The Endless Arc 165 5-Wheel Frames are precision machined for 5-wheel blading fun with multiple configuration options. They hold a max configuration of 84mm wheels on each end with 3x76mm wheels in the middle. If you size down a little bit to 80mm wheels on both ends, it allows the rocker-able axles to be used to their fullest potential. The extra pivot point (middle wheel) allows for an advanced wheel rocker and they are extremely stable, but still highly maneuverable. Endless recommends using wheels with the same profile for the best results.