While some manufacturers are constantly chasing trends and new standards, Shimano's approach is typically more measured. In the case of the XTR M9000 1 1x Race Crankset, the advantage to this circumspect manner manifests as a virtually perfect one by racing drivetrain. It's important to stress the racing aspect, as the Race model is designed with a lighter body than the burly Trail version. It weighs a claimed 554g, which recommends it for XC events but maybe not for big drop enduro courses. The new XTR M9000 crank arms do not deviate enormously from Shimano's consistently proven formula of hollow armed alloy cranks, but there are notable enhancements. The left crank arm is now hollow bonded, a manufacturing process that saves weight over previous production methods without giving up strength. The right arm likewise boasts reduced weight while also playing host to a new four bolt spider that is compatible with all double or single chainring configurations that Shimano now makes for the new 9000 series cranks. The solitary chainring received enormous amounts of attention in the redesign, too. Like the crank arms, the ring is also hollow to save weight, but its rigidity has only increased over the previous generation thanks in part to revolutionary carbon reinforced, titanium alloy construction. The titanium teeth are also hollowed out to shave as many grams as possible, which is just one of the weight saving features that help it achieve such an impressively featherweight presence on the scale. Finally, the Race version of the M9000 crankset features a 158mm wide Q factor narrower than the 168mm Trail version which boosts pedaling efficiency for racers but makes it incompatible with certain dual suspension frame designs. Please double check with us that the Race cranks will fit on your frame before ordering.