While mountain bikes have long been called fat-tire bikes, a recent article on BostonGlobe.com reports that a new generation of mountain bikes is taking the concept of “fat tires” to an entirely different level. These “fat bikes,” equipped with either 26-inch or 29-inch wheels, feature tires ranging in diameter from 3.5 to 5 inches that work equally well on sandy beaches and snowy trails.
The fat bike’s low tire pressure results in a cushioning effect that helps it ride over difficult terrain. Road tires will typically run between 100 and 125 pounds per square inch, or PSI, and mountain bikes range between 25 and 60 PSI (depending on terrain and suspension choice). Fat bike riders, however, typically run their tires with less than 10 PSI, giving them plenty of bounce.