Marin Alpine Trail XR Full Suspension Mountain BikeMarin Alpine Trail XR Full Suspension Mountain Bike The Alpine Trail series is Marin's boldest and most capable line of enduro bikes ever, built upon their most advanced, most adjustable frames to date. Series 4 aluminium MultiTrac 2 LT frames feature mixed 29 27. 5 wheels, 170mm front and 160mm rear travel, and the utmost in adjustability. Riders can alter the head tube angle and bottom bracket chainstay length, as well as run 29 rear wheels if