The Shimano Dura-Ace BB-7710 Track Bottom Bracket is the perfect match for the Dura-Ace FC-7710 Track Crank. The Octalink bottom bracket has been designed to withstand the sort of power output that comes with serious track racing. The splined ends contribute to a more rigid interface with the crank, resulting in an extremely durable and flex-resistant unit. Contributing to that rigidity, a compound bearing structure is employed, working with both ball and needle bearings, in order to support the spindle, reducing potential flex. The structure works because the two types of bearings excel in two different situations, with needle bearings best handling radial loads while ball bearings pick up the slack when there is a degree of axial loading.
The chrome-moly steel axle is 109.5mm in length. The Shimano Dura-Ace BB-7710 Track Bottom Bracket comes in a 68mm BSA. Intended for use only with the Shimano Dura-Ace FC-7710 Track Crank. It weighs in at 173 grams.