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Why Are Road and Mountain Bike Helmets Different?

When cycling, your helmet is the most crucial safety equipment. It protects you from severe head injuries if you fall. However, several types of helmets exist, including road and mountain bike helmets. When choosing your helmet, it is important to know why road and mountain bike helmets differ.

Road and mountain bike helmets primarily differ because of the different riding styles you choose and their location. Road bike helmets are mostly worn when riding on paved roads in plain areas, whereas mountain bike helmets are worn for off-road riding in areas with rough terrain and obstacles.

Road bike helmets are designed to be lightweight, well-ventilated, and aerodynamic to reduce wind resistance. Although mountain bike helmets are ventilated, too, most styles have extended head coverage to protect mountain bikers as they fall backward.  

It is important to wear a helmet on every ride for your safety, no matter how long or short. Therefore, you must invest in a good helmet if you are going to do a lot of cycling. So, what makes road and mountain bike helmets different? 

Related: Mountain Bike Helmet: Open or Full Face?

road bike vs mountain bike helmet

How Are Road And Mountain Bike Helmets Different?

We will begin discussing features that make road and mountain bike helmets differ as they are designed for different purposes. 

Helmet Visor Or Peak

This is the most common way to differentiate between a road bike helmet and a mountain bike helmet.

The latter has an extended visor or peak. This is a removable shield made of plastic or carbon and is attached to the front of the helmet. It protects against the harsh sun, rain, branches, trail debris, and impact absorption.

Mountain bike helmets have a visor to prevent riders from getting hit in the face or eyes if something falls from above or if they fall into the ground. A visor’s effectiveness increases if riders tilt their head downwards if hit by an obstacle.

Road bike helmets do not have a visor because there are lower chances of branches and trail debris when cycling on a paved road. Also, your eyes do not need much protection on the road. As most road bike riders wear goggles, there is not much need left for a visor.  

Ventilation Ports

Another visible difference between road and mountain bike helmets are the air ventilation ports. Road bike helmets have more air vents than mountain bike helmets and are also larger in size.

This is because the average speed is usually higher when cycling on a straight paved road than on mountainous terrain. This means that you are more likely to feel hotter when cycling for long hours. More air ventilation maintains your body temperature and also prevents the helmets from getting stinky because of sweat.

Road bike helmets need to have ventilation sliders too. Thus, you can close some of them when riding during the winter and protect yourself from getting too cold.

Mountain trails have more gravel, dust, and dirt in the air. Smaller and lesser ventilation ports in mountain bike helmets prevent these from getting inside the helmet and into your eyes and mouth. 

Lesser ventilation ports also keep riders warm when cycling in colder terrains because a higher airflow through the helmets may make the riders feel excessively cold.

Shape And Design

The shape and design of road and mountain bike helmets also tell them apart. A mountain bike helmet generally has more edges. This is to provide maximum protection to riders in case of a direct impact with the ground or gravel trails falling from above.

Contrastingly, road bike helmets look more fluid. They do not have rough edges and are more circular to keep riders well-protected while maintaining high speed on plain roads. 

They are also designed to be more aerodynamic so that wind molecules do not abundantly collide with the helmet. This reduces air resistance and maintains high riding speed.  

road bikers wearing helmets

Back-Head Protection

Another way to distinguish between a road bike helmet and a mountain bike helmet is their back-of-the-head protection. Mountain bike helmets have a lower-cut rear. This ensures that the helmet fits riders perfectly.

A lower-cut rear’s main benefit is adding protection to the back of the head. This is because the back of the head comes into direct contact with the ground when you fall backward on off-road terrain. So, when your head is fully covered inside the helmet, there will be fewer head injuries.

The cut also helps reduce the head’s shaking as riders come down rough terrain. This increases head stability, and riders can better navigate their way even if speed increases as they come down.

Although road helmets usually have a higher cut back end, they have started to adopt the low-cut design as it increases safety on a paved road too.

Over-ear Designs

As mountain bike helmets have a lower rear, it is essential to have more extension at the front. This maintains the helmet’s balance and prevents it from falling off mid-ride.

Helmets that have an over-ear design keep the jawline enclosed and offer it more protection. This feature is absent in road bike helmets.

Moreover, over-ear designs limit access to your earbuds. This is important because, in case of a fall on mountainous terrain, you may fall on the side of your head and damage your ears. Over-the-ear designs protect your hearing by reducing this risk.

Chin Bars

Mountain bike helmets offer extra protection for the lower part of your face by including chin bars. They cannot even be optionally fitted on road bike helmets because they are not designed to include chin bars.

However, they are necessary for off-road terrains, especially during downhill riding. This is because full-face protection will reduce injuries to a rider in case the speed increases too high or an obstacle causes the mountain bike to topple.

Safety And Injury Protection

A road bike helmet and a mountain bike helmet have varying protection levels because of the aforementioned design features. Although mountain bike helmets are designed to offer more head coverage, road bike helmets have been tested better to prevent brain injury.

A new technology part of road bike helmets is the Multi-directional Impact Protection System (MIPS). This helmet insert is designed to create a slip-plane layer between the helmet’s shell and the biker’s head.

In case of a crash, this slip plane reduces rotational forces to the head. As these are the basic causes of brain injuries and concussions for cyclists, road bike helmets prevent brain injuries better than mountain bike helmets. 

Weight Of The Helmet

Mountain bike helmets are made up of more material and are heavier than road bike helmets. The thick shell and lower-cut rear add more to the extra weight. However, helmet weight also heavily depends on the company and model of helmet that you buy. 

Goggles And Sunglasses Compatibility

When cycling, it is vital to wear the proper eye-protection gear. This ensures clear vision for riders and prevents sun rays and unwanted objects from getting into the eyes. Goggles require 2 inches of even surface going from each side over the rear for their straps to be secured in place.

Most mountain bike helmets can be worn with goggles, but not many can be comfortably worn with sunglasses. This is because the long visor and over-ear designs of mountain bike helmets will lead to added pressure points on the frames of regular sunglasses. However, sleeker sunglasses can still be worn under them.

Having discussed features that make a road bike helmet and a mountain bike helmet different, we will now consider whether we can use the two interchangeably.

Here’s a buyer’s guide for you to consider: 

Can A Mountain Bike Helmet Be Used For Road Cycling?

Yes, a mountain bike helmet can be used for road cycling as they are suitable for safety. However, the lack of aerodynamic and ventilation features and more weight can make them less efficient.

Mountain bike helmets are relatively cheaper than road bike helmets. So, if you can compromise on poorer ventilation, mountain bike helmets can prove to be good all-rounder helmets. Let’s see whether a road bike helmet can be used for mountain cycling.

Can A Road Bike Helmet Be Used For Mountain Cycling?

No, using a road bike helmet is not recommended when mountain biking. This is because road helmets have reduced protection air around the head. Crashes and accidents on smooth roads are less dangerous than direct impacts on steep and uneven terrain. Road bike helmets are not designed to cater to these impacts.

In terms of their design, wearing a road bike helmet when riding on off-road terrains will make riders more vulnerable to severe head injuries. Having talked about which helmets are safer to use alternatively, we will begin discussing bike helmet fit and comfort. 

How To Check Bike Helmet Fit And Comfort

When choosing between a road bike helmet and a mountain bike helmet, a good fit is vital. If your helmet does not fit properly, it will have reduced effectiveness if you crash.

Find Your Head Circumference

To find the fitting size bike helmet, start by measuring your head circumference. To find your head circumference, wear a flexible tape measure around the largest part of your head. This is usually about an inch above your eyebrows. 

Another way to measure head circumference is to wrap a string around your head. Then, measure the length of the string with a ruler or a yardstick. 

Bike Helmet Sizes

Bike helmets come in different sizes to cater to a larger customer base. These are mentioned in the table below.

Helmet SizeMeasurements
Extra SmallBelow 20 inches (51 cm)
SmallBetween 20 to 21.75 inches (51-55 cm)
MediumBetween 21.75 to 23.25 inches (55-59 cm)
LargeBetween 23.25 to 24.75 inches (59-63 cm)
Extra LargeAbove 24.75 inches (63 cm)

The size ranges mentioned above may slightly vary for different brands. You should always double-check the head circumference of your chosen helmet size. 

Also, it is better to try different helmets at a store to see which fits perfectly instead of buying one online, as you may order the wrong size if you have not measured your head circumference correctly.

You should go for the smaller size if you are in between sizes. This is because you can tighten a smaller helmet to make it fit securely, but if the helmet is too big, it will feel tight while riding and make the experience uncomfortable.

Adjustments will be needed even if you buy the right-sized helmet. Let’s talk about adjusting your chosen bike helmet to fit well.

How To Adjust A Bike Helmet

As you will be wearing your helmet for long hours, it is vital to ensure you are comfortable wearing it. To adjust your bike helmet, follow the steps below. 

Adjust The Tightness

Most helmets have an adjustment wheel that can be fully opened to put the helmet on your head. Then, twist the wheel until getting a snug fit so that there is no room left for it to move. 

Fit systems vary for different helmets. Some helmets adjust fit snugness using interchangeable interior foam pads. 

Tighten The Chin Strap

Next, you must buckle and tighten the chin strap. As they rest under your ears, the straps should form a V-shape. If they do not create a comfortable V, you must adjust the buckle under each ear until they do.

Open Your Mouth Wide

When the chin strap is buckled, you need to open your mouth wide. As you do so, the helmet should press against the top of your head. 

If it does not happen, it means that your helmet is loose, and you must strap it more. However, be sure not to over-tighten it, as you may get uncomfortable mid-ride.

Final Takeaway

Road and mountain bike helmets vary for use on different riding paths and terrains. Road bike helmets are lightweight and well-ventilated for use on paved roads, whereas mountain bike helmets have features such as a visor for more protection on off-road riding. You should check the helmet size carefully before buying one.