For some full-suspension frames, the benefit of a plush ride has been offset by the amount of unwanted flex that plagues the design. In recent years, manufacturers have gone to great lengths to stiffen rear triangles, and the 12x142mm rear axle has been a leap forward. For many full suspension designs, the extra stiffness of the thru-axle over a standard quick release provides a seat-of-the-pants difference in how the rear end behaves through heavy trail chatter or when standing hard on the pedals.The Shimano SLX 12x142mm Thru-Axle uses an aluminum axle shaft with a fluted nut on the right side and a quick-release-style tension lever on the left.