While the internal width of the standard model is already impressively wide, the M70 Thirty HV 27. 5in Boost Wheelset bumps the rim walls out even further. The internal width goes from 25 to an almost comical 36mm to allow for maximum volume while running 2. 4 and 2. 5in tires. This added volume combines with the outsized Boost hubs to make for a ride that's smoother, stiffer, and courtesy of ENVE's unrivaled carbon can do more lightweight and responsive on climbs than any DH inspired all mountain and park wheelset has any business being. But here it is. If it sounds too good to be true, we can only respond that riding is believing. The 27. 5in M70 Thirty rim weighs a claimed 453g, making it slightly heavier than its predecessor, ENVE's AM rim, but the payoff of a wider tire bed and more durability is well worth it. Part of the strength increase comes from trading in traditional bead hooks for a redesigned, hook less bead, which is both lighter and more impact resistant. The internal width on the HV model is so exaggerated that you can almost fit the non HV M70 Thirty rims inside of it. That means more tire volume for greater cornering stability and more rubber on the ground at any given time. The rim tells most of the story, but two facts are worth stating. First, they're hand built in Utah to exacting standards for the longevity you'd expect out of a class leading wheel system. Second, those big, bruising, Boost hubs make for stiffer tracking up front and yet more improvements in responsiveness out back. These wheels are almost never caught on the back foot, even while navigating sharp switchbacks. On a climb. Across rocks. The small engagement angle of DT Swiss' 240 hubs also help clear rocky cruxes and make for a wheelset that may very well outlast your next bike.