While spandex cycling shorts aren't really all that popular in the mountain bike scene, it's tough to argue against the benefits of a stretch short with a padded insert. Since aerodynamics really don't make much of a difference to the gravity crowd, a padded liner is the answer. You still get all the benefits of a stretchy short and padded insert, but you strutting your stuff for all the world to see isn't a requirement. The folks at Alpinestars have been designing gear for dirt junkies for about 50 years now, and they know more than just about anyone what will help a mountain biker get to the bottom first. The Alpinestars MTB Inner Short is specifically designed to be worn underneath your baggies. Alpinestars included snap fasteners to lock the Inner Short into their Alpinestars baggies, but it can be worn under any brand of short. You can also wear the Inner Short under jeans, walk shorts, board shorts, or a tutu not recommended. The Inner Short's main body fabric is a synthetic that breathes well and draws moisture away from your skin. The short is anatomically designed for a close to skin fit. Alpinestars incorporated its EVO insert to help manage moisture and provide cushion.