Ready to upgrade your bottom bracket? Kogel T47 Internal Corrosion Resistant Bottom Brackets have you covered. These Ceramic BBs will fit any specified crankset on a T47 frame with 86.5 or 85.5mm wide shell with options for on or off-road bikes. Now made with Kogel CR bearings the result of two years of development yielding a custom race that combines the hard wearing nature of Chrome Steel with the rust-proof qualities of Stainless steel.