The Teamster Bike Short is our Trail short. At a 22" Outseam it is cut at or just above the knee for most riders. This short is great for long XC rides, with a rear stretch yoke, side pockets and waist adjustment it is comfortable and cool in hot weather. The 4-ply nylon is tough, but light and malleable enough to easily move with your body.
The Longhaul Short is our gravity oriented mountain bike short. It sits 2" longer than the Teamster, but still designed for pedaling with knee pads. On most mountain bike riders the shorts sit just below the knee. The Longhaul short is a little bit heavier duty than the Teamster and includes with a mesh liner (no chamois). The outer short material is the same: 4-ply nylon and also includes a few more gusseted panels for extra strength. This short is popular in Enduro riding, All-Mountain riding, and great for shuttle runs. The 4-ply nylon makes it easy, light and pliable for easy movement, but strong enough for the rigors of downhill riding. With that said we got an email the other day from a customer saying they pedaled 4,000 feet vertical in the Longhaul.
It really comes down to the type of mountain bike riding you are into and what makes you most comfortable. Many customers order both, which gives the option to choose the tool that best suits the bike ride your headed too.