Why reinvent the wheel when you can reinvent the chainring? The absoluteBLACK Race Face Direct Mount Boost Oval Chainring for Shimano HG+ 12 spd increases pedaling effectiveness by conserving energy through the weakest part of your stroke, and maximizing power transfer through the strongest. The result is a remarkably smooth pedal stroke that feels great during heavy climbs. It's science, and it works! Designed for use with Shimano 12spd Hyperglide+ Chains, this chainring will keep you going long after the homies have tapped out.