In contact sports, concussion is categorised as the silent killer. Crashes are part of off-road riding and the best mountain bike helmets are a good way of ensuring you stay safe on the trail. Soft tissue brain damage is where concussions manifest. And over time, that soft tissue damage compounds and can trigger debilitating health conditions. 

“But my helmet will protect me against anything and everything, right?” Well, that's exactly where the debate has raged for the last decade and a bit, regarding helmet technology and concussion mitigation. 

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The core off-road cycling helmet is designed to prevent blunt-force impact trauma but you could also suffer a soft-tissue brain injury with no trace of blood or even external bruising - and that’s when things can get very dangerous. A Mips or Multi-directional Impact Protection System is a low-friction layer located between the EPS and inner helmet liner that reduces rotational impact forces. This helps protect your brain from concussion and trauma.

Read on to learn all about Mips, how it works and why your next helmet needs to include it.

Rethinking helmet design – from the inside

2021 bell super air mips spherical detail.jpg, by Liam Mercer

Traditional helmet design focuses on an extreme over-the-handlebar crash event, with a rider landing directly on their head in a nearly inverted impact posture. Although these crashes happen, they are exceedingly rare and usually only apply to extreme mountain bikers, participating in freeride events like Red Bull Hardline. 

A more data-centric approach has evolved in helmet design since the late 2000s. Curiously, the presence of action cameras on riders, such as GoPro’s hero range, has helped provide corroborating evidence and data of real-world crash dynamics. And the consensus is that off-road riders, especially mountain bikers, crash very differently than what has been assumed. 

Although any crash is a bewildering and dramatically confusing event, you are likely to separate from your bike in a lateral instead of longitudinal motion. Simply, you will probably slide or high-side off the side of your bike, instead of projecting over the handlebars. And that has enormous implications for how your helmet should help protect against concussions. 

The legacy cycling helmet design is all about road riding. And on a smooth stretch of road, there’s a lot less to impact, when you crash. Off-road? On a singletrack mountain bike descent, every few yards, there’s a rock, root or tree ready to awkwardly impact a ragdolling rider. 

The data logic isn’t difficult to fathom: mountain bike crash speeds might be much lower than on a road bike but the number of objects that could impact your head is higher. And it is exactly that unpredictable impact angle with a rock, root or tree, that creates the soft-tissue brain damage risk. 

How does Mips work?

2022 oakley drt3 mips sweat guard.jpg, by Liam Mercer

How to solve the concussion risk in off-road riding? The answer is Mips. A Swedish patent that has gone from peripheral snowsport helmet technology to becoming a nearly universal product feature on most cycling helmets. 

Swedish neurologists and medical engineers developed Mips. In theory, it is deceptively simple. If you look inside a Mips-equipped helmet, you’ll notice yellow material between the padding and internal shell. That’s the Mips impact liner, also known as a slip-plane – which is quite an accurate description. 

Mips allows your helmet to rotate and move at the point of terrain impact, dispensing crash energy and reducing strain on the brain. The sudden jerking motion a rider’s head experiences when crashing and impacting an unsighted rock framing the trail, is where Mips claims to be at its most effective. 

How much does a Mips liner move? Depending on the direction of rotation, it is rated for 10-15mm of slip movement. This reduces angular impact forces and their sudden accelerative influence on the brain – decreasing concussion risk.

Are Mips helmets safer than non-Mips versions?

2021 bell super air mips spherical logo .jpg, by Liam Mercer

As with any technology, there must be a cost counterbalancing the benefit, right? 
Mips helmets cost more than structurally similar helmets with the same features. What’s the difference?

It varies by brand and model, but as Mips has standardised across the industry and created scale (with 120 brands now using it), the pricing difference between helmets with Mips, and those without has narrowed.

There’s also the question of ventilation. This isn’t much of an issue for northern hemisphere riders, with short summers. 

A Mips helmet will slightly reduce airflow and ventilation for southern hemisphere riders or off-road cyclists who vacation in semi-arid regions (the southwestern United States, Africa, Australia or the Iberian peninsula). 

Is a Mips helmet worth the investment?

Smith Convoy MIPS helmet-6.jpg, by Rachael Gurney

There’s no way you can guarantee an off-road riding lifestyle without crashing. The only way to completely reduce crash risk is to ride on your indoor trainer at home. 

Off-road cycling is about mindfulness, the healing presence of nature and healthy escapism. And accessing all those riding benefits comes with risk. But what you can do to reduce a crash's damage is have all the possible layers of safety technology present. And Mips is one of those. 

Worth the cost? Off-road riders have realised that active bleeding is the only indicator of a serious crash and brain injury. And that’s what Mips is. You might be lucky and never feel that slip-plane liner’s movement during a crash, but having it there, is a smart idea - just in case. 

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