Tarmac SL6 and shimano jc41 (junction B)

[floppyb]

I'm trying to upgrade my Tarmac SL6 to Di2, but Im running into trouble fitting the junction box B (sm-jc41) into my bottom bracket. I can't for the life figure out how to get it in with taking a hammer and smashing it in. What am I doing wrong? The bottom bracket hole just does not seem big enough with the bottom bracket shell in the way.

[joevers]

You gotta take the bottom bracket out. You should be able to connect all the wires to the b junction outside the bottom bracket, then firmly push it up into the seat tube, tuck the wires out of the way, and reinstall the (hopefully sleeved) bottom bracket.

[floppyb]

Ah. Was hoping to avoid that removal.

There is some type of sleeve or shell in-between the standard pressfit bearings. Is that part removable as well?

[P K]

Just pull a bearing on one side, the sleeve comes out, and you can hide that B junction in the down tube or seat tube.

careful pulling and re-installing bearing, keep the bearing straight, use a BB press

[joevers]

Originally Posted by floppyb

Ah. Was hoping to avoid that removal.

There is some type of sleeve or shell in-between the standard pressfit bearings. Is that part removable as well?

Yeah, that part will come out once you get one side of the BB out. It's great that your bottom bracket has that because it makes di2 wiring much more problem-free in the end since there's no chance of the etube wires accidentally touching your spindle.