CB750 Drive Chain Tech Tip

Don’t overtighten your chain if you do you most likely end up with a hole in your crankcase. The slack shown in figure A should be 3/4 – 1 inch spin the rear wheel if it’s tight and then lose your chain and sprockets are worn. Replace the chain and sprockets at the same time. Don’t replace the chain and not do the sprockets.

Gearing:

CB750SOHC-Gearing-Chart-Skeeter

The above chart in Excel is handy to have.

 

 

Chain tightness

CB750K Gear Calculation
GEAR 1 2 3 4 5
Front Sprocket (Teeth) 17 17 17 17 17
Rear Sprocket (Teeth) 48 48 48 48 48
Tire Circumference (Inches) 83.567 83.567 83.567 83.567 83.567
Primary Drive 1.708 1.708 1.708 1.708 1.708
Secondary Drive 1.167 1.167 1.167 1.167 1.167
Final Drive 2.824 2.824 2.824 2.824 2.824
Internal Gear Ratio 2.500 1.708 1.333 1.097 0.939
Overall Gear Ratio 14.070 9.613 7.502 6.174 5.285
% Step to higher gear 32% 22% 18% 14%
GEAR 1 2 3 4 5
RPM MPH MPH MPH MPH MPH
1,000 6 8 11 13 15
1,500 8 12 16 19 22
2,000 11 16 21 26 30
2,500 14 21 26 32 37
3,000 17 25 32 38 45
3,500 20 29 37 45 52
4,000 22 33 42 51 60
4,500 25 37 47 58 67
5,000 28 41 53 64 75
5,500 31 45 58 70 82
6,000 34 49 63 77 90
6,500 37 54 69 83 97
7,000 39 58 74 90 105
7,500 42 62 79 96 112
8,000 45 66 84 103 120
8,500 48 70 90 109 127
9,000 51 74 95 115 135
9,500 53 78 100 122 142
10,000 56 82 105 128 150
10,500 59 86 111 135 157
11,000 62 91 116 141 165
11,500 65 95 121 147 172