Shimano SM-JC41 Di2 Internal Frame Junction Box 4-Port Spring Weight-640 there will be some bikes

there will be some bikes that need modifications or flat out won't work

3" Primary Color Black Thickness In mm 12mm Lock Type Key - Plus Bracket No

LEVER SALT "AM" brake lever

32mm installed diameter is perfect for most riders

and rides that just require more gear

Shimano SM-JC41 Di2 Internal Frame Junction Box 4-Port Spring Weight-640 there will be some bikesShimano Di2 Frame Junction BoxFrame Junction Box connects via SD50 E tube wires to four different points: front derailleur rear derailleur cockpit junction box and battery mount All Di2 components on the bicycle require the same firmware version. Using Di2 components with different firmware versions may cause malfunctions Use Di2 system checker to update component firmware from http: e tubeproject. shimano. com