Uite si raspunsul integral al celor de la Sram
[i]
The 10 speed rear derailleurs do not function with 11 speed shifters and cassettes. The 11 speed road products are only compatible with 11 speed road; 11 speed MTB with 11 speed MTB. Additionally, the 11 speed road and MTB systems do not work together. The 11 speed MTB shifters will not work with 11 speed road derailleurs, and vice versa.
The 10 speed road and MTB products will work together, however. You can use road shifters with MTB rear derailleurs and cassettes for 10 speed if they all are using the 10 speed platform[/i]