So I’ve recently upgraded from 11x XT to 12x on my h/t Orange crush (27.5” wheels) and while the gears have been working fine (until today) I’ve been a little concerned at the clearance between the bottom of the mech and the ground – it’s about 1” above the rim at it’s most extended – I know I have 27.5” wheels but that still seems tight – any views from others running XT 12 or sram on 27.5 wheels?

Today I fell foul of lots of mud and the mech ploughing through said mud and completely clogging up the mech – it didn’t help that the mud then froze around the mech and chain and resulted in me being stuck in 1 gear for the rest of the ride!

Does sram perform any better in the mud ( it’s going to be around in this neck of the woods for some time!) and is the clearance any better/worse?

I’m probably (I hope) worrying about nothing but worth asking just in case!

Cheers

This is just fall out from cassettes with dinner plate sized cogs.

Try shortening the chain or the adjustment screw (b screw is it?).
But it won’t make much difference tbh.

Big cogs = low hanging mech.

This is partly why I tend to run a SS in winter, that and less grinding away of expensive gear parts.

Yes, a very good point on the SS – great excuse for a new build or bring the CX out of semi retirement!

Chain is as short as I’m comfortable with a b-screw is pretty sensitive to adjustment on this setup so no movement there, but as you say probably wouldn’t make a lot of difference.

Will put up with it and try to avoid the really muddy stuff!

You are stuck with it, SRAM or Shimano. As said above, it needs to be long enough to work with those gears. I reckon its only an issue when riding through very deep mud, as you just did. I ride all year round and not had an issue. If the slop is that deep I try another route 🙂

About half way into a horrible section I had the same thought about route choice but it was too late by the – too many horses actually using bridalways near me it seems!

Are you running a long cage mech?

Unless you’re running a 2x set up with massive range a short cage will be just fine.

It’s an M8100 SGS – the 1x version. It only comes in 1 version as far as I’m aware, but definitely the 1x variant and not the M8120 which is 2×12

And cassette is 10-50 with 32t front chainring

As others say, that’s the way it is with 1×12, reality is that the mud is the least of your worries, mine tends to clog up a lot, but still workable with the down then up shift to get in the right gear.

The issue for me is mine is a couple of months old and looks like it’s been hit with a hammer over and over, going through ruts, rocks, etc is taking its toll more than mud, can’t see this mech lasting a year!

Big cogs = low hanging mech.

This. 20 years ago, a 34 tooth sprocket was for weaklings, real men ran 11-28. These days, 42 teeth is considered hard man stuff and 50 teeth is normal.

Does anyone know the clearance difference between 8120 vs 8100, I hardly use the 51t so I’m considering buying a 8120

They are very exposed to hits.
While on holiday in the Lakes this summer my Sram NX shifter packed up. I was wanting to upgrade anyway so bought a new SLX shifter and XT mech. After fitting them I went for a ride (Borrowdale Bash) and this happened.

Yep, that’s 1 hr old!

Ouch that sucks – luckily rocks aren’t too much of an issue for me at the moment, just deep, gloopy, mud!

Was your old sram set up any different in clearance or just unlucky with a rock?

This. 20 years ago, a 34 tooth sprocket was for weaklings, real men ran 11-28. These days, 42 teeth is considered hard man stuff and 50 teeth is normal.

With a 22T on 26″ wheels…

Now we’re on 32T fronts and 29″ wheels.

11-46 with a mid cage derailleur is a really practical option. Low profile fairly light, robust, cost effective and enough range for most. Run a 30t up front if really hilly 32t if not. Just because 50t plus cassettes are out there doesn’t make them the best option for every mountain biker. As above if the 51t is rarely used a big heavy expensive cassette and vulnerable low slung mech is a liability to be dragged around. The bike mag reviews don’t cut much slack for gearing that isn’t close to the widest range possible. I ride in the Pennines and Lakes trail centres on 2 hour runs and almost never use the 46.

Good call, thanks. Will look into that – the second hand market is fairly buoyant at the moment so I should be able to move on the 2 x sram GX 10-50’s that I have!! (Went sram cassette as well have XD drivers on my wheels and like the interface).

Guessing the mid cage is the 8120 model then?

Just found a pic of my bike with 1×11 – night and day in terms of clearance – oops!