01/10/2007
I created an excel spreadsheet to determine what the tach should be at for a given speed and gear.
You can change the gear ratios and even compare results for different sized tires.
Enjoy
Ian
| RPM vs Speed Calculator | |||||||||
| Instructions: Fill in gearing info, fill in tire width, profile, rim size for up to 3 tires, fill in speed in either MPH or KM/H. The rpm in each gear is calculated for you. | |||||||||
| Gearing Info | |||||||||
| 1st | 2.771 | ||||||||
| 2nd | 1.543 | ||||||||
| 3rd | 1 | ||||||||
| 4th | 0.694 | ||||||||
| (5th) | |||||||||
| (6th) | |||||||||
| Final | 3.77 | ||||||||
| Tire Info | Tire 1 | Tire 2 | Tire 3 | ||||||
| Width (mm) | 225 | 225 | 225 | ||||||
| Profile | 50 | 55 | 60 | ||||||
| Rim Size (in) | 16 | 16 | 16 | ||||||
| Tire Height (in) | 24.86 | 25.74 | 26.63 | ||||||
| Tire Circumference (in) | 78.05 | 80.84 | 83.62 | ||||||
| English | Metric | ||||||||
| Speed (mph) | 144 | Speed (km/h) | 232 | ||||||
| Tire 1 | Tire 2 | Tire 3 | Tire 1 | Tire 2 | Tire 3 | ||||
| RPM in 1st | 20352 | 19652 | 18998 | RPM in 1st | 20374 | 19673 | 19019 | ||
| RPM in 2nd | 11333 | 10943 | 10579 | RPM in 2nd | 11345 | 10955 | 10590 | ||
| RPM in 3rd | 7345 | 7092 | 6856 | RPM in 3rd | 7353 | 7100 | 6863 | ||
| RPM in 4th | 5097 | 4922 | 4758 | RPM in 4th | 5103 | 4927 | 4763 | ||
| RPM in 5th | 0 | 0 | 0 | RPM in 5th | 0 | 0 | 0 | ||
| RPM in 6th | 0 | 0 | 0 | RPM in 6th | 0 | 0 | 0 | ||
| Results assume a locked torque convertor or a non-slipping clutch | |||||||||