Finding it unreasonably difficult to replace the front mech cable on my 2017 Arkose 4.

Removing the original Jagwire cables (they’ve lasted well), the thin plastic cable outer that you see under the bototm bracket snagged on the PTFE cable coating when I tried to pull through, so I had to throw it away.

“Oh well”, i thought. I have other bikes with similar routing and they don’t have that plastic outer. Must be a Jagwire thing.

Now I’ve tried to set up the front mech, I can’t seem to get enough tension on the cable to change up into the big ring. I’m doing the usual – drop into small ring, pull cable with pliers, tighten bolt.

So I guess:
1. Is that plastic outer important? And if so, what’s it called / where can I get more?
2. I just poked the replacement cable through the downtube until it came out the bottom. Could it have caught on something in there? I suppose in theory it could be wrapped around the rear mech cable / brake hose which is giving it extra slack when I change gear. It doesn’t feel that way though.

Any other ideas gratefully received. Bike fettling time is at a premium (small child!).

You need to follow the Shimano instructions, you can get them on the tech docs, roughly;

You wind in the L limit screw until the outer mech plate is in line with the big chainring, then clamp the cable, set the L limit and fine tune with the inline barrel adjuster.

A bit fiddly and annoying if you are used to traditional mechs.

Some bikes really need liner cable, some are fine without.

is there an inline adjuster fitted?

doing the usual – drop into small ring, pull cable with pliers, tighten bolt.

Sadly not how it’s done anymore… See bigyan post

Ah, thank you – didn’t realise the process had changed! Many thanks to the two of you who have pointed this out.

Will have another go tomorrow.

Have ordered some of these in case I end up needing a liner:
https://www.evanscycles.com/nokon-teflon-liner-2m-x-1-3mm-EV190700

Cheers,
Tom