How Wheel Diameter Impacts Castors: A Comprehensive Guide

When selecting castors for various applications, one of the key considerations is the wheel diameter. Wheel size plays a critical role in how the castor functions in terms of mobility, load capacity, floor protection, and more. Understanding how wheel diameter impacts castors can help you choose the right one for your needs.

In this blog, we’ll explore how wheel diameter affects castor performance, backed with examples to guide your decision-making process.

1. Mobility and Maneuverability

One of the most noticeable impacts of wheel diameter is on mobility. Larger wheels generally offer smoother movement, especially over uneven surfaces or obstacles like thresholds, cables, or cracks in the floor.

Example: In industrial settings where trolleys are used on uneven floors, a large-diameter castor (e.g., 150mm or more) would be ideal for ensuring smooth movement over rough surfaces. Conversely, for indoor office chairs or lightweight furniture on smooth floors, smaller castors with 50-75mm diameters provide adequate mobility.

2. Load Capacity

Wheel diameter is directly linked to the load-bearing capacity of a castor. Larger wheels can typically carry more weight compared to smaller ones because they distribute the load more evenly and are less prone to damage from pressure.

Example: A warehouse cart-trolley carrying heavy pallets may require castors with a 200mm wheel diameter to handle loads exceeding 500kg. On the other hand, a light-duty trolley in a retail store may only need a 75mm wheel diameter to support lighter loads of up to 100kg.

3. Floor Protection

Larger wheels tend to exert less pressure on the floor, reducing the chances of damage, such as scuffs or scratches. This is particularly important in environments like hospitals, offices, or retail spaces where floor preservation is essential.

Example: For hospital equipment that needs to be moved frequently, castors with a larger diameter (e.g., 125mm) are often used. These larger wheels roll smoothly over delicate floors, minimizing wear and tear. In contrast, smaller wheels, if used with heavy loads, can cause floor damage over time.

4. Ease of Pushing and Pulling

Larger diameter wheels require less effort to push or pull, especially when navigating obstacles or rough terrain. They reduce rolling resistance, making the load easier to move.

Example: In outdoor industrial settings, a utility cart fitted with 200mm diameter castors will be easier to push over rough concrete surfaces compared to smaller wheels. In contrast, for small office chairs or furniture, a smaller wheel diameter (50 mm-75 mm) is more appropriate because the load is lighter, and movement occurs on smooth surfaces.

5. Speed and Efficiency

Larger wheels allow for faster movement, which can be advantageous in time-sensitive environments. They cover more ground with each rotation, making transportation quicker.

Example: In logistics or distribution centres, where time is critical, using large castor wheels on carts can increase the speed of movement, saving time during operations. Smaller wheels, while adequate for tight spaces or light loads, may slow down movement in such fast-paced environments.

How to Choose the Right Wheel Diameter for Castors

When deciding on the appropriate wheel diameter, consider the following factors:

1. Surface Type: Larger wheels are better suited for rough or uneven floors, while smaller wheels work well on smooth, indoor surfaces.
2. Load Capacity: Ensure the wheel diameter corresponds to the weight of the load the castor will carry.
3. Ease of Use: For easier movement and less strain, opt for larger wheels when frequently moving heavy loads or crossing thresholds.
4. Floor Protection: If preserving floor quality is a priority, choose larger wheels that exert less pressure and reduce floor damage.