There are three different units used to measure tires: Alpha, Inch/Standard, and Metric. Most manufacturers use metric measurements as their "default" units, but
NOT ALWAYS, so check your OEM tires first and don't hesitate to contact
Scooterworks if you have any questions about fitment. Below, you'll see a few examples of tire widths using the three different units.
| INCH/STANDARD | 3.00 | 3.25 | 3.50 | 4.00 | 4.50 | 5.00 | 5.50 | 6.00 |
| METRIC | 80 | 90 | 100 | 110 | 120 | 130 | 140 | 140 |
| ALPHA | MH | MJ | MM | MP | MR | MT | MU | MV |
Q: How do I know what size my tire is?A: Your tire size can be found molded into the sidewall on each of your tires. The print is often (but not always) the largest text on the tire, and is read as follows ...
Example A (Inch/Standard units): 3.5 x 10
in this example, 3.5 denotes the overall width of the tire in inches. 10 denotes the rim diameter.
Example B (Metric units): 100/90-10
in this example, 100 denotes the tire width in millimeters and 90 denotes the aspect ratio. The aspect ratio is the sidewall height of the tire described as a percentage of tire width, such that (in this example) 100/90 indicates a tire width of 100 mm, and a sidewall height equal to 90% of 100mm (or, 90mm). 10 denotes the rim diameter in inches.
Example C (Alpha units):
Alphanumeric measurement was originally introduced for OEM and manufacturer use, and will not normally be found on aftermarket tires (unless they are a direct, "factory-fresh" replacement). In most cases, the tire size will be printed on the sidewall in both Alpha and Metric units.
TIP 1: when ordering tires, use the Metric notation format whenever possible.
TIP 2: rim diameter is not measured at the lip, but where the bead of the tire meets the rim.
For more information about availability and sizing/color/performance options, check out
Scooterworks' Tire Page, or call Scooterworks at 1.888.96.VESPA.
 Prima 3.5 x 10" whitewall |