Providing added stiffness and weight savings, the BB30 system is offered on a small, but increasing number of race-worthy road frames. The problem lies in compatibility with Shimano’s popular cranks, such as Ultegra and Dura-Ace. That’s where the Wheels Mfg BB30 Adapter For Shimano comes into play. This nifty solution fits Shimano road cranks to BB30-equipped frames, thanks to its two reducer sleeves that precisely press into the BB30’s bearings for wiggle and creak-free performance. Please note that this adapter works with all Shimano and Shimano-compatible road cranks with a 24-millimeter spindle.