A fatbike (also called fat bike, fat tire, fat-tire bike, or snow bike) is an off-road bicycle with oversized tires, typically 3.8 in (97 mm) or larger and rims 2.16 in (55 mm) or wider, designed for low ground pressure to allow riding on soft, unstable terrain, such as snow, sand, bogs and mud. Fatbikes are built around frames with wide forks and stays to accommodate the wide rims required to fit these tires. The wide tires can be used with inflation pressures as low as 340 hPa; 0.34 bar (5 psi) to allow for a smooth ride over rough obstacles. A rating of 550–690 hPa; 0.55–0.69 bar (8–10 psi) is suitable for the majority of riders. Fatbikes were invented for use in snow and sand, but are capable of traversing diverse terrain types including snow, sand, desert, bogs, mud, pavement, or traditional mountain biking trails. The sport is sometimes referred to as fatbiking or fat-tire biking.