The raw material for this fender comes with a 33cm radius (66cm diameter). Check your tire radius for the best possible fit with your specific tire. This fender is designed for use with 16" to 18" diameter tires. A special heat process is applied to each and every BK fender; after the welding process; to eliminate deformation and stress within the metal itself. Stress-free material will help avoid cracking or breaking when exposed to vibrations.All BK fenders are precision robotic plasma cut from extra (2.0mm) thick ''circle shape'' material which aids in strength and makes it easier to weld. Fenders are raw steel; without coating. Note: All fender widths given are approximate. Widths can vary slightly in the production process. Requires finish grinding.