MTB vs Road Bike Helmets: 11 Differences & Why It Matters
Road cycling gear is visibly different from mountain biking apparel. This is very obvious in the headgear for each of the biking disciplines. Although helmets are the primary choice for both, bikers seem to stick to their respective dedicated kit. It may be for appearance and for safety, but either way, it’s true: MTB helmets are in fact different. But what are the concrete differences between mountain bike and road helmets?
Mountain biking helmets have a visor, a bulkier design, a low-cut rear and usually more weight than the more compact, aerodynamic, well-ventilated road bike helmets. While some safety features are shared, they are designed to handle very different types of crashes. Overall, better safety features like MIPS prevent more injuries than the helmet design.
Get-offs on steep, uneven terrain often result in bikers tumbling down the mountain with lots of rotational forces from trail obstacles grabbing the helmet. Every bit of coverage helps here. While on the road, crashed riders usually slide on the pavement after a particularly hard initial impact. It’s actually helpful if the helmet has space to move on the head to not transmit all of the impact force onto the head.
Road helmets are primarily required to absorb and distribute the initial impact, while MTB helmets need to have good all-around surface protection since the head can hit the ground at any one angle during a fall. Hits to the back of the head are rather uncommon on the road.
#1 Helmet visor or peak
The most obvious visual cue distinguishing mountain bike helmets from their road and urban counterparts is obviously the long visor. It’s what’s recognizable across all MTB disciplines, for half-shell and for full-face helmets alike. Although they are responsible for the traditional look, they aren’t just for show either. Helmet visors or peaks have very specific purposes important to mountain bikers, which I explain in detail here.
But the long visor isn’t the only feature that makes a mountain bike helmet.
#2 Ventilation ports
Another difference visible at first glance are the air vents. Road bike helmets are clearly on top here, both in size and number. And it makes sense. On the road the average speed is usually higher, while on the trails gravel, dust and dirt in the air are a real issue. Nothing you’d want to get into your helmet through big air vents.
If you’ve ever caught a bee with one of your vents, you know it’s not fun.
#3 Shape & design
Even if you can’t quite put your finger on it, road and MTB lids just seem to be designed very differently. Not just in the paint jobs and colors used, but in all shapes and accents.
There’re generally more edges on MTB lids with their traditionally very aggressive designs. Although some brands have come out with rounder designs recently, which helps with reducing rotational impacts.
On the other side, road helmets look more fluid, like a waterdrop in the overall shape. And it’s no coincidence. It’s the ideal design for aerodynamics. And while helmets can look cool, that’s obviously not their primary function
#4 Back-of-the-head protection
Mountain bike helmets also feature a lower-cut rear. This is partly due to fitment and a secure fit. The ratchet system at the back to micro-adjust for an optimally tight fit is universally used in all helmet types.
The main benefit is the added protection to the back of the head, which comes in contact with the ground more likely in off-road terrain than on smooth pavement. It also helps to reduce the wobble when bombing down a rough track when some head shake is inevitable.
Road helmets have started to adopt the low-cut design recently. But the overall contact area between helmet and head is only one aspect of protection.
#5 Over-ear designs
With more area covered on the rear, further extension towards the front is not rocket science. Also, something not seen on roadie lids. Helmets with over-ear designs even offer some protection to the jaw line without a full chin bar around the front.
Although, access to your earbuds is drastically limited …
#6 Chin bars
When the going gets rough, additional protection for the lower part of the face is a must. On the road, this is a non-issue. The downsides to breathability, weight, and aero overweigh the added benefit of full-face protection. That’s why they’re only used for mainly downhill riding.
Chin bars can’t even be optionally fitted on road helmets, which is possible on some newer MTB helmets. Riders thus have the choice between either regular full-face helmets (here’s the one I chose) or convertible helmets like the Giro Switchblade I use.
#6 Safety & injury protection
The differences in overall design lead to varying protective characteristics. While mountain bike helmets generally offer more head coverage, road helmets have better lab test results regarding brain injury prevention.
This is for two reasons I’ll explain in detail below. The gist of it is: Different types of riding require different types of protection. The helmets for each discipline are designed for different purposes and common crash situations.
The core safety technologies, however, are the same in the top-end models. One welcome onnovation over the recent years is MIPS or a proprietary variation of it. While brands give their system their own cool-sounding marketing names, the principles are the same.
This Multi-directional Impact Protection System (MIPS) technology is basically a helmet insert designed to create a slip-plane layer between the helmet shell and the biker’s head. In case of a crash, the slip plane reduces rotational forces to the head which are a main cause for concussions and brain injuries for cyclists.
Basically, its rubber knobs sitting in between the hard outer shell and the inner lining actually sitting on the head and well worth the extra price.
#8 Overall weight
With more actual material to the helmet, MTB helmets are bound to be heavier. Most of this extra weight is contributed by the bulky design with a thick shell and the expanded rear.
This is also a major reason why there’re specific cross country MTB helmets available, that look and feel very similar to road lids. Without visor and with the overall sleek designs, only the low cut rear reminds of the mountain biking roots.
#9 Aerodynamics
Low wind resistance is a key component of road cycling. Less so for mountain biking, where most of the time is spent riding uphill at a slow pace. The overall waterdrop shape, no visor and a slim profile all contribute to a good aero performance.
#10 Chin strap
This is a minor detail, but something that’s sure to get hung up when putting on an MTB helmet for the first time. While most road bike lids and some MTB lids have a regular buckle closure, a D-ring design is also common – especially on beefier helmets for gravity ridings like downhill, enduro and freeride. There is practically no way this system is going to open with force or by accident.
#11 Goggles or sunglasses compatibility
Proper eyewear for the job at hand is crucial. Not only to keep the vision clear, but also to keep unwanted objects (and sun rays) away from the eyes. It’s more or less mandatory gear for any cyclist and head gear is designed with either goggles or sunglasses in mind.
Needless to say, goggles need 2 inches of even surface going from the sides over the rear for the straps to sit securely. And a bit of clearence from the eye brows to the top of the helmet. Most MTB helmets can be worn with goggles, only some with sunglasses. Comfortably that is.
Any over-ear and full-face helmets will lead to pressure points on the frames of regular sunglasses. Some glasses are sleeker and designed to be worn under helmets. So a combination is still possible.
Like road bike glasses, they tend to come with bigger lenses, that go right up to the helmet.
Can MTB helmets be used for the road?
Mountain bike helmets can generally be used for road cycling. In terms of safety, they are suitable. Though, they may not have the improved aerodynamics, ventilation, or weight a dedicated road helmet can provide. With that compromise, MTB-specific helmets are a great option for an all-rounder helmet.
So, if you need to limit your budget and only want to own one helmet for all the riding you do, this may be the way to go.
As a matter of fact, I’ve ridden bikes on streets with my mountain bike helmets for a long time. Even full-on road bikes. And sometimes with the big MTB goggles. It was just a sure way to prevent anything from getting into my sensitive eyes. The looks I got for that fashion statement were definitely earned!
But the road helmet I got since those days is far more enjoyable and not as hot to wear on the road bike.
Can you use road bike helmets for MTB?
It’s not recommended to use a road biking helmet when mountain biking due to the reduced area protected around the head. Crashes on smooth roads are different from impacts on steep, uneven terrain. That’s why there are specific helmet designs for specific types of biking.
In terms of the requirements for riding and crash scenarios, they are designed with two completely different purposes in mind.
Also, neck braces for MTB are designed to only work with full-face helmets but are also not relevant for road cyclists.
Are MTB helmets safer?
Mountain biking helmets are generally safer in uneven terrain by protecting more area of the head. However, on even road surfaces, road cycling helmets offer overall better brain injury prevention; according to standardized lab tests from STAR protocol.
In this 2019 study 30 helmet models from 14 brands were put to two repeatable impact tests. It’s important to note, that all of them were half-helmets and any peaks or visors were taken off. The helmets were always impacted at an angle towards the front to see possible damage to head and neck.
This means they did not account for tumbling or hits besides the upper portion like towards the back of the head, jaw or face. Still, this leaves one pressing question unanswered:
Why are road cycling helmets better at brain injury protection?
Since they are slimmer in design, road bike helmets tend to break more easily than bulkier MTB lids. Helmets are designed to absorb some of the kinetic energy by breaking. Additionally, due to their lesser contact area with high-cut rear portions they can slip on the bikers’ head, absorbing some of the rotational forces often connected to concussions.
Similar to what the MIPS is designed to do. It was also explicitly stated, that helmets with MIPS (or similar technology) perform better than helmets without such safety features.
Again, these findings stem from laboratory tests, where impacts were always experienced to a part of the crash-test-dummy’s head covered by a helmet.
In all of this, one important fact needs to be clearly stated here:
No type of bicycle helmet can prevent concussions entirely. New technologies like MIPS, however, can significantly reduce the risk of concussions in case of an impact to the head.
