What does the aspect ratio mean in tire sizing?
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.
Can I use different tire size formats on the same motorcycle?
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.
What's the difference between metric and imperial tire sizing?
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%.
How do alphanumeric tire codes work?
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.
Why is overall tire diameter important?
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.