Any Shimano, or Shimano-compatible 9 speed shifter will work. Just not SRAM 1:1
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wgscott I put NX 11 speed on my wife's bike and she is pleased with no more front shifting but really misses her EZ-fire shifter. I'm considering swapping it for the SLX 11-speed set I have on the tandem, or trying an XT shifter. The conversion was more expensive than I expected because she had one of the cranksets with riveted rings.