Eli5: Why do offroad bicycles have fatter tires while offroad motorcycles have skinnier tires?

Question

Eli5: Why do offroad bicycles have fatter tires while offroad motorcycles have skinnier tires?

In: 17

Answer 1

Thin, light-weight tyres are more efficient because there’s less weight to carry around and they cause less wind resistance. On hard surfaces they have less rolling resistance too. There’s an advantage to having the thinnest practical tyres and so road racing tyres are pretty extreme. Everyday cyclists want a little more comfort and less maintenance so their tyres are larger.

Off-road the problem is often that thin tyres will sink into soft terrain and so be actually less efficient. Also, thin tyres with the necessary very-high tyre pressures can’t absorb bumps in the surface and, not only can this make for a very rough ride, it will lead to failures of the tyres, wheels and other parts of the bike.