Not all stock components are a fit for individual riders, so Shimano offers the Ultegra FC-R8000 Chainring to help you customize your gearing after-market. The Ultegra features improved shifting and chain retention thanks to an updated tooth design-technology that makes it harder to drop your chain and easier to maintain your cadence. Aluminum construction uses Hollowglide technology to maximize stiffness while maintaining the light weight cyclists love.