Most economical for your existing 11sp setup would be an 11-51 deore cassette.

Or you can get new 12 sp shifter, derailleur, cassette, chain and chainring if you want to go that way an get a 10-5x range instead.

 

Thanks, you both have suggested the same, so cleary it's the correct way forward, i'm just struggling to totally get the difference between what I have and what is being suggested

 

Deore 11 speed derailleur, Deore 11-51 cassette, and new chain will get you there economically. If you jump to 12 speed you'll need a Microspline driver also. Keep the 34T and upgrade the chain to Shimano as well. Use the savings on wheels for the biggest bang.

 

Excuse my ignorance, what's the difference between an SLX and Deore 11spd mech? I thought the only difference was weight, of which mine is marginally lighter? What will swapping to Deore do?

Having just put a new chain on, i'm interested to understand the difference between a KMC and Shimano chain? I thought they were universal, so as long as the KMC is 11spd there is no difference.

I'm clearly clueless!!!

I'm glad you mentioned wheels, that's the other thing i'm weighing up, I have my eye on SILT 29er XC Alloy rims which are a manageable cost for me but reviews are very light on the ground so i'm finding it hard to justify as i'm not sure they will make a huge difference?

If i'm buying new rims, is that the time to specify a microspline driver? Or am I best forgetting the 12spd route? I wasn't sure if my shifters, or mech were 12spd compatible?

 

If you have SLX 11 speed already, go for a Deore 11-51 cassette. Its identical to a 12 speed cassette except for the 3 smallest cogs.
You get to keep this stuff you have already:

• SLX 11 speed shifter
• HG freehub
• chainring

you will need to buy:

• CS-M5100 cassette
• RD-M5100 rear derailleur
• new 11 speed chain - maybe get 126 links instead of 116 if you have longer chainstays.

enjoy!

 

I have two of the 11 speed Deore 11-51 cassettes. These fit on a Hyperglide (as opposed to Microspline) freehub body. Not sure SLX offers the same configuration (wide range, 11 spd, Hyperglide.)

Microspline is specifically for 12 speed drivetrains. Hyperglide fits any number of cassettes 11 speed or less.

If you decide to go twelve speed (and you want to stick with Shimano), you’ll have to buy (at least) a new Microspline freehub body for your current hub and Microspline drivers are not offered as an upgrade for all hubs on the market. Might be available for yours, might not. If a Microspline driver isn’t offered for your current hub and you still want to go 12, then you’ll have to buy a new hub or new wheel. If you buy a new hub, then you’ll have to either build the new hub into a wheel using your old rim (don’t re-use spokes or nipples) or just buy a whole new wheel with a Microspline hub and toss your old wheel.

At some point you may find it’s both cheaper and easier to just buy a new pre-built 12 speed compatible wheel.

As someone who has both Shimano 11 speed and 12 speed bikes, personally I’d stick with 11. IMO the ONLY reason I’d go to 12 is to get the ten tooth small cog to gain more range. And you can accomplish a similar benefit by going with the 11 speed wide range 11-51 cassette. Not quite the same range but for many/most, enough.

I use KMC & SRAM chains with my Shimano 11 speed drivetrains. No complaints. Personally use a 12 speed chain with mine — I think it makes shifting slightly less finicky. I haven’t discovered a downside.
=sParty

 

My bike is a few years old now, and has served me very well. For an aluminium frame it's surprisingly light, actually lighter than a trek 9,6 Super calibre. My geo is really stretched out so i'm keen to keep my bike but would like to bring it up to speed, so to speak.

One of the upgrades (next 2-3 months) will be a new wheel set, so if the current hub is a sticking point this could be moot. That being said, I don't want to waste money...

The type of riding I do is pretty fast, which means I spend a lot of time on the small cog so end up eating through chains and cassettes, which was the reason for the 34T upgrade, but then i'm stuck with a lack of range on really hilly routes. I assumed 12spd was the best way over this.

 

could I go for another slx rear mech like this:

Shimano SLX M7100 Rear Derailleur - 12 Speed | Merlin Cycles

Buy your Shimano SLX M7100 Rear Derailleur - 12 Speed at Merlin. Free worldwide delivery available on most items!

www.merlincycles.com

Along with this shifter:

Shimano SLX M7100 Right Hand Gear Lever - 12 Speed | Merlin Cycles

Buy your Shimano SLX M7100 Right Hand Gear Lever - 12 Speed at Merlin. Free worldwide delivery available on most items!

www.merlincycles.com

 

could I go for another slx rear mech like this:

You can mix / match the mech and shifter as long as they are equal speeds, so you could do the SLX mech with an XT shifter. (Benefits of the XT shifter mentioned previously)

 

There are 3 groupings of compatible parts relevant to your here.

- Shimano 1x12s is on its own for the most part. You need every part to be shimano 12s compatible (deore, slx, xt, xtr, doesnt matter the level as long as they are 12s). So if you want 12s, you need the whole kit, INCLUDING a new microspline rear hub. Merlin has the full SLX kit usually in stock but hubs are tricky to find (hope, dt are hub options too, not just shimano brand).

- Shimano "old" HG 11s, like your slx is a different category. This is compatible is almost every other 11s HG shimano. Deore 5100 1x11 is a notable exception. You can only have up to 11-46t with these parts. Also note anything that says link glide (LG instead of HG) is an entirely different system and not compatible.

- The 3rd grouping is that deore 5100 11s. This is basically a hybrid between 12s and the old 11s. You can buy the derailleur, and the 11-51 cassette, and use your existing shifters, chain, crank, etc. You MUST use the 5100 derailleur and cassette together though. (note the 5120 model rear der is old style 11s compatible only, so you need the 5100 model here).

(there are some aftermarket items that sometimes let you break these rules, but this is the official guaranteed function)

 

- The 3rd grouping is that deore 5100 11s. This is basically a hybrid between 12s and the old 11s. You can buy the derailleur, and the 11-51 cassette, and use your existing shifters, chain, crank, etc. You MUST use the 5100 derailleur and cassette together though. (note the 5120 model rear der is old style 11s compatible only, so you need the 5100 model here).

Just to reinforce what is said here, a 5100 derailleur is not the same as a 5120, despite what the numbering may suggest. The 5120 has a 46t max vs 51t max for 5100.

 

I will point out something that hasn't been mentioned.

So, assuming that since you're planning new wheels already and it looks like the ones you have your eyes on allow for a microspline freehub body as a choice at a moderate price (haven't seen many of these wheel options around, so it's good to see), then yeah, you can choose to go all-in on shimano 12spd.

Doing so limits you to shimano 12spd ONLY moving forward. There aren't really any good aftermarket 12spd cassettes. In the 12spd world, Shimano and SRAM are only sorta compatible. You can mix some parts, but not others. If you do get into mixing stuff, you really need to know what you're doing because they're just different enough from each other, you're likely to have a slight loss of function. and it can be really bad if you hack at it.

for shimano 12spd, you need to be REALLY selective about your chainring. the differences between shimano and sram 12spd are most pronounced with the chain and chainring. a shimano 12spd chain is different on the inside of the links where it interfaces with the chainring, to the point that it WILL NOT FIT on rings designed only around sram 12spd. Some aftermarket chainring companies make rings compatible with either (for example, I use a OneUp ring on my bike, which claims compatibility with both SRAM and Shimano 12spd), but some do not. Depending on which crank you have, and the interface to the chainring it uses, you might have a hard time finding a chainring compatible with Shimano 12spd. An 11spd XT uses Shimano's proprietary bcd, and that one might be tricky.

There is the SRAM Eagle quick link trick that might work. I used it for awhile when there were very few shimano 12spd rings available (and none in the size I wanted), but it made me a little uncomfortable regarding its long-term use given that the Shimano 12spd chain interfaces with the chainring a little differently than SRAM.

If you're building a brand new bike and choosing all the parts for it, then it's pretty easy to go to shimano 12spd. But if you've got an old bike, as you can see, you have a lot of considerations to keep in mind and it's entirely possible that an upgrade could be a cascade of upgrades meaning you're dumping quite a bit of money into the bike.

It's going to be a LOT more economical to stay 11spd and keep your HG freehub body. It'd probably also be a lot less of a hassle, if you insist on 12spd, to go to an xD freehub body and go SRAM for your drivetrain, since that option has been around longer, and you don't have the chain/chainring consideration to deal with.