Loaded Radius Comparator

This comparator works by converting each tire's static loaded radius into a 2πr circumference and revs per kilometer, then ranking the tires. Static loaded radius is the distance from hub center to ground with the vehicle's weight on the tire.

1. Enter Tire A's published static loaded radius, for example 345 mm (13.58 in).
2. Enter Tire B's value, for example 360 mm (14.17 in).
3. Read the radius gap: +15 mm (+0.59 in), or +4.3%.
4. Read the axle height change under load: +15 mm.

The formula is Gap (%) = (Radius B − Radius A) ÷ Radius A × 100.

Worked example: a 320 mm loaded radius gives 2πr = 2,011 mm and 497.4 revs per km. A 330 mm loaded radius gives 2,073 mm and 482.3 revs per km.

The conversion table converts 10 loaded radius values (280 mm to 400 mm) into inches, 2πr circumference and revs per km. Use it to rank tires, not to predict odometer error.

The true rolling circumference sits between 2π × loaded radius and π × unloaded diameter. The note under the table repeats this limit.

The Loaded Radius Comparator is a tool that compares tire makers' published static loaded radius values. Static loaded radius is smaller than the unloaded radius, and the gap grows with lower pressure and softer sidewalls.

Loaded radius sets the vehicle's ride height at rest and the lever arm for traction and braking. Suspension engineers use it for roll-center and anti-squat geometry.

This comparator has 4 uses: ride-height prediction, traction math, model ranking and suspension geometry.

• Predict ride height: See the real height change under weight.
• Compute traction: Use loaded radius for wheel force.
• Rank models: Compare sidewall stiffness across brands.
• Set suspension geometry: Feed real radius into setup sheets.