Off-Roading
Four Wheel Drive Concepts
Offroad Driving Techniques
Vehicle Recovery Techniques
Reference
Calculators
   Gear Ratios
   Metric Tyre Height
Calculators

Gear Ratios. A change in tyre size changes your overall gear ratio. This section contains calulators to calulate Effective Gear Ratio, Engine RPM at a Given Speed, Equivalent Ratios for New Tyres, Speedometer Correction (Tyre Swap Only) and Speedometer Correction (Tyre and Gear Swap) with your new tyres.
Metric Tyre Height. Knowing the mounted height of a tyre is important to working out overall gear ratios and engine rpms. This calculator presents a formula for calculating the height of a metric tyre.