Krawalde

Hi There,
I didn't find an answer for my particular question...If there is already an answer to this i am really sorry...but I need a quick solution for this problem.
I am in Chile on my way to Patagonia/Ushuaia with my Kona Sutra 2021 (26,38,48 T front and 11-36 T Rear). The rear derailleur is broken. It is a Shimano Deore T6000 (SGS, long cage). The only replacement I can get here is a Shimano XT MD8000 11x or a Shimano Deore RD M5120 for 1-2x10/11. I understand that both aren't ideal, but do you know if I can make one of those fit? I think I am able to do any adjustments if I have a little instructions.

Thank u very much in advance.

dedhed

Shimano compatibility chart.
Someone here should have a more helpful answer

​​​​​​https://productinfo.shimano.com/#/co...432&acid=C-436

Krawalde

[QUOTE=dedhed;22369145]Shimano compatibility chart.
Someone here should have a more helpful answeranswe QUOTE]
Thank u. I understand from this chart that the m5120 is not compatible. But does that mean that the M8000 for 11x is the better option? But I am not sure if I am understanding the chart correctly.....

Andrew R Stewart 

I assume the bike has no friction shifting option. Andy

Russ Roth

Looking at the chart, the Deore RD M5120 should work fine. All the 10sp shifters they list in the one box will shift any of the derailleurs that the box connects to, this includes both your old der and the m5120, where the break down is occurs in what the der will shift through, the old one that's broken would only shift through to a 32t or 36t, not clear why but seems to be single vs double rings while the 5120 will go a 42t or 46t based on single or double. So its more der than you need but probably cheaper than the XT and lets you make cassette upgrades later if you need.

TPL

You have elequently voiced a real world issue / concern as to why the simplest, most straightforward solution should be employed from the 'get go' = FRICTION SHIFTING !

Darth Lefty 

The 5120 is a larger derailleur made for 42-46 tooth bottom gears but less chain wrap capacity. So it will not sit as close to the cassette as the T6000. Shifting will be sloppier. You may have some slack in small-small combinations.

The M8000 might be better than M5120 or not, it is also larger than the T6000. But you want to make sure it’s the SGS version for 2x or 3x which has as much chain wrap as your T6000 did, and not the GS version for 1x which does not have enough wrap by far.

Andrew and TPL, why are you hung up on shifters?

Krawalde

​​​​​​Yes thats the same result I came to after some research. The advantage about friction mode as I understand is, that you have total control about how much cable you pull, so that you are able to do finer adjustments

@Andrew @ Russ TPL
In fact I do have bar end shifters which can be switched between indexed and friction mode.

​​​​​​So I guess considering the above the M8000 is the better option? (Hope its not too large)

dedhed

Friction takes any compatibility issues out of the equation beyond derailleur capacity. With friction shifting you theoretically don't even need a RD from the same manufacturer.

70sSanO

I thought the actuation ratio for mtb RD’s were different for 11 speed than 10 speed.

John

Edit Added: Since you have done research you probably know that there are thousands of experts that will tell you whether mtb 10/11 speed RD's are compatible. And Shimano is of no help indicating that the M5120/M4120 works for both, but not showing M8000 11 speed RD being backward compatible to 10 speed. So it is really going to be your call.

Personally, I'd forget about min low sprocket shifting quality and focus on your chain wrap and FD difference. Your 3x10 has a wrap is 47t and your FD difference is 22t. The M8000 is better suited for your setup. The M8000 RD min is 40t with a 47t wrap and an 18t FD.