Behold: the 27.5+ version of Surly's popular, fast-rolling Knard tread pattern (bet you didn't see that coming!) Coming in at a hearty 27.5 x 3-inches it's designed for 35–50mm rims with a bead seat diameter of 584mm (27.5-inch). The 3-inch casing rolls out to 29-inch when inflated. That gives you all the benefits of a 29er, like more ground clearance and the increased ability to roll over obstacles better with a slightly wider footprint and some extra cush. The closely spaced low-blocks of the Knard tread grips well on multiple surface types but is most at home on dry rock and packed dirt.