Mountain biking is wilder than ever. Modern bikes are more capable than at any point in the sport’s history, enabling riders to cover ground faster, tackle steeper terrain and ride increasingly rough trails.
From cross-country to downhill, riders are hitting bigger features and travelling faster. The result is a sport where the forces acting on riders – and particularly their heads – can be significant.
While bike tech and geometry have evolved dramatically to improve performance and control, understanding what happens to a rider’s brain during those rides – and the inevitable crashes – is far less straightforward.
That’s where the HIT Connect device comes in. Developed by head-impact monitoring company HIT, the small sensor mounts to the back of a helmet and records the forces acting on a rider’s head.
Used by downhill World Cup racer Reece Wilson and the AON Racing team, as well as road riders such as Tao Geoghegan Hart of Lidl–Trek, the device measures both individual impacts and the cumulative forces riders experience.
The aim isn’t to diagnose concussion directly, but to give riders objective data that could help them better understand the strain their brain experiences while riding.
Why understanding head impacts matters
Concussion has become an increasingly visible issue in cycling, particularly in gravity disciplines such as downhill and enduro where speeds and impact forces are high. Several high-profile riders have spoken publicly about the challenges of recovering from head injuries.
Downhill World Cup winner Tahnée Seagrave has been open about her experiences with concussion. A crash in 2022 led to a prolonged recovery period that forced her to step away from racing while dealing with ongoing symptoms.
Similarly, former downhill world champions Myriam Nicole and Camille Balanche have spent significant time away from racing while recovering from concussion.
On the men’s side, riders such as Finn Iles have missed race weekends due to concussion symptoms, while crashes in road racing have highlighted the issue more broadly – with Tom Pidcock experiencing head injuries during competition.
The difficulty with concussion is that symptoms aren’t always obvious immediately after a crash. Riders often feel capable of continuing, only for dizziness, headaches or cognitive symptoms to appear later.
That uncertainty is one reason devices such as the HIT system are attracting attention. By measuring the forces acting on a rider’s head, the technology aims to provide objective information that riders and teams can use to make better decisions after a crash.
Importantly, the system doesn’t diagnose concussion itself. Instead, it highlights potentially significant impacts and provides data that could help riders decide when it may be wise to stop riding and seek medical advice.
What is the HIT device?
The HIT device is essentially a head-impact monitor designed to measure the forces experienced by a rider’s brain during riding.
Mounted on the back of a helmet, the device contains accelerometers that track both linear and rotational forces acting on the head.
According to HIT founder Euan Bowen, the system records the forces riders experience throughout a riding session and processes them through a connected smartphone app.
“The HIT device is basically a head-impact monitor,” he explains. “It gives you accelerometry for G-forces and rotational forces to the head. It records both single impacts and the cumulative impacts over the course of your session.”
The app then analyses that data to show riders how much impact load they’ve experienced during a ride, a training day or even an entire race weekend.
How the HIT app works
All of the impact data recorded by the sensor is transmitted to a companion smartphone app.
Riders simply connect the device to their phone, start recording before a ride and leave the device to log data throughout the session.
After the ride, the app provides a breakdown of the forces experienced, including:
- Total cumulative G-force
- Maximum single impact
- Maximum rotational force
- GPS ride data
- Speed, elevation and ride duration
Impacts are also categorised using a colour-coded system. Green represents normal riding forces, while amber and red alerts indicate increasingly severe impacts.
“We flag up the one-off impacts as well,” explains Bowen. “If you’ve had a big hit in the amber or red zone, that’s a threshold where you may have a higher chance of developing concussion symptoms.”
The goal isn’t to diagnose injury, but to remove some of the guesswork riders face after a crash.
“It eliminates the grey area,” he says. “It’s objective data you can actually analyse.”
The app can also display impact locations on a GPS map, enabling riders to see exactly where on a trail or race track larger impacts occurred.
Why cumulative G-forces matter
While individual crashes producing large impacts are the most obvious concern, one of the key ideas behind the HIT system is tracking cumulative impacts.
Just as muscles become fatigued after repeated strain, the brain may also experience fatigue from repeated forces over time.
During a typical downhill World Cup race weekend, riders can complete a surprisingly high number of runs.
“Anywhere between 12 and 15 runs over the course of a weekend,” says Wilson. “Some riders might even get up to 18 or 20.”
Each run exposes the rider to multiple impacts – from landing jumps to smashing through rock gardens. Even seemingly minor hits can add up quickly.
“You might get to run 11 or 12 on a brutal track and start feeling a little bit off,” Wilson explains. “Now we can look at the data and see we’re maybe up around 250 or 300 cumulative Gs, and maybe it’s just that my brain’s a little bit tired.”
That information can influence how riders approach the rest of the weekend.
“In that situation we might not do the last run,” he says. “We might just take the kit off and go for a walk instead.”
How much force are riders experiencing?
In the context of the HIT system, one key metric riders monitor is total accumulated G-force during a session.
According to the company’s research, around 300 cumulative Gs appears to be a threshold where subtle cognitive changes may begin to appear in athletes.
“We’ve found that around 300G for adult males is where you start to see cognitive decline,” says Bowen.
That doesn’t mean riders are injured, but they may experience subtle changes in performance.
“It’s things like ocular motion, balance and spatial awareness,” he explains. “Those things might just be a little bit off.”
For a downhill racer riding at full speed on a technical track, even a small drop in sharpness could increase the likelihood of making mistakes.
One of the most surprising aspects of the data is how large some of the forces can be.
Wilson recalls recording a single impact of 18G simply from hitting a rough section of track.
“I pulled 18Gs just hitting a fire road,” he says. “Just one slap on the road.”
Those forces quickly accumulate over the course of a run that might last four minutes. Add multiple practice runs across several days and the numbers can climb rapidly.
That’s why understanding cumulative load is becoming increasingly important for teams.
“The more you use it, the more you begin to understand yourself,” Wilson says. “You start to see where your cut-off point might be.”
Using impact data to guide training
One of the most practical uses for the HIT device may be helping riders manage training loads.
Professional riders often train across multiple disciplines, including downhill, motocross and gym work. Impact monitoring can help them understand when their brain may need additional recovery time.
“For example, you might do a hard day on a motocross bike followed by a couple of downhill days,” Wilson says.
“Then the next day you’re thinking, ‘I’m not feeling quite right’. Now you can look at the data and see maybe you accumulated more impact load than you thought.”
That information can help riders decide whether to continue training or take a recovery day.
Who is the HIT system for?
Although the device is currently being used by professional downhill racers, the system is designed to be accessible to a much wider range of riders.
“It’s available from grassroots level all the way up to elite riders,” says Bowen.
For everyday mountain bikers, the value of the device lies less in performance optimisation and more in awareness and decision-making after a crash or heavy impact.
Many riders have experienced a situation where they crash, get back on the bike and continue riding, only to feel unwell later in the day. Concussion symptoms can sometimes take time to appear, making it difficult to judge in the moment whether a hit to the head was significant.
A device such as the HIT Connect offers riders objective data about the forces involved in an impact, helping remove some of that uncertainty.
For riders who spend long days at bike parks, and riders on their annual MTB holiday squeezing in multiple days in rough terrain, cumulative impact tracking could also provide insight into when fatigue may be building – something that may increase the risk of mistakes on the trail.
Parents of young riders may also find the system useful, because the app enables impact data to be shared or monitored remotely.
A new way to think about brain health in mountain biking
Mountain biking has long embraced technology to improve performance. Power meters transformed training in road cycling, while suspension and geometry innovations have revolutionised bike handling.
Impact monitoring could represent the next frontier – not for speed, but for understanding rider safety.
“We track heart rate, steps and performance metrics in sport all the time,” says Bowen. “This is just another method of helping athletes and riders understand what their body is going through.”
As mountain biking continues to push the limits of speed and terrain, tools that help riders understand the hidden forces acting on their bodies could become increasingly valuable.
The HIT device might be small, but it represents a growing effort to better understand one of the most complex and important parts of riding: the brain.
