maartendc

Hello all,

I'm looking for some advice on replacing shifter cables (Sram Force) on a BMC frame with internal cable routing, which I have never done before: I want to do it myself in order to learn how to service my entire bike.

1. Does it make sense to replace the shifter cables without also changing the housing? Or do you always replace both at the same time?
2. I am planning to use the method with a thin "cable liner" or "housing liner" to guide over my old cable, and then guide the new cable through the internal routing in the frame using this method: https://www.artscyclery.com/learning...tedcables.html
Planning to buy this liner for it: https://www.amazon.com/gp/product/B0...AVQ4OOHG&psc=1. Anyone know of a better method or liner?
3. Are you supposed to re-use the barrel adjusters at the ends of the cable housings? Or do you replace those?
4. Any other tips / tricks to look out for?

Thank you!

Andrew R Stewart 

Sorry to hear that you have internal routing

1- As internal routing is a pain to deal with and that the casing does wear too I strongly replacing both at the same time.
2- The liner over the existing inner cable is the first method I go to. Only when it doesn't work would I have to use a more frustrating one.
3- Always have a barrel adjuster in a cable path. Unless they are damaged/rusted I would clean them up. lube the threading/spring and reuse.
4- Use SS inners. Use uncoated inners. Use new casing end caps. Do double check the adjustments and alignments of the ders after.

Andy

dsbrantjr

I replace both the inners and outers at the same time, my reasoning being that the inner wears into the outer (a major contributor to "stretch") and a new inner may not play well with the existing groove.
Agree with Andrew Stewart's cable choices, I use die-slicked/drawn inners. I use the tiny dab of lube which comes on Shimano housings, or none if not supplied. It is tough to find a lube which improves on steel vs PTFE's (Teflon) coefficient of friction of ~0.05.

Le Mechanic

I made a video about a year ago with some tips as well as potential issues to avoid, but yeah, you should generally replace the housing when replacing the inner wires.

JoeTBM 

I have replaced a number of internally routed housings.
Best is before you put out the old housing, attach a strong piece of string or cord with electrical tape. This will help you snake back in the new housing by taping it to the string. It is important to feed the new housing in as you pull the string. If you lose the string you are going to have to snake it.

Me.... I'm a retired electrician, that is why I use this trick.

HillRider

The worst internally routed cable I ever had to deal with was a late '80's Trek 560 where the rear shift cable was routed internally through the drive-side chainstay. There was no housing used, just the inner wire. There had been an internal guide funnel at the exit end but that had come loose as these frames were prone to do. It must have taken a half hour of trial and error and profanity before I lucked into the exit hole. I quickly learned to use the old cable to guide the new one through for future recabling.

Retro Grouch 

Use the old cable housing to guide the new inner shift cable through the frame. Then pull out the old cable housing and use the new cable to guide the new cable housing.

My other trick is to figure out how to position the bike so that I can see the cable outlet and it's right right at the bottom. Then I push the cable through and watch as it comes past the exit hole. Then I snag it with something and pull it through. This has always been easier to do than it sounds. The most time consuming part is figuring how to position and clamp the bike so I can see the exit hole.

justridingalong

I'm replacing a rear shifter so a new cable is required. I've seen videos that use tubing with a i.d. that slightly larger than the cable as a guide, magnets, thread fastened to cable, a vacuum. I think I'm going to remove the bottom bracket and have a look into the shell, then make my decision. Right now I'm considering fishing line connected to the end of the cable for removal and installing a new cable. I'll post my results in case I can help others. Unless there's something wrong with a barrel adj. I'd leave it. Replacing housing is recommended. I'll check that Amazon liner out.

maartendc

Just FYI, I used that liner cable from Amazon, worked absolutely perfectly!

The inner diameter is just ever so slightly larger than the shifter or brake cable. You just slide it over the old cable, through the frame. Then, slide out the old cable, and slide in the new cable. Very easy, and no risk of the cable getting lost at any point.

I would definitely use this method again in the future, and not bother with any other method.

Retro Grouch 

but it took you 8 months!

justridingalong

I ordered some Jagwire Black Housing Liner like you recommended, that seems to be the best solution for running cables through the frame.

maartendc

Lol, yeah! I'm a bit slow..

fietsbob

use Magnets (as long as frame is not steel, or cable is non ferrous stainless.. )

justridingalong

Turns out that there is an internal tube running from the down tube to the chainstay on my bike for the cable- good deal