Dirt bike helmet technology has progressed significantly in the last decade, with a number of established brands introducing new advancements that are ultimately making the sport safer. At the forefront of helmet development is Bell, who offers one of the most sophisticated safety systems on the market with its Moto-9 Flex.

Initially introduced in 2015, Flex energy management is a first of its kind, three-layer impact liner designed to manage energy from three potential impact scenarios – low, mid and high-speed.

Utilising a segmented construction, the Flex technology automatically allows the Moto-9 to conform to a rider’s head for a better fit and more predictable energy management.

“Progressive layering is a method for managing a wide variety of impact velocities, we’re redoing that by combining three different materials that each have their own purpose,” Mike Lowe, VP of Bell product creation, explained. “A good analogy for progressive layering is a trophy truck – they’re going over small, medium and big bumps.

“Our helmet has three different materials – primarily the EPO and EPP are doing the small and mid-size bumps, and EPS is doing the big energy impact. When you put them all together, we’re able to get a system that performs across the board in impact protection.

“Normally helmets are a rigid head form – it’s a symmetrical head form that’s smooth, and people’s heads are far from that. The Moto-9 Flex with its inner liner segmented allows it to adapt to different proportions.”

A ‘slip zone’ within the impact liner allows for subtle movement between the inner layers, and works to reduce rotational energy transfer from angular impacts. Rotational impacts can lead to concussion and serious head trauma, however the ‘slip’ characteristic of the Flex liner assists in reducing such injuries.

“The system is intended to reduce rotational injuries – in a rotational impact, you’re hitting the ground – or any other foreign object – at an angle, and that causes your head, your brain, and your skull inside to rotate, and that can cause serious injuries,” said Jason Lichtman, Bell Helmets senior mechanical engineer.

“The Moto-9 Flex is designed with an inner liner system that can rotate to the inner and outer layers. Those critical first milliseconds where the inner line is slipping relative to the other two liners is crucial to reducing the transfer of rotational energy.”

With the new segmented and flexible liner in the Moto-9 Flex, Bell was able to add its proven Velocity Flow Ventilation system, making it incredibly breathable, while also reducing the overall weight of the helmet.

The Moto-9 Flex is also paired with additional protective features, including a Flying Bridge Visor system, which with no centre-mounted screw, channels energy from impacts through the flexible visor, acting as a crumple zone away from the helmet and riders head.

The complete Bell Moto-9 with its 3K carbon shell and Flex energy management makes it one of the safest and most protective dirt bike helmets available. The company just released its 2020 range, offering a selection of fresh designs for the new year. For more information, www.bellhelmets.com.