Among the the massive changes incorporated into Shimano's new XTR M9100 group are the redesigned XTR cranks and chainrings, which now use a direct-mount interface that makes chainring swaps easier than ever while at the same time decreasing weight. With the XTR SM-CRM95 12 Speed Direct Mount Chainring you no longer have to deal with fussy chainring bolts, as you'll get a perfect fit every time with the direct mount system. The tooth profile has also been updated, now bearing a close resemblance to the narrow-wide design that has proven effective in the mountain bike world. The teeth connect seamlessly with the XTR CN-M9100 chain, reducing the natural vibrations normally caused by the inner and outer chain plates rolling onto the chainring and providing better chain engagement, stronger retention, and smoother pedaling--even over bumpy terrain.