Definition: Rolling resistance is the force required to initiate and maintain motion of a loaded caster across a surface.
What it affects: Push force, operator fatigue, energy consumption, and overall system efficiency.
Why rolling resistance matters
Rolling resistance directly determines how difficult equipment is to move. High resistance increases strain on operators and powered systems.
- Increases push and pull force requirements
- Accelerates operator fatigue and injury risk
- Reduces battery life in powered carts and AGVs
- Causes poor tracking and control
Reality: Most “hard to push” complaints are rolling resistance problems, not load capacity issues.
Primary factors that affect rolling resistance
- Wheel material: Harder materials generally roll easier on smooth floors.
- Wheel diameter: Larger diameters reduce resistance over seams and debris.
- Load: Higher loads increase contact deformation and resistance.
- Floor condition: Rough, soft, or dirty floors increase resistance.
- Bearing type: Precision bearings reduce internal friction.
Material and diameter comparisons
| Configuration | Rolling resistance trend |
|---|---|
| Large diameter, hard wheel | Lowest resistance on smooth floors |
| Small diameter, soft wheel | Highest resistance |
| Polyurethane vs rubber | Polyurethane typically rolls easier |
| Nylon on smooth concrete | Very low resistance, higher noise |
Always evaluate resistance under real load and floor conditions.
Common engineering mistakes
- Choosing wheel material based only on load rating
- Using small wheels on rough floors
- Ignoring bearing quality
- Underestimating operator push force limits
Rule: If equipment is difficult to move, increase wheel diameter before increasing load rating.
FAQs
Does higher load always mean higher rolling resistance?
Yes. Increased load increases wheel deformation and resistance.
What reduces rolling resistance the most?
Larger wheel diameter combined with a harder wheel material.
Are bearings important for rolling resistance?
Yes. Poor bearings add internal friction and increase push force.
Can rolling resistance be calculated?
It can be estimated, but real-world testing is recommended.