The Arch MK4 rim is light enough to take XC racing but was born from research and testing on the Enduro World Series circuit, making it a great rim for anyone looking to improve both descending and climbing. Constructed of light and strong 6069 aluminum alloy, with a reinforced spoke bed and 28mm internal width ideal for 2.2-2.5 tires, the Arch MK4 can get you up the climbs easier and make the descent even better. Utilizing Stans patented Bead Socket Technology, combined with a stronger asymmetric design for balancing control and weight, the Arch MK4 your best choice for all-around riding.