Motorcycle Tire Size Converter

Motorcycle tire sizes follow different formats. Metric format (120/70-17) shows width in mm, aspect ratio as percentage, and rim diameter in inches. Imperial format (3.25-19) shows width and rim diameter in inches. Alphanumeric codes (MT90-16) use letters and numbers to represent dimensions.

The aspect ratio is the sidewall height expressed as a percentage of the tire width. For example, in 120/70-17, the sidewall height is 70% of 120mm width, which equals 84mm sidewall height.

Yes, you can use equivalent sizes in different formats as long as the overall diameter remains close to the original. Use a converter to ensure compatibility and maintain proper speedometer accuracy and handling characteristics.

Metric sizing uses millimeters for width and includes aspect ratio (120/70-17), while imperial sizing uses inches for both width and rim diameter (3.25-19). Imperial sizes don't specify aspect ratio, which is typically around 100%.

Alphanumeric codes use letters to indicate tire width (M = medium range) followed by load rating and speed rating. For example, MT90 indicates a specific width range with a 90 load rating. These are commonly used on cruiser and touring motorcycles.

Overall diameter affects speedometer accuracy, ground clearance, and handling characteristics. When changing tire sizes, try to keep the overall diameter within ±3% of the original to maintain proper motorcycle performance and safety.

Using incorrect tire sizes can affect speedometer accuracy, handling, ground clearance, and safety. Larger diameter tires may rub against fenders or swing arms, while smaller ones can alter the motorcycle's geometry and performance characteristics.