If you want to know about gearing for other circuits then either select the option from the Technical menu
or Click Here ....

Select the required options and then
move cursor over MPH, KPH or RATIO
to perform calculation
RPM
Engine Sprocket
MPH
Axle Sprocket
KPH
Tyre Circumference (cm)
RATIO

The table below provides details of the ratio of engine to axle sprocket.
For example, to achieve a ratio of 8:1 you could use :
Engine - 9 : Axle - 72 ; Engine - 10 : Axle - 80 ; Engine - 11 : Axle - 88

Engine
Axle
9
10
11
12
13
14
15
16
17
18
19
20
60
6.67
6.00
5.45
5.00
4.62
4.29
4.00
3.75
3.53
3.33
3.16
3.00
61
6.78
6.10
5.55
5.08
4.69
4.36
4.07
3.81
3.59
3.39
3.21
3.05
62
6.89
6.20
5.64
5.17
4.77
4.43
4.13
3.88
3.65
3.44
3.26
3.10
63
7.00
6.30
5.73
5.25
4.85
4.50
4.20
3.94
3.71
3.50
3.32
3.15
64
7.11
6.40
5.82
5.33
4.92
4.57
4.27
4.00
3.76
3.56
3.37
3.20
65
7.22
6.50
5.91
5.42
5.00
4.64
4.33
4.06
3.82
3.61
3.42
3.25
66
7.33
6.60
6.00
5.50
5.08
4.71
4.40
4.13
3.88
3.67
3.47
3.30
67
7.44
6.70
6.09
5.58
5.15
4.79
4.47
4.19
3.94
3.72
3.53
3.35
68
7.56
6.80
6.18
5.67
5.23
4.86
4.53
4.25
4.00
3.78
3.58
3.40
69
7.67
6.90
6.27
5.75
5.31
4.93
4.60
4.31
4.06
3.83
3.63
3.45
70
7.78
7.00
6.36
5.83
5.38
5.00
4.67
4.38
4.12
3.89
3.68
3.50
71
7.89
7.10
6.45
5.92
5.46
5.07
4.73
4.44
4.18
3.94
3.74
3.55
72
8.00
7.20
6.55
6.00
5.54
5.14
4.80
4.50
4.24
4.00
3.79
3.60
73
8.11
7.30
6.64
6.08
5.62
5.21
4.87
4.56
4.29
4.06
3.84
3.65
74
8.22
7.40
6.73
6.17
5.69
5.29
4.93
4.63
4.35
4.11
3.89
3.70
75
8.33
7.50
6.82
6.25
5.77
5.36
5.00
4.69
4.41
4.17
3.95
3.75
76
8.44
7.60
6.91
6.33
5.85
5.43
5.07
4.75
4.47
4.22
4.00
3.80
77
8.56
7.70
7.00
6.42
5.92
5.50
5.13
4.81
4.53
4.28
4.05
3.85
78
8.67
7.80
7.09
6.50
6.00
5.57
5.20
4.88
4.59
4.33
4.11
3.90
79
8.78
7.90
7.18
6.58
6.08
5.64
5.27
4.94
4.65
4.39
4.16
3.95
80
8.89
8.00
7.27
6.67
6.15
5.71
5.33
5.00
4.71
4.44
4.21
4.00
81
9.00
8.10
7.36
6.75
6.23
5.79
5.40
5.06
4.76
4.50
4.26
4.05
82
9.11
8.20
7.45
6.83
6.31
5.86
5.47
5.13
4.82
4.56
4.32
4.10
83
9.22
8.30
7.55
6.92
6.38
5.93
5.53
5.19
4.88
4.61
4.37
4.15
84
9.33
8.40
7.64
7.00
6.46
6.00
5.60
5.25
4.94
4.67
4.42
4.20
85
9.44
8.50
7.73
7.08
6.54
6.07
5.67
5.31
5.00
4.72
4.47
4.25
86
9.56
8.60
7.82
7.17
6.62
6.14
5.73
5.38
5.06
4.78
4.53
4.30
87
9.67
8.70
7.91
7.25
6.69
6.21
5.80
5.44
5.12
4.83
4.58
4.35
88
9.78
8.80
8.00
7.33
6.77
6.29
5.87
5.50
5.18
4.89
4.63
4.40
89
9.89
8.90
8.09
7.42
6.85
6.36
5.93
5.56
5.24
4.94
4.68
4.45
90
10.00
9.00
8.18
7.50
6.92
6.43
6.00
5.63
5.29
5.00
4.74
4.50
91
10.11
9.10
8.27
7.58
7.00
6.50
6.07
5.69
5.35
5.06
4.79
4.55
92
10.22
9.20
8.36
7.67
7.08
6.57
6.13
5.75
5.41
5.11
4.84
4.60
93
10.33
9.30
8.45
7.75
7.15
6.64
6.20
5.81
5.47
5.17
4.89
4.65
94
10.44
9.40
8.55
7.83
7.23
6.71
6.27
5.88
5.53
5.22
4.95
4.70
95
10.56
9.50
8.64
7.92
7.31
6.79
6.33
5.94
5.59
5.28
5.00
4.75