The stock 90mm wheels and ILQ-9 bearings on the men's K2 Mach 90 roll smooth over any terrain. The full cuff and high ankle lacing provide maximum stability and support. The Mach 90 has remained K2's best selling fitness skate five years running. Formerly known as the V02 Max, and essentially the same design, this skate has changed colors each year, but has remained the favorite of fitness skating enthusiasts world wide. It is built and priced for those who want a solid and reliable performance skate that will last for year of heart pounding fitness skating. The major differences between this skate and the K2 Mach 100, aside from the paint job, are the wheel base and frame. Although the boots fit the same, the Mach 90 measures 37mm from front wheel tip to rear wheel tip where as the Mach 100 measures  41.5. This is achieved by squeezing the Mach 90's smaller 90mm wheels tightly together in the frame. This results in higher maneuverability, which comes in handy when doing cross-overs or backwards cross-overs.