PBI 520 Front Sprocket Conversion - 20T , Sprocket Teeth: 20, Sprocket Position: Front, Material: Steel, Color: Natural, Sprocket Size: 520 277X-20-520 Manufactured from 7075 T6-51 aluminum Stronger than steel sprockets in tensile, yield and shear strength Far lighter than steel for less unsprung weight Made from full thickness aluminum for maximum strength Available in a full range of tooth sizes