Among the new bottom bracket standards in the bike industry is BB86. It offers frame designers a little more room for new designs in seat/down tubes and chainstays. Where a typical road bike has a 68 or 70mm bottom bracket shell width, a BB86 equipped bike has a shell that measures 86.5mm wide. A BB86 shell lacks internal threads and has a 41mm inside diameter.This Shimano BB86 Bottom Bracket Assembly is made to press right into your bike. It will mate your Shimano HollowTech crankset to any frame equipped with a BB86 bottom bracket shell. Frames that use BB86 bottom brackets include bikes from Scott, Giant, and plenty of others. This bottom bracket comes with two steel cartridge bearings pressed into composite cups. The cups increase the outside diameter of the assembly to 41mm to match the i.d. of the frame's bottom bracket shell. There is a 1.75mm thick outer lip that provides a positive stop for the cups when you press them into place. Shimano includes their standard plastic o-ringed inner sleeve to protect against water damage should it find a way inside your frame. It uses black plastic dust shields that snap into the inner race of each bearing.