CatEye Q3A - Manual (Page 18)

ENG-17
Before use
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Tire circumference
You can find the tire circumference (L) of your tire size in the tire circum-
ference reference table below, or actually measure the tire circumference
(L) of your bicycle.
How to measure the tire circumference (L)
For the most accurate measurement, do a wheel roll out. With the tires under
proper pressure, place the valve stem at the bottom. Mark the spot on the floor and with the rider's weight
on the bike, roll exactly one wheel revolution in a straight line (until the valve comes around again to the
bottom). Mark where the valve stem is and measure the distance on the ground in millimeters.
For your reference, use the tire circumference table below. *
Tire circumference reference table
L mm
ETRTO Tire size
L
(mm)
47-203 12 x 1.75 935
54-203 12 x 1.95 940
40-254 14 x 1.50 1020
47-254 14 x 1.75 1055
40-305 16 x 1.50 1185
47-305 16 x 1.75 1195
54-305 16 x 2.00 1245
28-349 16 x 1-1/8 1290
37-349 16 x 1-3/8 1300
32-369
17 x
1-1/4(369)
1340
40-355 18 x 1.50 1340
47-355 18 x 1.75 1350
32-406 20 x 1.25 1450
35-406 20 x 1.35 1460
40-406 20 x 1.50 1490
47-406 20 x 1.75 1515
50-406 20 x 1.95 1565
28-451 20 x 1-1/8 1545
37-451 20 x 1-3/8 1615
37-501 22 x 1-3/8 1770
40-501 22 x 1-1/2 1785
47-507 24 x 1.75
1890
50-507 24 x 2.00 1925
54-507 24 x 2.125 1965
25-520 24 x 1(520) 1753
24 x 3/4
Tubular
1785
28-540 24 x 1-1/8 1795
32-540 24 x 1-1/4 1905
25-559 26 x 1(559) 1913
ETRTO Tire size
L
(mm)
32-559 26 x 1.25 1950
37-559 26 x 1.40 2005
40-559 26 x 1.50 2010
47-559 26 x 1.75 2023
50-559 26 x 1.95 2050
54-559 26 x 2.10 2068
57-559 26 x 2.125 2070
58-559 26 x 2.35
2083
75-559 26 x 3.00 2170
28-590 26 x 1-1/8 1970
37-590 26 x 1-3/8 2068
37-584 26 x 1-1/2 2100
650C
Tubular
26 x 7/8
1920
20-571 650 x 20C 1938
23-571 650 x 23C 1944
25-571
650 x 25C
26 x 1(571)
1952
40-590 650 x 38A 2125
40-584 650 x 38B 2105
25-630 27 x 1(630) 2145
28-630 27 x 1-1/8 2155
32-630 27 x 1-1/4 2161
37-630 27 x 1-3/8 2169
18-622 700 x 18C 2070
19-622 700 x 19C 2080
20-622 700 x 20C 2086
23-622 700 x 23C 2096
25-622 700 x 25C 2105
28-622 700 x 28C 2136
ETRTO Tire size
L
(mm)
30-622 700 x 30C 2146
32-622 700 x 32C 2155
700C
Tubular
2130
35-622 700 x 35C 2168
38-622 700 x 38C 2180
40-622 700 x 40C 2200
42-622 700 x 42C 2224
44-622 700 x 44C 2235
45-622 700 x 45C 2242
47-622 700 x 47C 2268
54-622 29 x 2.1
2288
60-622 29 x 2.3 2326