The WH-R501 is the perfect entry-level wheelset with proven Shimano quality. It features a stable aluminum rim with a 24 mm profile, 20 stainless steel spokes in the front, and 24 in the rear, both the rim and spokes are black. The wear indicator allows for timely replacement of the rim. Shimano also uses exclusively angular contact ball bearings in the WH-R501 wheels, which can withstand lateral forces. The asymmetric rim increases the load capacity of the rear wheel. The asymmetry of the rear rim allows for a less steep angle of the drive-side spokes and a more uniform tension of the spokes, making the wheel significantly more stable.