Correction Factors For Other Tire Sizes

To calculate ground speeds for tractors equipped with rear tires other than 16.9-28(R650 mm), R1 tires, multiply the ground speeds shown for the 16.9-28 (R650 mm), R1 tires from above chart with correction factor.

Correction factor is calculated by: Rolling radius of new tire/Rolling radius of tire for which ground speed are known

Example: Correction factor for 14.9-28 (R622 mm) with respect to 16.9-29 (R650 mm)= 622/650

Example: Ground speed of 14.9- 28 (R622 mm) at B-2, 2400 engine RPM

5.93km/h)*(622/650)= 5.67km/h

NOTE: Speed and correction factor information is based on rolling circumference information which vary with tire manufacturer.