Replacing brake & shifter housings on AMP Alpenchallenge

[dougpnirv]

I've recently purchased a 2021 BMC AMP Alpenchallenge City One. Due to old age, I've replaced the stem & bars to allow a more upright riding position. However, this has also eliminated what little slack there was in the rear brake & shifter cable. I would like to install longer housings. The shop where I purchased it seems not too keen on the idea, and one other shop said they'd expect to have to drop the motor. It looks like it would be PITA to do, so I'm willing to pay to have it done right the first time. I can think of a couple of simple procedures involving using a tag line to pull the parts into place, nothing exotic. Am I missing something? Do they know something about what's inside the frame that is a fatal flaw? I assume the shifter cable housing is full length. Does anyone have direct experience with this process?

Looking forward to hearing user experiences on this question.

 

[geysir]

an old thread...but I will respond anyway.
I have replaced housings and found it not too difficult for a novice.
Yes, the shifter cable housing is full length.
Dropping the motor is trivial. I don't know about this motor but usually you can remove all but one screw and let the motor swing down.
As for installing a longer cable housing, I would:
(1) lower the motor (if necessary). Remove enough screws so motor can swing down.
(2) Undo the screw holding the cable to the derailleur and pull out the old cable
(3) Insert a new, longer cable into the cable housing from the rear (backwards) so the pointy end comes out by the handlebars.
(4) Remove any end pieces on the old housing. Remove any clips, zip ties, or tie-downs holding the old housing.
(5) Carefully remove the old housing, pulling toward the front, handlebar, end of the bike. Be careful the cable stays in place.
(6) From the front end, insert your new housing onto the cable and work it into place.
(7) Pull out the cable and insert it correctly from the handlebar area.

note:
you need a new cable longer than the new housing
I use a new cable for installing the housing so that there is no kink or loose wires.
I installed the new housing front to rear because the rear section was the most difficult to navigate on my Yamaha.
You probably can: pull out the old cable, insert a new cable in the correct front-to-rear-direction, pull the old housing out the rear, and install the new longer housing from the rear, pushing it up to the front.