29-inch wheels are larger bicycle wheels commonly found on mountain bikes. Their size provides better rolling efficiency over obstacles like rocks and roots, making them ideal for off-road trails. The increased diameter also enhances stability and traction, allowing for a smoother ride on uneven terrain. These wheels are often favored by riders who prioritize speed and control. However, they can be heavier and may not fit all bike frames. It's essential to consider the bike's geometry and intended use when choosing 29-inch wheels for optimal performance.