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Measuring Circumference
If your wheel size is not listed on the Memory-Map Bike 270 Pro for selection, you can go to
User Define
to
manually enter your circumference.
To measure your circumference, choose Method A or B and follow the steps described and illustrated below.
Or you can consult your bike dealer for information of the bike circumference.
Method A:
You can calculate the circumference of your bike by simple math as following formula.
Step 1.
Measure the diameter. The diameter of the wheel (wheel height) is the distance across a circle
through its center.
Step 2.
Calculate the circumference. Multiply the diameter of the wheel height
by pi. If the diameter of the wheel (wheel height) is 500 millimeters
across, then circumference would be 500 times 3.14 or 1570
millimeters.
Note: Please
use the metric system for entering the circumference value.
Convert the value if the measurement is in imperial system. For
example, when the diameter of the wheel is 20 inches, the
circumference would be 20 times 25.4 times 3.14 or 1595.12 millimeters.
Method B:
Step 1. M
ark the front tire at a point aligned with the inner tube’s valve stem.
Step 2. On a flat surface, use a chalk and draw a straight line.
Step 3 Rotate the front wheel so that the valve stem is directly on top of the point where the line begins.
Step 4 Wheel your bicycle on the line for one wheel revolution. Use the valve stem position stem to
determine when one revolution is completed.
Step 5 Mark the second point and measure. Mark the point on the line that corresponds to one revolution
of the wheel. Measure the distance between the two marks you created. This distance is the
circumference of your bicycle wheel.