And note that the E-Tube wire is flexible enough that any excess can just be tucked into whatever bar or frame section the wire is installed into, thus longer is OK.
Along with having some excess, Shimano recommends you make a loop of cable where it exits the shifter, tape and tuck it under the bar tape on EDIT: outside of the shifter on the part of the bar closer to the center of the bike. If you crash and the shifter gets knocked to the outside, good to have the excess as it will stay connected. If you make the connection tight to the shifter, it might come unplugged. That’s an annoying thing middle of a ride.
Last edited by Steve B.; 06-19-20 at 04:50 PM.