Front sprockets are manufactured from heat-treated chromoly steel, are CNC-machined to extremely high tolerances, and have a yellow zinc finish to avoid corrosion. Rear sprockets are black anodized and are made from 7075-T6 billet aluminum (1/3 the weight of steel). They are CNC-machined for maximum fit accuracy and long-lasting durability.
Track/Race application: aluminum sprockets and 520 Series conversions are best suited for track or racing applications but can also be used for street use if the stock number of sprocket teeth is used. For a 520 Series conversion on an R1, gearing selection will vary from one track to another, but a good starting point would be a 15T front and 45T rear. To change gearing based on your particular track, a 16T front with 44T and 46T rears would provide a wide range of gearing selection.