Originally Posted by
globecanvas
Success, I got the housing all the way from the seat tube to the back of the chainstay. I know a lot of the appeal of this project is just how tinkery it is.
I measured out all the wires:
shifters to A junction: 350x2
A junction to B junction: 1000
B junction to FD: 200
B junction to RD: 700
B junction to battery: 550
Those are best guess at the actual distances. I'm sure I should add something to each for safety margin. 50mm? 100mm? More?
BTW I used a borescope to help get the housing through. I use this tool about once every 2-3 years. Every time it is like "hey I have exactly the right tool for this!" and I am so glad I have it.
nice work. yep--perfect tool!
as for measurements....yes, those seem right. most peoples' b-junction will be in the DT whereas yours will likely end up in the ST (don't know that you'll be able to stuff that into the DT....nor should you bother; people only put it there as that is where the access point often is) so they might use a shorter DT cable.
the challenge you might face is this: unlike someone who has a hole near the BB shell where all the wires can exit, then you connect them to the b-junction and stuff it back in the DT near the BB shell, unless you drill that out (you probably won't/shouldn't), you'll have to get all the wires to exit the frame at a point where you CAN connect the b-junction.
the most logical thing would seem to be to have all wires exit at the top of the ST, then you connect the b-junction and stuff it back down. as a result, you might need a substantially longer RD & DT wire--basically you'd have to add the length of the ST to your measurement.
you could do some creative stuff to get around this (e.g., sink the DT wire and have something tied to the end so that after connecting it, you could pull it partially back out the top of the DT....but then if you ever have an issue the b-junction is not easily accessible.
if i were you, i'd probably go with something like this:
1400mm DT (longest available; after you connect the b-junction you could pull it out a bit as there is always slack between the DT & junction A)
350x2 for the shifters (common)
800 or 900 for the RD (i'd probably err on the longer side...maybe even 1000)
~550 for the FD
~350 for the battery
in case you are curious, the difference in weight between a 350mm wire and a 700mm wire is almost nothing--single digit grams. so, in this case i'd forego any effort to nail the length exactly right and instead overdo it.
for the DT wire, take into account the height & length of your stem and where the A junction will be. also keep in mind that you'll turn your bars.
for a typical 56cm specialized, i'll use:
2x350
1000 DT
800 battery (long, but when i pull the post for travel i like to have the cable hang out of the ST and not fall back in)
700 RD (b junction is ahead of the BB, so it has to go up, around, over, and down to get to the DT)
350 FD
a little extra length allows me to pull the b-junction out and have some room to work on the rare circumstance that i need to.