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Sram 11 speed rear derailleur in a 2x10 speed drivetrain?

by jurth
Fri, Jan 27, 2017 07:40
5

My allroad bike need a new rear derailleur, the current one is broken (SRAM x9). It uses a mixture of SRAM x9 and Apex drivetrain.
I thinking about changing to the whole goupset to a 1x hydraulic setup. However i´m not quite ready to shift to 1x and not sure I want to use the that kind money on whole new groupset.

So I got the idea to get a 11 speed ready derailleur and use it my current setup. That way, I can later upgrade to 1x a bit cheaper. SRAM have three options: Force 1, Rival 1 and Apex 1. According to SRAM: https://www.sram.com/sram/road/products/sram-apex-1-rear-derailleur the Apex 1 is compatible with 1x10 speed, however my setup would be 2x10.

I does not have to be a road derailleur, NX/GX/X0 would also be fine, however i´m not sure that would change anything compatibility wise.

So the question is, will this work?

Thanks in advance

/Jonas

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5 comments

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jurth | 7 years ago
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Hi everybody.

Thanks for all your answers.

Just to make it clear, I'm looking to use a SRAM 1x11 rear derailleur with a 10 speed shifter (Apex) and cassette. (Knowing it won't give me a 11 speed 1 )

I have done some research as well, and your answers helped to conclude that it won't work.

According to the SRAM website my current rear derailleur (x9) and their 1x11 rear derailleurs have the same pull ratio (1:1), so that is not a problem.
However their 1x rear derailleurs use X-HORIZON design, that does not work with double chainring. I found this explanation why: http://bicycles.stackexchange.com/questions/24507/can-double-chainrings-...

So I think I just need to get an x9 rear derailleur, or upgrade the whole group set 1

/Jonas

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VeloUSA | 7 years ago
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Using 9 speed shifter with 11 speed derailuer?  It will work, the shifter determines what cassette it will be compatible with, not the derailluer. As DaSy mentioned, the shifter cable pull determines how far the derailluer travels across each rear cog. Therefore, you cannot use a 9 speed cassette with 11 speed shifters, and visa versa - 11 speed cassette with 9 speed shifters.

Addendum: I should note, I used 9 speed as an example not 10, but the same issues of cable pull still applies. The shifts will not line up across the entire cassette range, because an 11-speed cassette is not just a 10-speed cassette with an extra cog stuck on at the same spacing. Rather, the spacing between 11-speed cogs is narrower than between 10-speed ones. I apologize for the confusion.

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DaSy | 7 years ago
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The pull ratio of your X9 derailleur (1.1) is different to the Apex 1 mech you link to (the road 10 and 11 SRAM pull ratio is 1.3).

Also the cable pull required at the shifter is 4mm on X9, so assuming that all is indexing correctly at present, I would assume the shifter you have is pulling 4mm per click. The Apex 1 requires 3.1mm pull per click. 

You would therefore get 5.2mm of sideway movement at the derailleur with a 1:1 compatible shifter mated to a Apex 1 (10/11 SRAM road compatible) mech, but need 4.4mm to index correctly on a SRAM 9 speed cassette.

 

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TypeVertigo | 7 years ago
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The 1x SRAM rear derailleurs are not meant to work with multiple chainrings, as far as I'm aware. The parallelogram design is such that it is no longer slanted, but straight in its travel. They call this their "X-HORIZON" design.

If I were you, I'd just get a regular SRAM 10-speed rear derailleur.

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CXR94Di2 | 7 years ago
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1x10. Will work with a 2x10 setup. Especially if the rear derailleur is long cage or MTB version, to take up chain slack

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