Technical examination of wheels and tyres
Individual product requirements
Swivel wheels and running wheels / impellers are essential equipment features of smaller vehicles for transporting people or objects. The parameters for the individual testing of wheels and tires best reflect the special operating conditions of the underlying product. Aspects from the application of products such as bicycles, scooters as well as many technical aids such as wheelchairs and rollators but also buggies and baby carriages, chairs, armchairs and couches are implemented.
Steering wheels / Swivel wheels
Steering wheels / Swivel wheels / Castor wheels are usually non driven. They are automatically steered into the desired direction of the product by means of vertical swiveling.
Castor wheels are available in many sizes and configurations with solid rubber tires (e.g. polyurethane) or pneumatic tires. A caster assembly includes the wheel and tire, bearing, fork, shaft connection, and shaft-hub configuration.
Important factors when selecting a steering wheel are the Obstacle climbing ability, the rolling resistance, foot interference and "flutter" of the wheels - with reference to the user and application environment.
Steering wheels are exposed to a variety of stresses and strains. The main part of the acting forces is carried by the wheel, the fork and the stem bolt. Separate individual tests enable a targeted selection of suitable steering wheel configurations for full functionality during the expected service life.
A running wheel means the entire assembly (rim, tyre, tube, hub, axis) of the tracking axis (usually the back wheels) of mobile products. The most common designs include spoked wheels and composite or compound wheels that are filled with air, polyurethane or foam inserts.
The size and number of spokes / struts as well as the material for filling depend on the type of product and the intended use. The size of the wheels and the frame define the distance from the seat to the ground, which significantly influences the various characteristics (e.g. tipping stability, ergonomics) of a product.
Berlin Cert offers a wide range of methods for the inspection of wheels & tyres
- Rolling resistance: We determine the force required to move the auxiliary means on different surfaces with different tyres, wheel diameters, wheel axis positions, camber settings and inclinations of the driving surface.
- Strength and positional and form stability of fork, bearings, fasteners and wheel spokes
- in demanding application environments (excessive humidity and heat, dirt, uneven ground, etc.)
- with different wheel axis positions and load scenarios (intensive use, vertical and horizontal forces, vertical and horizontal impact loads)
- Ergonomic aspects and strength of different wheel axle positions (ease of use, operating forces, accessibility, clamping & pinching)
- Durability of tyres (resistance to abrasion, detachment, tyre breakage, tyre cracking) and effects of rapid ageing (bearings, forks, stem bolts)
The objective of the mechanical investigations is to obtain meaningful results for specific operating conditions of wheels with adaptable configurations of complete systems or individual parts. Furthermore, different installation variants including unintended use can be tested.