Externally routing cables on Trek Allant 7.4 How would I externally route the rear gear cabling on a Trek Allant 7.4?
It's had problems down shifting ever since I had the shifters replaced that can't seem to be repaired (Internal Cabling Problem?)
I'd like to convert it to an mid drive e-bike if I can get it to shift properly and afaik the motor I'm looking at can't be used along with cabling under the bottom bracket.
There's a cable entry point on the side of the down tube from the shifter, internal (no housing) cable lines under the bottom bracket, and an exit around the back of the chainstay.
Assuming you have no cable stops on the outside of the frame, you'll need to use full housing all the way from shifter to derailleur.  Simply run it alongside the top tube and down the right seat stay, and secure the housing to the frame with cable ties.
Its not the prettiest solution, but you're strapping on a motor, battery, controller, and wiring on anyway so looks are already going to suffer.
If cable ties aren't your thing, there used to be brackets for the top tube which would hold a rear brake cable on 80s style road bikes, or you could buy pairs of clamp-on cable stops of suitable size.