i’ve got the first component of my 10speed upgrade in the form of a Zee front shifter.
i’ll now be looking for a rear mech and cassette but i’m kind of stuck with this and need some advise…
ideally i will start off by running a 2×10 setup before moving to a 1×10
my current 8 speed cassette is 11-30 which is now useless for climbing and i’d like to go to 11-36 with the new cassette
but looking online it seems the only rear mech i can use for this cassette is a long cage unit and ideally i would like to use a medium cage unit (but they only apparently work up to a max of 35t)
it seems the only option is to run a zee rear mech which can accomodate 11-36 using a shorter cage.
do i have to bite the bullet and accept using a long cage unit or can i get away with medium cage unit?

thanks in advance

The 35t refers to the total teeth difference between the front rings and the difference over the cassette I think.
So, 1×10 running a 11-36 cassette would just be 36 – 11 = 25t
If you had a 22 and 36 front rings, that would add 36 – 22 = 14t making a total of 25t + 14t = 39t.

So in theory you need a long cage but if you never use the smallest ring to smallest sprocket and size the chain for the largest combo, you should be OK. Or at least that’s what I’m hoping as I’m planning on doing similar.

Get a Deore Shadow + long cage and you’ll be fine. Ribble are normally dirt cheap.

ribble only do road bike stuff….do you mean merlin?

i contacted merlin for some advice on this and this is what they had to say..

I wanted to ask about compatibility of shimano drivetrain components. I am in the process of upgrading my current transmission to 10speed and would like to know if it would be possible to run a 11-36 cassette with a medium cage (GS) rear mech or would I need to use a long cage (SGS) unit?
Initially I will be running a 2×10 setup but will then go to 1×10 so ideally I would like to use a medium cage rear mech. Any advise on this would be gratefully appreciated.

p.s.
I’m not too bothered about the rear mech being a clutch unit as I am also running a front chain device and will go to a narrow/wide ring when I go to 1×10.

their response was…

Shimano will only advise to use the same groupset components with each other, so whilst it may be possible to run those ratios it would be with a mixture of components which unfortunately we cannot advise.

ehhh??? about as clear as mud!!