Vetta V100 User Manual page 21

WHEEL SIZE CALCULATION
The circumference of the wheel is measured and entered in
millimeters. Bike I and II wheel sizes are set independently, and
both default to 2074mm (700c x 20 or 26 x 2.0). The following
chart lists the circumference measurements for the most
common wheel sizes. To use this chart, find your tire size and
record the corresponding circumference measurement.
TIRE SIZE
700c x 38mm
700c x 35mm
700c x 32mm
700c x 30mm
700c x 28mm
700c x 25mm
700c x 23mm
700c x 20mm
700c Tubular
650c x 23mm
650c x 20mm
If your wheel size is not on the chart, or if you want a more
precise calibration, wheel circumference may be calculated as
follows:
Step 1: Measure the distance from the center of the front wheel axle
to the ground in millimeters. (1 inch = 25.4mm)
Step 2: Multiply this distance by 6.2832 (2 ) and enter the
result as the wheel size setting into the computer.
OR... Mark the tire and a spot on the floor. Roll the wheel forward
one complete revolution until the tire mark touches the floor
again and mark that spot. Measure the distance between the
marks on the floor in millimeters and enter the result into the
computer.
CIRC TIRE SIZE
27" x 1-1/4"
2180
2168 27" x 1-1/8"
2155 26" x 2.25"
2145 26" x 2.1"
2136 26" x 2.0"
2124 26" x 1.9"
2105 26" x 1.75"
2074 26" x 1.5"
2130 26" x 1.25"
1990 26" x 1.0"
1945 20" x 1-1/4"
CIRC
2161
2155
2115
2095
2074
2055
2035
1985
1953
1913
1618