Fat tyres range from 3.7-4.8" on 50-100 mm-wide rims, which allow unprecedented amounts of flotation and the capacity to operate at variable pressures. Lower pressures increase the footprint of the tyre, providing increased surface area like a snowshoe or backcountry ski. Flotation is essential to the genesis of the entire genre, whose early history is credited to pioneering cyclists in Alaska and New Mexico looking for solutions to ride on