SHIMANO Di2 SM-JC41 B Junction Box (Internal) Complete Road Bike Each bearing can be removed

Each bearing can be removed and replaced using standard bearing tools

than a mid-depth carbon wheel

The vulcanized rubber top is practically indestructible

Mark XS S M L XL S1 490 510 540 560 590 S 447 467 497 517 547 T1 510 520 539 560 580 T 504 514 530 549 570 H/T 100 120 140 160 180 a° 70

Integrated low-profile caliper design

SHIMANO Di2 SM-JC41 B Junction Box (Internal) Complete Road Bike Each bearing can be removedSM JC41 SHIMANO Junction B E TUBE Internal DI2 Wire Routing 4 Port For 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.