Shimano SM-JC41 Di2 Internal Junction B Box Groupe 28mm and 32mm options

28mm and 32mm options

Specifically designed for installing 22mm / 24mm spindle diameter cranks (SRAM / Truvativ GXP) in BB30A (42mm ID

and upper tube strong enough to withstand 325 foot-lbs of torque

Carbon fiber is the ideal material for a gravity bar because fiber orientation and bar shape can be controlled independently and developed in unison

accurate front shifts

Shimano SM-JC41 Di2 Internal Junction B Box Groupe 28mm and 32mm optionsFor internal DI2 wire routing, SHIMANO's SM JC41 Junction B is the central connector for DI2 systems. Wires from the front and rear derailleurs, cockpit area, and battery all plug into the 4 port SM JC41 junction, which is housed inside the bike frame. Specifications For internal wire routing Mfr Claimed Weight 4. 1g