximum traction. Dunlop's 'plush pad' recess design between tread blocks enhances compliance for bump absorption and ride comfort. Front tire construction includes two plies of nylon wrapped with a third ply of polyester for a strong base.