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21
GEARING CHART
Minimum Combined Tooth Sum 107T (64DP)
Maximum Combined Tooth Sum 134T (64DP)
= 71.1mm/rev
43 (tyre dia) x
�
(3.142)
1.9 (gear ratio)
19
72
Spur
Pinion
76
78
88
94
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
97.78
92.64
90.26
95.97
90.92
88.59
94.16
89.20
86.92
92.35
87.49
85.25
90.54
85.77
83.57
88.73
84.06
81.90
86.92
82.34
80.23
85.11
80.63
78.56
83.30
78.91
76.89
68.15
81.49
77.20
75.22
66.67
79.67
75.48
73.55
65.19
77.86
73.77
71.87
63.71
76.05
72.05
70.20
62.23
74.24
70.33
68.53
60.74
72.43
68.62
66.86
59.26
55.48
70.62
66.90
65.19
57.78
54.09
68.81
65.19
63.52
56.30
52.71
67.00
63.47
61.85
54.82
51.32
65.19
61.76
60.17
53.34
49.93
63.38
60.04
58.50
51.85
48.54
58.33
56.83
50.37
47.16
56.61
55.16
48.89
45.77
54.90
53.49
47.41
44.38
53.18
51.82
45.93
43.00
50.14
44.45
41.61
48.47
42.96
40.22
41.48
38.84
40.00
37.45
38.52
36.06
37.04
34.67
35.56
33.29
34.08
31.90
32.59
30.51
31.11
29.13
29.63
27.74
28.15
26.35
In this chart we have given the mm/rev figures for
our suggested tyre size of 41.5mm, for a range of
spurs and pinions. If you prefer to use a different
size tyre, or to calculate as they wear, complete the
calculations below.
We suggest the use of 64DP spur and pinion gears
in this kit, in order to have maximum efficiency and
durability.
First work out the gear ratio from the spur gear and
pinion. (For example 76/40 = 1.9).
Then complete the following equation:
The Maximum and Minimum Combined tooth sum is
found by adding the pinion and spur sizes together.
This will show you quickly tell you if the pinion and
spur combination you would like to run will fit the car.
All of the rollout options shown in the chart will fit the
car.