SRAM 11 Speed 1x11 and SRAM 12 Speed 1x12 Cassette Range

Well, let’s see how this works out. I have been trying a few different setups on my Hard Tail and FS bike to figure out what works best for me and the riding that I do. I bought a NX 11 speed derailleur and shifter and checked out what information that I could find on cassette compatibility. Of course, the SRAM compatibility chart lists cassettes to 42t I found a lot of information that suggested that SRAM 11 speed MTB 1x derailleurs would work with cassettes up to 50T. So I bought a SunRace 11 x 46T and a 11x 50T cassette. I ride my hard tail around mostly and wanted a good spread with a decent Bailout and good top speed for the flats (good is subjective, what is good for me may not be for you).

I started with a 32T chainring and ended at a 38T chainring. The 11x46T cassette worked well with the chainrings from 32t to 38t. No hanger extension needed; B adjust per SRAM Installation guide. Then the acid test, I bumped up to a 11x50T and things… well they didn’t work out as well. What it really boiled down to was that the derailleur couldn’t deal with the extra chain needed with a 50T bailout. So, I added a 22mm hanger extension. Like most quick and dirty solutions, it worked but it didn’t work well. The extension took care of the extra chain, and you pay for that with poor high end shifting. A hanger extension moves the derailleur either down, back, or down and back so you make the geometry for the bailout but you end up with too much distance between the upper pilot wheel and the high gears, 11t, 13t, 15t.. So, it hangs up on the up shift or down shift and you end up having to over shift to get it to go down and still allow derailleur to shift up on its own since you can’t over shift for shifting from larger to smaller cogs since that is fix by the shifter and derailleur return spring.

I mentioned that I have a FS also. On it I have a SRAM Eagle 12 Speed. I started to look at the differences between the 11 speed and 12 speed. There only seems to be 2 differences (there may be three), the cage and the pilot wheel size. Since X-Actuation is 1 to 1 eleven speed or twelve speed is same – same the shifter gets an additional stop in the shift range and the distance between stops shorten. So, I made a longer cage out of 6065 Aluminum that matched the Eagle pilot wheel geometry and distance but without the additional offset that the eagle cage assembly has from cage axis to pilot wheel chain line. With the extra length it could handle the chain without an extension, and it actually shifted well, up and down with the 11-50T cassette. Although I haven’t tried it yet, I feel very confident that it will work with the 11-52T SunRace 11 speed cassette. What I did find among other things is that a 11-50T cassette with a 36T chainring at 17” (432mm) center to center chain stay length uses 116 links. So I have to get a 126 link chain if I only want to use one quick link since I will need 2 more links for a 52t cassette and a 38t chainring.

I am wondering what other people have tried and what worked or didn’t. If anyone would like some more detail send me a message.