1x vs 2x Shimano 12 speed Derailleurs, SLX, XT and XTR, M8100 vs M7120

1x vs 2x 12 speed #Shimano #derailleur - SLX, XT and XTR #12speed options explained. What works with 10-51T and 10-45T cassettes, design differences, applications, and recommendations.

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[jamesturner]

I just got 1 x 12 XT installed today and took for ride and love it. Gotta get use to shifting under power! Even though I can with this new drive train. I’m use to it. After not shifting under power for so many years

[reedmelicher]

My next bike will almost certainly be 2x12. I constantly use my front derailleur to pedal over rolling hills. Maybe if double shifting is as effortless as they claim I'll change my mind

[ttomasmiranda]

i got a 2x12 XT here! (M8120 sgs, 38-28 cranks) installed few days ago, just two rides by now. feels awesome

[beauharvey]

Can you use a slx m7120 derailleur with old 11-46t 11 speed cassettes. Thanks.

[DoctorFunk]

I have mistakenly bought 2x12 derailleur and a 10-51 tooth cassette. Do you think it will work, do you have any experiences?

[francisbeladas]

Please do a video with a m7120 or m8120 rd on a 50 or 51t cassette.

[黄辰旭]

M8000 long cage can use 46 t cassette, M7120 has a even longer cage, I think it can take on 51 t cassette well. well, I don't have 12s freehub wheel right now.
The shimano manual always lists the most caution Specifications & Compatibility for thei products, especially the 'TOTAL CAPACITY'.
M8000 has 47 t capacity, and for X120 and X100 it only has 45 and 41. LOL

It's a really useful difference comparsion. And this video compares the 11 speed SGS RD and 12 s SGS/GS RD (but not mentioned on video description), really good, deep and detail. And 3:06, the description mislip is M810 (missed the second '0') on the vdieo.

[JogBird]

Got a 2020 trek top fuel recently w xt 12 spd, its not a special sku, but, the store only stocked the gx version.. Ill take xt over gx any day

[KibAgong]

Can I use the m8120 on my 1x with 51tcassette?

[joelrunyan]

Your video inspired me to experiment.. what I found? Is that the cheap 5100 11 speed derailleur for 11 51... works perfect as a 12 speed derailleur.. just pair it with a 12 speed shifter.. I did however swap over the pulley gears from a broken 8100 derailleur.. but don't know if I actually needed to

[basengelblik]

Great info, but I am lost. Still had to research the data sheets.

[andrewc.]

Hi, can you also use m8120 rd on a 10-51t cassette?

[imranvp]

Hi, I've ordered a Giant XTC 820. It comes with a SLX 2x drivetrain. These are the specs:

Crank: CLAIV 28-38
Front Derailleur:Shimano SLX FD M7100 22S
Rear Derailleur:Shimano SLX RD M7120 12 s
Freewheel: Shimano SLX (10-45T)

My question is: Can I change the shifter to an XT one as it's superior to the SLX isn't it? Will it still be compatible?

[paolodeang]

Can i use M8120 on a 1x12 / 10-45? Thankyou

[paolopaz]

Hello can i use m8120 sgs long cage on 50t cogs and 34t chain ring? Thanks 😊

[jumpoverthelazydog]

I bought the 8120rd . Will it be okay to run itnwith the 10-51t cog? What will be the issues ?

[hardwarito]

Great video! A question, slx and XT are compatible for 11 speed? Greetings from Chile!

[shafhamid]

I currently have a 2x10 on a 2016 Scott Genius. Once parts for my 10 speed become harder to get I plan to upgrade to a 2x12 setup. I would still like to be using a 2x setup because why not since my bike can fit a FD. Concerns I have are:
1. Does Shimano Micro Spline work well on a 142mm rear hub because that is the width of my rear dropout. Would it be friendly to a 2x setup for that matter?
2. My current chainring setup is a 22/36T for my 10 speed, works fine. Can I use the same FD, cranks & chainring on the 12 speed?
3. If I cannot for point number 2, could I use the 24/34T setup from the 11 speed series for a 2x12 setup?

For point 2 & 3, reason I ask is because current Shimano 2x12 cranksets are either 26/36T or 28/38T. They don't make 24/34T cranksets for 12speed which is what I'm looking to give me the most optimal gearing range. With a 24/34T & 10-45T setup I can best any 1x12 setup out there in terms of gear ratios. Most 1x cranksets out there are 30, 32 or 34T. A 24/34T 2x setup will be better than any 1x setup in both the lowest and highest gear ratio. My smallest gear ratio would be = 24/45 = 0.53333 and my highest = 34/10 = 3.4.

Because of the better range from a 2x12 setup, it is crucial for me to know whether I can still use my current 22/36T meant for 10 speed or could I use the 24/34T from the 11 speed series at least? If not are there third party 24/34T cranksets that are Shimano 12 speed compatible?

[jonienglish]

Question ?
SLX Rear Mech Jocky Pulleys are they Ball Bearing ? or Bushing

[steezmedia]

Hello, running 1x with a 45t cassette. Will the 2x mech work ok with it? Bought one as a spare