Shimano is one of the few manufacturers who has yet to embrace a 30 mm bottom bracket spindle standard, and for BB30 frame owners who wish to equip Shimano cranksets, this creates a compatibility problem. With their BB30 bottom bracket reducers sleeves, HSC presents a simple solution to this problem. These CNC machined reducers lightly press into existing BB30 or PF30 bottom bracket bearings, simultaneously widening the bottom bracket and reducing the spindle interface, to allow full compatibility with Shimano Hollowtech II cranksets. Reducers are available in either delrin plastic or 6061 aluminum.
These reducers contain no bearings and merely retrofit an existing bottom bracket; an alternative solution for frames without bottom bracket bearings installed is an HSC BB30 Adapter Bottom Bracket. Feel free to contact us directly for technical questions.
No special tools are required to install the reducer shims; they can be easily pressed in by hand.