Question: what are fat bicycle tires for?
Answer: 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.