- Arm Material: aluminum
- Arm Length: 170 mm 175 mm
- Chainring Sizes: 30 – 36 t
- Bottom Bracket: not included
- BB Type: multiple available
Answering the demand for one-by mountain drivetrains, Shimano has engineered the XTR FC-M9000-1 one-by Race Crank Arms, as part of the new XTR 9000 groupset, to be a light and reliable crank for those who prefer simplicity. The XTR M9000 crank arms are designed with the same hollow-armed alloy technology that Shimano uses on its double chainring drivetrains. The slight difference is that that left arm is now hollow-bonded to further reduce weight, without compromising durability and stiffness. Without the bottom bracket, the cranks weigh 583 grams. Meanwhile, the right crank arm now sports a four-arm spider that, regardless of the one-by designation, is compatible with all XTR 9000-series single and double chainring setups. It should be noted that the narrower Q-factor, 158mm, while increasing pedaling efficiency, will not work with several full-suspension frame designs.