I’ve been having trouble with my gears not changing down, and constantly have to shift twice to get them to move. I’ve replaced the inner and outer cable and it’s no different. Is it possible that the spring in my clutch rear mech has weakened causing this problem? Otherwise, can anyone recommend some super slippy gear cables such as haywire that they can swear by?
Cheers.

Indexing out, worn out mech spring, worn out cassete, bent mech/hanger.

Wot ‘e sez assuming you haven’t messed up the cutting of cable outers like I did once, took me ages to work out that’s what I’d done

Can only think it’s the spring then.
Indexing seems fine when it does eventually shift down, it just takes a while.
Don’t suppose for a minute I can just by a replacement spring? Might as well wait till it’s all worn out?

The spring being worn out is the least likely option.

Most likely just too much cable tension

what sort of state is the upper jockey wheel in?
Take the wheel out and shift up and down to check movemnt, then disconnect cable and move the mech by hand if you suspect the spring.

I’d wager it’s a bent hanger though.

Should have gone electric*.

Jockey wheel is a good shout. Too much play might mean it isn’t doing its job.

I know you’ve replaced the cable but is there anything potentially fouling it or restricting the inners movement – damaged ferrule or something?

If you have inner exposed (i.e. you are not running full outers) then try pulling the inner and seeing if the mech moves freely without using the shifter. If it does then then it may be a shifter problem. If it doesn’t then it is a cable/mech problem.

Something bent is the common cause for my issues, hanger or the mech itself.

Bent hanger dealings with a hanger alignment tool

How old is your cassette?

Cable drag somewhere defo

Sounds like worn chain and bscrew needs adjusting. Bent hanger should still hold it still. Get the upper jockeya tad closer to the cassette.

Could be grit in the mech pivots, try giving it a good blast with GT85 or similar them dribbling a tiny amount of oil into the pivots. Saved many a sticky mech doing this.

Cable drag, kinked the inner when fitting?

Disconnect cable, manually push/release mech through gear range, is it still sticking now?

I’ve had shops sell me new generic outers to use with Shimano inners and had dreadful cable drag. Now I don’t mix.

Most likely just too much cable tension

This