SRAM 12 speed set up - chain skipping

[Ajax Bay]

Given this bike has internal cables, the choice of any cable outer will need to take that into account. Inners are, essentially, all the same (obv must be stainless steel not cr@p) - the head needs to be 'the same' as now.

 

[peter-h]

So do you extract the cable from whatever the bike is, buy a generic sleeve, and chop that up to match the old pieces?

 

[Ajax Bay]

Internal cabling - the devil's work. But aesthetically beneficial and aero advantage.
If you're going to attempt this, invest time in youtube viewing to help you start with confidence.