Round chainrings are standard because, well, they're standard, but they don't actually match the changing power output of your legs through a pedal stroke. Absolute Black's SRAM Oval Direct Mount Traction Chainring's oblong shape makes pedaling easier in hard spots and steadier in easy spots, so you can keep a constant and smooth cadence without having to deal with dead up-strokes and leg-crushing down-strokes. This makes it easier to nail down the highly efficient circular pedaling motion that's we're all after, and improves traction by eliminating the wheel slip that happens during hard down-strokes on loose terrain. If you're going to make a killer chainring, you might as well pull out all the stops, so Absolute Black also machined this aluminum-alloy beauty with a narrow-wide tooth profile and 3D design that improves chain retention, sheds mud, and reduces wear and noise. It also engineered the Oval to mount directly to almost all SRAM cranksets, so you can eliminate the extra weight of a spider, which will be a boon to your quads when you're hammering up steep dirt and across fast sections of rolling singletrack. Run the 0mm offset models with a short spindle BB30 cranks and the 6mm offset with the standard BB30 spindle. The easiest way to identify which spindle you have is by checking the width of the spacer between the chainring and the bottom bracket shell. the short spindle has a 9mm spacer while the long or standard spindle has a 15mm spacer.