In theory, increasing the number of teeth on the front sprocket and/or decreasing the number of teeth on the rear sprocket will result in you achieving a 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 always 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 results 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 this too before ordering.
| FRONT | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| R E A R |
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 | 3.85 | 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 | 5.10 | 4.64 | 4.25 | 3.92 | 3.64 | 3.40 | 3.19 | 3.00 | 2.83 | 2.68 | |
| 52 | 5.20 | 4.73 | 4.33 | 4.00 | 3.71 | 3.47 | 3.25 | 3.06 | 2.89 | 2.74 | |
| 53 | 5.30 | 4.82 | 4.42 | 4.08 | 3.79 | 3.53 | 3.31 | 3.12 | 2.94 | 2.79 | |
| 54 | 5.40 | 4.91 | 4.50 | 4.15 | 3.86 | 3.60 | 3.38 | 3.18 | 3.00 | 2.84 | |
| 55 | 5.50 | 5.00 | 4.58 | 4.23 | 3.93 | 3.67 | 3.44 | 3.24 | 3.06 | 2.89 | |
| 56 | 5.60 | 5.09 | 4.67 | 4.31 | 4.00 | 3.73 | 3.50 | 3.29 | 3.11 | 2.95 | |
| 57 | 5.70 | 5.18 | 4.75 | 4.38 | 4.07 | 3.80 | 3.56 | 3.35 | 3.17 | 3.00 | |
| 58 | 5.80 | 5.27 | 4.83 | 4.46 | 4.14 | 3.87 | 3.63 | 3.41 | 3.22 | 3.05 | |
| 59 | 5.90 | 5.36 | 4.92 | 4.54 | 4.21 | 3.93 | 3.69 | 3.47 | 3.28 | 3.11 | |
| 60 | 6.00 | 5.45 | 5.00 | 4.62 | 4.29 | 4.00 | 3.75 | 3.53 | 3.33 | 3.16 | |
| 61 | 6.10 | 5.55 | 5.08 | 4.69 | 4.36 | 4.07 | 3.81 | 3.59 | 3.39 | 3.21 | |
| 62 | 6.20 | 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.
EN