Rolling Resistance Coefficients: Check Whether the Parameter Has Length Units

Keep the parameter convention

Hamilton uses a rolling-resistance form F = fW/R in which f has the same length units as wheel radius R. This differs from a dimensionless F/W convention. Primary reference: rolling resistance parameter units.

The symbol alone does not identify the convention. Preserve the formula, units and contact conditions with a quoted value. Rolling resistance also differs from the sliding-friction coefficient used for a slipping contact.

A fictional unit check

Assume a hypothetical wheel load of 500 N, a radius of 50 mm and a length parameter f = 1 mm. The stated form gives 10 N. The corresponding dimensionless ratio F/W is 0.02. Substituting 1 as a dimensionless coefficient would instead imply 500 N and lose the radius relationship.

If radius becomes 100 mm while this fictional f and load remain unchanged, the form gives 5 N. Actual parameter behavior may depend on the wheel, floor, speed and load, so the one-input comparison is not a performance prediction. No vendor table value is reused here.

Separate travel-force inputs

Create columns for each wheel load, radius, parameter convention and assumed resistance. Retain swivel, start-up, slope and bearing contributions as separate questions where relevant. A straight-line rolling model does not automatically include them.

Ask for the intended wheel/floor evidence before comparing purchase offers or estimating travel effort. Keep the actual load distribution visible; total equipment weight divided equally by wheel count may be unjustified. This guide reviews units, without approving manual handling or a particular caster arrangement.

Customer Questions

Primary References

These references support the technical principles discussed in this guide. The worked examples and review questions are educational.

• Primary reference: rolling resistance parameter units