So my 9spd stuff is wearing out, so it might be time to upgrade…

Starting at the front, what will work and what needs replacing?
New 11spd shifter needed, obvs.
Chainrings are 10spd.
Front mech, currently 9spd.
9spd chain will be replaced, but is there any difference?
New cassette needed, obvs.
New derailier to be fitted cos mine is end of life.
What about the rear wheel / freehub on a 135OL Qr hub (Hope pro 2)?

Oh, and have Shimano changed the cable pull ratio of mech and shifters? I used to prefer the 1:1 ratio of Sram as it seemed more tolerant of sticky cables. Have Shimano changed their cable pull ratios for 10spd or 11spd?

I doubt a 9 speed chain set / mech will play nicely with 11 speed rings. The chain is a lot narrower.

You’re probably looking at a full group set minus brakes.

Shimano did change their cable pull with the switch to 10sp (which is why it’s possible to use a 9sp MTB mech with 10sp road shifters, but not a 10sp MTB mech).

I think an 11sp cassette is the same width as a 9sp one. SRAM 11sp needs a new free hub body.

Shifter, mech, chain, cassette, narrow-wide ring on existing chainset.

New 11spd shifter needed – Yep
Chainrings are 10spd – Probably fine…. but I’d be tempted to go 1x with a Narrow/Wide ring
Front mech, currently 9spd – if you’re sticking with a triple, probably ok, but as abiove, I’d ditch it
9spd chain will be replaced, but is there any difference? – Yes, different width, needs replacing
New cassette needed, obvs – Yep
New derailier to be fitted cos mine is end of life – Yep, will have to be 11sp, cable pull did change
What about the rear wheel / freehub on a 135OL Qr hub (Hope pro 2)? Same freebhub for Shimano 11s cassettes, different freehub for SRAM 11s cassettes (but even the cheap ones are lighter and wider range than XT)

The whole point of 11 (as I see it) is to be able to go 1x. If those ratios don’t work for you, it might be worth considering whether 3x something (or at least 2x) is still the best option. 9 speed will be around for a while, at least the lifetime of a fresh drivetrain.

Sorry, should have said. I run 2×9, and will be going for the smallest 11spd cassette to get tight ratios 2×11.

Chain, cassette, shifter and mech are all on their way out, so 11spd seems like a reasonable choice if I don’t need a new wheel.

Unless Shimano don’t offer an 11spd cassette smaller than 11-40t, which is pretty big for 2×11. Their road cassette 11-32 would be better (same range as I have at the moment), but I dont think that will fit my freewheel.

So maybe I like the sram ratios better, but that will need a new freewheel – can I even get one for my hub?

No, doesn’t look like I can get an xD driver for a pro 2 (not evo).

So, unless I’m mistaken, I can have 11-40t Shimano 11spd, or it’s a new rear wheel. Will a new car rear hub allow me to run a road cassette?

Hmmm. Looking at the ratios I might be ok on 32t x 11-42t 1x11spd… Or maybe I should just look at 10spd?

Can I run 11spd road cassettes?

https://www.merlincycles.com/shimano-xt-m8000-1-x-11-disc-brake-groupset-87447.html

No, doesn’t look like I can get an xD driver for a pro 2 (not evo).

You can you just need to do the internals too. (make it a 2 evo)
Xt 11sp is very heavy for a 2x compared to any 10sp. The 10-42 gives a big range