The Shimano Ultegra 6500 Hyperglide series 9-speed cassette offers reduced weight and increased rigidity. Steel chain rings with an aluminum carrier reduces weight and increases rigidity. Low chain ring 12, high chain ring 25; range 12, 13, 14, 15, 17, 19, 21, 23, 25. Reduced cog spacing: 9-speed cassette is same width as 8-speed. Fits 8-speed Shimano freehub bodies, must use 9-speed chain.