Shimano Dura Ace 7703 Octalink Bottom Bracket

This is an OCTALINK bottom bracket with an oversize 22mm diameter hollow pipe billet axle to reduce weight.
It has a 118.5mm chrome-moly steel spindle, an Aluminium adaptor, a 45mm chainline with stabiliser and is available with a 68 or 70mm shell.
It also has splined ends that provide a more rigid, non-loosening crank assembly and compound bearing structure, ball and needle bearings, that support the spindle to reduce flex.