fat bike

plural fat bikes · alternative fatbike

1. winter sportscyclingA bicycle equipped with larger than normal tyres and a wider frame to accommodate them, which provides better traction on off-road surfaces such as sand or snow.

   1 more example

   Those favoured by teens are also known as fatbikes due to the thick tyres meant for tackling sand and off-road terrain, and are often illegally modified to allow them to travel at far greater speeds than the 25km/h limit for e-bikes. […] Food delivery riders on fatbikes are also a source of frustration for many Sydneysiders.

   2026 March 6, Helen Livingstone, “Fatbikes are wreaking havoc in Sydney's wealthy beach suburbs”, in BBC