Maxxis CrossMark XC Mountain Bike Tyre The CrossMark XC Mountain Bike Tyre is the dramatic evolution of the XC racing tyre and features a nearly continuous centre ridge which flies on hard pack yet has enough spacing to grab wet roots and rocks. The CrossMark XC Mountain Bike Tyre has a slightly raised ridge of side knobs which offers cornering precision which offers exceptional control. Suitable Uses XC Hard pack XC Racing Rubber Compounds The most obvious and arguably most important part of a tire is the tread compound. By changing the amounts of various components of the rubber compound formulation- engineers can make two tires that look identical but perform differently. Below are some distinct characteristics of Maxixs' most popular compounds. 70a Long tread life Low Rolling Resistance 62a eXCeption Great Traction Low Rolling Resistance 60a MaxxPro Great Traction Minimal Impact on Tread Life 42a Super Tacky Awesome Grip Stable Knobs Prevent Squirm on Hard Pack 40a Slow Reezaay Located on outer surface of shoulder lugs on 3C Downhill tires Provides unparalleled grip while cornering and slow rebound technology Foldable Bead Foldable beads stay tight to the rim but are lighter weight and easier to transport. The bead will be created of an Aramid or Kevlar material. Threads Per Inch(TPI) The number of nylon threads that cross through one square inch of the tire’s casing. Only one ply of a dual ply casing is counted. Lower TPI gives better puncture and tear resistance- but is heavier. Higher TPI conforms more to the terrain- offering a smoother- more supple ride. It is also lighter weight.