Modified Stock Gearing - Boston Gear

Roller Chain Drives
Selection
SPEED RATIOS - CENTER DISTANCES - CHAIN LENGTHS
H
Teeth
Driven
Teeth on Driver Sprocket
Sprocket 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
4.36 4.00 3.69 3.43 3.20 3.00 2.92 2.67 2.52 2.40 2.28 2.18 2.08 2.00 1.92
48 18.294 18.085 18.925 18.713 18.500 18.287 19.110 18.894 18.677 19.489 19.270 20.073 18.829 19.628 20.422
68 68 70 70 70 70 72 72 72 74 74 76 74 76 78
4.91 4.50 4.15 3.86 3.60 3.38 3.18 3.00 2.84 2.70 2.57 2.46 2.34 2.25 2.16
54 19.539 20.396 20.186 19.977 20.819 20.607 20.395 21.223 21.008 21.827 21.609 21.392 22.200 21.980 21.760
74 76 76 76 78 78 78 80 80 82 82 82 84 84 84
5.45 5.00 4.61 4.29 4.00 3.75 3.53 3.33 3.16 3.00 2.86 2.73 2.61 2.50 2.40
60 21.843 21.637 22.496 22.287 22.079 22.923 22.712 22.501 23.332 23.119 23.492 23.726 23.510 24.323 24.104
82 82 84 84 84 86 86 86 88 88 90 90 90 92 92
5.83 5.39 5.00 4.67 4.37 4.12 3.89 3.68 3.50 3.33 3.18 3.04 2.92 2.80
70 25.834 25.628 25.422 26.279 26.071 25.863 26.708 26.498 26.287 27.121 26.910 26.695 27.522 27.306
96 96 96 98 98 98 100 100 100 102 102 102 104 104
6.00 5.54 5.14 4.80 4.50 4.24 4.00 3.79 3.60 3.43 3.27 3.13 3.00 2.88
72 26.244 26.038 25.834 26.694 26.487 27.337 27.128 27.918 27.758 27.547 27.334 28.164 27.951 27.736
98 98 98 100 100 102 102 102 104 104 104 106 106 106
5.71 5.33 5.00 4.70 4.44 4.21 4.00 3.81 3.64 3.48 3.33 3.20
80 28.545 29.413 29.206 29.000 29.855 29.647 31.330 30.283 30.073 30.910 30.699 30.486
108 110 110 110 112 112 118 114 114 116 118 116
6.00 5.60 5.25 4.94 4.66 4.41 4.20 4.00 3.82 3.65 3.50 3.36
84 30.439 30.234 31.098 30.891 30.685 31.539 31.330 31.122 31.965 31.755 31.544 32.380
114 114 116 116 116 118 118 118 120 120 120 122
6.00 5.64 5.33 5.05 4.80 4.57 4.36 4.17 4.00 3.84
96 34.633 34.429 35.295 35.088 34.882 35.738 35.531 35.322 36.170 35.960
130 130 132 132 132 134 134 134 136 136
5.90 5.60 5.33 5.03 4.87 4.67 4.48
112 40.516 40.312 41.177 40.971 40.765 41.622 41.414
152 152 154 154 154 156 156
264 Boston Gear 800-825-6544 P-1930-BG 04/10