The materials, technology and performance have been designed with racing in mind. The lightness of Chorus is provided by aluminum and composite materials. The 11-speed Chorus crankset has been embelished by the new surface anodization treatment which renders the chainrings more resistant to wear and to corrosion. The asymmetrical toothing of the innermost chainring and the eight pins on the outside render shifting immediate. 11 Speed compatible only. 688 grams (172.5mm, 53/39, weighed without bottom bracket cups).