The Silica technology increases durability up to 20% than Starcross 5 and helps maintain tread block integrity over the life of the tire The adaptive design provides up to 15% than Starcross 5 more traction Tread blocks resist irregular wear for better traction Double ply carcass (2 layers crossed at 90 degrees) This dirtbike tire is speed rated M for speeds up to 81mph This dirtbike tire is Tube type Available in the following dirtbike tire sizes: 100/90-19 and 110/90-19