Calculating Tire and Wheel Frequency
WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
For a vibration concern, use the vehicle speed to determine tire/wheel frequency and RPM. Calculate tire and wheel RPM and frequency by carrying out the following:
- Measure the diameter of the tire.
- Record the speed at which the vibration occurs.
- Obtain the corresponding tire and wheel RPM and frequency from the Tire Speed and Frequency Chart.
- If the vehicle speed is not listed, calculate the tire and wheel frequency as follows:
- Divide the vehicle speed at which the vibration occurs by 16 km/h (10 mph). Multiply that number by the 16 km/h (10 mph) tire RPM listed for that tire diameter in the chart. Then divide that number by 60.
- For example, if calculating the frequency based on vehicle speed in km/h for a 64 km/h vibration with 835 mm tires, divide 64 km/h by 16 km/h = 4. Multiply 4 by 105 RPM = 420. Divide 420 by 60 seconds = 7 Hz at 64 km/h.
- If calculating the frequency based on vehicle speed in mph for a 40 mph vibration with 33 inch tires, divide 40 mph by 10 mph = 4. Multiply 4 by 105 RPM = 420. Divide 420 by 60 seconds = 7 Hz at 40 mph.
- The calculated frequency of 7 Hz is the first order tire and wheel vibration; the second order tire and wheel vibration would be twice this number at 14 Hz; the third order tire and wheel vibration would be 21 Hz; and so on.
TIRE SPEED AND FREQUENCY SPECIFICATION
| Tire Diameter | Tire RPM/Hz | Tire RPM/Hz | Tire RPM/Hz | Tire RPM/Hz |
|---|---|---|---|---|
| mm (in) | @ 16 km/h (10 mph) | @ 80 km/h (50 mph) | @ 97 km/h (60 mph) | @ 113 km/h (70 mph) |
| 483 (19) | 182 | 910/15 | 1092/18 | 1274/21 |
| 508 (20) | 173 | 865/14 | 1038/17 | 1211/20 |
| 533 (21) | 165 | 825/14 | 990/16 | 1155/19 |
| 560 (22) | 158 | 790/13 | 948/16 | 1106/18 |
| 585 (23) | 151 | 755/13 | 906/15 | 1057/18 |
| 610 (24) | 145 | 725/12 | 870/14 | 1015/17 |
| 635 (25) | 139 | 695/12 | 834/14 | 973/16 |
| 660 (26) | 134 | 670/11 | 804/13 | 938/16 |
| 685 (27) | 129 | 645/11 | 774/13 | 903/15 |
| 710 (28) | 124 | 620/10 | 744/12 | 868/14 |
| 735 (29) | 119 | 595/10 | 714/12 | 833/14 |
| 760 (30) | 115 | 575/10 | 690/11 | 805/13 |
| 785 (31) | 111 | 555/9 | 666/11 | 777/13 |
| 810 (32) | 108 | 540/9 | 648/11 | 756/13 |
| 835 (33) | 105 | 525/9 | 630/10 | 735/12 |
| 864 (34) | 102 | 510/8 | 612/10 | 714/12 |