Sprocket Gear Ratios

GEAR RATIOS FOR SPROCKETS

In theory increasing the number of teeth on the front sprocket and/or decreasing the number of teeth on the rear sprocket you will result in higher top speed, lower acceleration and better fuel economy. And vice versa: decreasing the number of teeth on the front sprocket and/or increasing the number of teeth on the rear sprocket will result in lower top speed, higher acceleration and worse fuel economy. However whilst generally true in practice this is not allways the case, mostly due to the power output of the machine at certain revs being higher or lower than at others. So use the following table as a guide only, to achieve your desired result will often involve some trial and error. It should also be noted that some models cannot accommodate larger front sprockets: check before ordering. Often the fitting of larger sprockets may require a longer chain: check before ordering.

R

e

a

r



S

p

r

o

c

k

e

t

Front Sprocket

10
11
12
13
14
15
16
17
18
19
30
3.00
2.73
2.50
2.31
2.14
2.00
1.88
1.76
1.67
1.58
31
3.10
2.82
2.58
2.38
2.21
2.07
1.94
1.82
1.72
1.63
32
3.20
2.91
2.67
2.46
2.29
2.13
2.00
1.88
1.78
1.68
33
3.30
3.00
2.75
2.54
2.36
2.20
2.06
1.94
1.83
1.74
34
3.40
3.09
2.83
2.62
2.43
2.27
2.13
2.00
1.89
1.79
35
3.50
3.18
2.92
2.69
2.50
2.33
2.19
2.06
1.94
1.84
36
3.60
3.27
3.00
2.77
2.57
2.40
2.25
2.12
2.00
1.89
37
3.70
3.36
3.08
2.85
2.64
2.47
2.31
2.18
2.06
1.95
38
3.80
3.45
3.17
2.92
2.71
2.53
2.38
2.24
2.11
2.00
39
3.90
3.55
3.25
3.00
2.79
2.60
2.44
2.29
2.17
2.05
40
4.00
3.64
3.33
3.08
2.86
2.67
2.50
2.35
2.22
2.11
41
4.10
3.73
3.42
3.15
2.93
2.73
2.56
2.41
2.28
2.16
42
4.20
3.82
3.50
3.23
3.00
2.80
2.63
2.47
2.33
2.21
43
4.30
3.91
3.58
3.31
3.07
2.87
2.69
2.53
2.39
2.26
44
4.40
4.00
3.67
3.38
3.14
2.93
2.75
2.59
2.44
2.32
45
4.50
4.09
3.75
3.46
3.21
3.00
2.81
2.65
2.50
2.37
46
4.60
4.18
3.83
3.54
3.29
3.07
2.88
2.71
2.56
2.42
47
4.70
4.27
3.92
3.62
3.36
3.13
2.94
2.76
2.61
2.47
48
4.80
4.36
4.00
3.69
3.43
3.20
3.00
2.82
2.67
2.53
49
4.90
4.45
4.08
3.77
3.50
3.27
3.06
2.88
2.72
2.58
50
5.00
4.55
4.17
3.85
3.57
3.33
3.13
2.94
2.78
2.63
51
6.10
4.64
4.25
3.92
3.64
3.40
3.19
3.00
2.83
2.68
52
6.20
4.73
4.33
4.00
3.71
3.47
3.25
3.06
2.89
2.74
53
6.30
4.82
4.42
4.08
3.79
3.53
3.31
3.12
2.94
2.79
54
6.40
4.91
4.50
4.15
3.86
3.60
3.38
3.18
3.00
2.84
55
6.50
5.00
4.58
4.23
3.93
3.67
3.44
3.24
3.06
2.89
56
6.60
5.09
4.67
4.31
4.00
3.73
3.50
3.29
3.11
2.95
57
6.70
5.18
4.75
4.38
4.07
3.80
3.56
3.35
3.17
3.00
58
6.80
5.27
4.83
4.46
4.14
3.87
3.63
3.41
3.22
3.05
59
6.90
5.36
4.92
4.54
4.21
3.93
3.69
3.47
3.28
3.11
60
7.00
5.45
5.00
4.62
4.29
4.00
3.75
3.53
3.33
3.16
61
7.10
5.55
5.08
4.69
4.36
4.07
3.81
3.59
3.39
3.21
62
7.20
5.64
5.17
4.77
4.43
4.13
3.88
3.65
3.44
3.26
Lowering the ratio increases top end speed - Increasing the ratio increases acceleration and bottom end power.