Determining tire circumference
Determine tire circumference (L) by referring to the tire size chart or by measuring the actual circumference of your bicycle tire.
- Tire circumference reference table - * The tire size or ETRTO code is indicated on the side of the tire.  
- Measure actual tire circumference - With tire air pressure adjusted appropriately, apply a load to the bicycle. - Using the valve, etc., as a marker, rotate the tire once and measure the distance traveled along the ground. - When using front wheel for speed measurement  - When using rear wheel for speed measurement  
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