ENVE's M6 line of wheels are the definitive mountain biker's wheelset, and it brings lightweight and super versatile wheelsets bridging the gap between cross country racing and all-mountain riding, in the super competitive segment of the market known as trail. The wheels perfectly meld the speed and performance needed for spirited riding while providing plenty of backbone for superior durability and abuse. Taking the attributes of everything we loved from that lineup, ENVE introduces the M640 29-inch Boost Wheelset, allowing you to enjoy the incredible traction that can only come from the marshmallow soft plus size tires in a package that ensures you still have that coveted ENVE ride.The 29-inch M640 rim weighs in at 485g, which is pretty impressive given the wheels intended trail use on bikes up to 160mm of travel and the fact that it has to provide a excellent tubeless seal and support the extra leverage that comes from running 2. 7 through 3. 2-inch tires run at very low pressures. A good chunk of the weight savings comes from the wide hookless beads. They're lighter and offer better impact resistant for the rim against the trail and an excellent buffer for the tire, preventing pinch flats while running low tire pressures. That 40mm wide internal rim width is solely optimized for plus size tires and it helps achieve a rounder tire profile translating to greater cornering stability and more rubber on the ground at any given time.ENVE spent many hours in the lab and on the trail ensuring that the ride of the M640 was classic ENVE. Anyone who's familiar with ENVE knows the fanatical lengths that its engineers go to in order to achieve a perfect ride feel. As with its narrower siblings, the M640 Plus has been tuned to provide a great degree of vertical compliance, which reduces rider fatigue, without sacrificing the fantastic lateral rigidity that endows ENVE with the "on rails" feeling for which they're prized, especially important with those plush plus tires....