The Shimano BB-RS501 is a Hollowtech II threaded bottom bracket for 68mm BSA road frames.

• Fits 68mm BSA (English-threaded) shells
• For Hollowtech II cranks with a 24mm spindle
• Strong, light anodised aluminium cups
• Better seals for longer service life
• Approx. 93g
• Fits cranksets such as Tiagra FC-4700 and GRX FC-RX600