Measuring replacement wheels and castors

In this section

• How to measure a solid wheel
• How to measure a pneumatic/air-filled wheel
• How to measure castors

Useful tools for the job

To measure up a replacement wheel or castor, you’ll want to have:

• The old wheel that needs replacement, including the castor fork, 
• The application it’s come from nearby to check measurements
• A sturdy, flat surface
• Tape measure
• Callipers
• A pen or pencil (more on that later)

Some useful definitions 

• Wheel - a fixed wheel on an axle
• Castor - a wheel mounted onto the application directly through a range of mounting plate or bolted configurations. Often sits under the application, although there are situations where they’re positioned to the side or above.
• Tread - the outside of a wheel that touches the ground - tread varies by thickness, width, material, grip and even noise. 
• Mounting Plate - a (usually metal) flat piece that is bolted into the application in order to attach the castor securely.

We’ll go into more detail within each of the specific wheel measurement guides!

Weight capacity needed

Before you start measuring up, it’s always a good idea to figure out the maximum weight that your application (such as a trolley) will need to handle. Remember, weight shifts and distributes during load and offload, as well as when the application is moving up and down inclines. So it’s a good idea to leave yourself enough additional weight capacity for a strong, free-rolling handling experience.