The ZTR Arch EX 27.5” Rim from Stan’s No Tubes is now lighter, wider and even tougher than the original Arch rim. This rim, much like the ATR Alpha 340 and 400 features new BST (bead socket technology) construction which provides superior tubeless compatibility. The internal arch design provides durability and stiffness, two assets especially important for heavier riders. Although lightweight, the Arch EX can handle aggressive trail riding. Quite possibly the best rim for any situation. Inspire confidence in your ride with the ZTR Arch EX. Available in 28 or 32 hole.