You can do it yourself, just ensure a tidy radius when cutting the housing length, ensure both end are cut smoothly (dremel if necessary), push cable in both end and wiggle it to widen the plastic internal coat, then run cable through to ensure there's no friction whatsoever.
When done, install cable on bike making sure both end cap is pressed in frimly, lubicated the cable a tiny bits with chain oil.
When attaching cable, tighten bolt and really give the levers a very hard squeeze to ensure the housing is properly compressed (even with compressionless, it's worth doing).
Jagwire also do compressionless for like £35 including shift and brake cable/housing.
You can do it yourself, just ensure a tidy radius when cutting the housing length, ensure both end are cut smoothly (dremel if necessary), push cable in both end and wiggle it to widen the plastic internal coat, then run cable through to ensure there's no friction whatsoever.
When done, install cable on bike making sure both end cap is pressed in frimly, lubicated the cable a tiny bits with chain oil.
When attaching cable, tighten bolt and really give the levers a very hard squeeze to ensure the housing is properly compressed (even with compressionless, it's worth doing).
Jagwire also do compressionless for like £35 including shift and brake cable/housing.