In 2011, Wheel Solutions Ltd assisted with an investigation into wheel detachments on touring caravans.  In conjunction with OEM manufacturers, component suppliers and the National Caravan Council, WSL was engaged to examine the “joint” between the hub, wheel bolts and the wheel.

Tourer caravans today are considerably more advanced than those produced a decade ago:  Content has increased; braking systems are more sophisticated; trailer stability control systems are available; larger wheel diameters and lower profile tyres are now fitted and new innovative caravan manufacturing methods are involved.  Yet, the original inherited wheel bolt utilised had never been technically investigated.

In conjunction with a European bespoke fastener manufacturer, world renowned bolt technologists, specialist testing facilities and WSL’s determination to research and design a ground-breaking bolt that would perform with a high safety margin in this demanding environment, we developed the WSL Safety Bolt.

Features:

• Bespoke floating collar– specifically designed for the caravan industry 
• Security/locking wheel bolt head 
• High performance anti-friction and anti-corrosion 2-part surface finish

Benefits:

Assists in the prevention of: 

• Wheel Detachment
• Bolt Loosening
• Wheel Theft

Increasing the clamping force forms part of maintaining sufficient strain in the joint.  Also, bolt extension (stretch) is an area that is vitally important to overcome settlement (embedding) of the mating surfaces, i.e. the hub face and the wheel, and will also combat any potential “creep” of paint or lacquer especially under higher temperatures created through braking or stability control. 

With data gathered from Bolt Science and the component manufacturers, the total extension on the WSL Wheel Safety Bolt is 2-3 times the total dimension of any potential creep and the embedding process!  (Applied torque 130 Nm.)

The huge increase in clamping force and bolt extension was tested and verified by Bolt Science (one of the world’s leading specialists on bolt training and technology).

With data gathered from Bolt Science and the component manufacturers, the total extension on the WSL Wheel Safety Bolt is 2-3 times the total dimension of any potential creep and the embedding process!  (Applied torque 130 Nm.)

The huge increase in clamping force and bolt extension was tested and verified by Bolt Science (one of the world’s leading specialists on bolt training and technology).

Once the design had been finalised, prototype tooling produced, prototype bolts produced and positive testing at Bolt Science had been concluded, it was time to test the bolt, hub and wheel in both a simulated test environment and ultimately on a caravan!

At 1,583 test miles on the endurance and testing Millbrook Proving ground the wheel bolts were checked (cold) and all bolts recorded their original torque setting of130 Nm without movement.

The WSL Safety Bolt is the first bespoke wheel bolt designed for the caravan industry with one of the UK’s leading tourer caravan manufacturers supplying the Bolt as a standard factory fit on all caravans fitted with alloys.

It represents a huge leap forward in technical development on a component that has stood still for decades.