A 29-inch wheel refers to the diameter of a bicycle wheel, commonly used in mountain biking. These larger wheels provide better rolling efficiency over obstacles like rocks and roots, making them popular among off-road cyclists. The increased size also enhances stability and traction, allowing for smoother rides on rough terrain. In comparison to smaller wheels, such as 26-inch or 27.5-inch options, 29-inch wheels can cover more ground with each rotation. This feature is particularly beneficial for long-distance rides and competitive racing. However, they may be less maneuverable in tight spaces, which can be a consideration for some riders.