Wheels and tires
Fat-bike rims come in a range of sizes ranging from 65-mm to 100-mm wide. The wider rims allow the high-volume tires to spread out more increasing the contact area with the snow.
The Surly Large Marge was the original fat bike rim at 65-mm wide but several other companies such as Flattop and Vicious Cycles have entered the fat bike arena with their own rims, many of them wider than the Large Marge.
Surly makes a variety of different fat bike tires for different riding conditions. The sizes range from the Endomorph, which measure in at 3.7-inches wide, to the Big Fat Larry, which comes in at a whopping 4.7-inches wide.
Both the Endomorph and the Big Fat Larry come with a fairly shallow tread pattern ideal for snow and sand, but to complete the collection, Surly has also created other fat tires for people wanting to venture beyond snow and sand on their fat-bikes.
The Black Floyd, at 3.8-inches wide, is a nearly slick tire idea for rallying around on pavement or hard trails while the Nate, also 3.8-inches wide, has, according to Surly, a “shred-your-face-off, run-over-anything, kung fu grip knobby tread pattern.” The Nate can be seen on fat-bikes riding on a wide variety of terrain, including rocky, desert trails.