A fatbike is a bicycle with over-sized tires, typically 3.7" or larger and rims wider than 44mm, that are designed for riding on soft unstable terrain such as snow and sand. These bikes are built around frames with large forks and stays to accommodate the wide rims required to fit these tires.
Fatbikes were invented for winter trail riding and racing in sub-arctic Alaska and simultaneously, for touring the deserts of New Mexico. Their use includes snow, sand, desert, bogs and mud as well as riding what is considered normal mountain biking.
The original fatbikes were normal mountain bikes equipped with the SnowCat rims, created by Simon Rakower of All-Weather Sports in Fairbanks, Alaska. Simon was involved with technical support aspects of the Iditabike (later IditaSport) race, which started in 1987. He started hand making extra wide rims for participants by welding two rims together and cutting off the middle ridge. Enthusiasts would cut and sew tire-carcasses together to maximize the size of the tire and utilize all the available space between the seatstays and chainstays; this tire and rim combination would maximize the bicycles footprint, increasing flotation on winter trails. Soon after, Simon decided to design a 44 mm rim from scratch and had it produced. SnowCats revolutionized winter cycling as they could be fitted to nearly any commercially available mountain bike.
At the time frame builders were experimenting with custom components and configurations designed to achieve a large contact patch of tire on snow. Simultaneously, in New Mexico, Ray Molina had commissioned 80mm rims, 3.5" tires and frames to fit them. He wanted the bikes for his guided desert tour business; the soft-sand of the arroyos. Rims and tires were imported to Alaska where frame builders began making small, handmade, production runs and custom-ordered frames built around the 80mm rims and 3.5" tires. Surly Bikes released the Pugsley frame, in 2005, Large marge rims and Endomorph tires. The Pugsley frame, rim and tire offerings made fatbikes commercially available in local bike shops world-wide. Other bike manufacturers have also entered this market, including Trek with the Farley, Salsa with the Beargrease, and Specialized with the Fatboy. And On-One with the Fatty who have also launched the world's first ever 24" Fat Bike called the Baby Fatty.
In December 2012 Eric Larsen (Polar Explorer) attempted to ride a fat bike to the South Pole. He made it a quarter of the way before he had to turn around. In 2013/2014 there were three cycling expeditions to the South Pole. Maria Leijerstam became the first to cycle to the South Pole. She rode a tricycle with fat bike tires. Juan Menéndez Granados skied and rode a fat bike to the South Pole. On 21 January 2014 Daniel P. Burton became the first person to ride a bike across Antarctica to the South Pole. Burton started at Hercules Inlet, and biked 775 miles to the South Pole. He rode on a carbon fiber Borealis Yampa fat bike with 4.8 inch wide tires.
- Adam Fisher. "Rollin’ Large". Bicycling. Retrieved 2014-01-18.
- Fat Bike Best Practices. Surface604.com. 2014. Retrieved 9 April 2014.
- SnowCat page on All-Weather Sports website
- Pugsley on Surly website
- Farley on Trek website
- Beargrease on Salsa website
- Fatboy on Specialized website
- The Fatty on the On-One website
- Baby Fatty on the On-One website