The best aero helmets can make a noticeable difference over a traditionally vented helmet and help you go faster for less effort
(Image credit: Abus)
The cycling world has become infatuated with aerodynamics. One particular brand even goes as far as to state that aero is everything. While that might not technically be 100 per cent accurate, aero helmets certainly provide benefits, a notion reiterated by the fact that the majority of the pro peloton use aero helmets for all but the hilliest of days.
The benefits provided by aero helmets have long been explored by time triallists, a discipline where innovation is rife and every possible time-saving measure crucial. However, over the past decade, the marginal-gains mentality has seen it filter onto the road, in turn leading to the creation of the aero road bike helmet.
In that time, the aero helmet has fast become a common sight on the heads of road cyclists of all abilities, as riders are sold on the prospect of higher speeds for fewer watts – cycling’s holy grail if you will.
The aero road helmet is easily distinguishable by its profile, often featuring a smooth frontal area with a decreased quantity of air vents. Occasionally the rear will extend to guide the passing air beyond the rear of the head with minimal turbulence.
With the reasonably large frontal area of a cycling helmet, it makes sense that the easier it can slice through the air, the higher the speed and less power output required. This is where a breakaway specialist might see the attraction and, of course, a time trialist, for whom that extra half a kilometer per hour could mean the difference between winning and losing.
This is also particularly attractive to cyclists who want to save as much energy as possible, such as sportive riders who have long distances to cover, sprinters who need the energy for that final huge effort, and even commuters who just want to get to work feeling fresher.
Things to consider when buying an aero helmet
There are a number of considerations that will affect your decision. We've outlined the important ones below.
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Safety
This should be the first consideration for anyone buying a new helmet. After all, the whole purpose of the cycle helmet is to protect your head in the event of an accident. All helmets in this test will have passed the relevant regional industry-required standards, however, others go beyond the call of duty by utilizing technological innovations such as MIPS (Multi-directional Impact Protection System), which is a 'slip-liner' that enables the helmet to rotate independently of the head during impact. This means that during angular impacts, more energy is absorbed by the helmet, rather than being transferred to the rider’s head.
Speed
More accurately, aerodynamics. The majority of helmet manufacturers will make aerodynamic claims about their helmets, usually a saving of power or an increase in speed, based from their own in-house testing. Sadly, we don't have a wind tunnel at our disposal, so we’re at the mercy of these claims and personal feel. We're aware feel is subjective, so where possible, we will try to standardise these claims to make them easily comparable.
Comfort
A helmet may make you ride faster but if you're stopping mid-ride to adjust the fit, then all of those precious seconds you've saved will be wasted. Of course, fit is very personal and, as such, we shan't focus too greatly on this.
Weight
The gradient at which weight has a greater effect on speed than aerodynamics is approximately six per cent. Based on this, for the majority of the time, weight should be a secondary consideration but one worth noting nonetheless.
Ventilation
Ventilation might not be the primary focus when searching for an aero road helmet, but it's a worthy consideration – especially for those riding in hot climates. Aerodynamics and ventilation in cycling helmets tend to have a degree of mutual exclusivity, however, some manufacturers claim to take advantage of the Venturi effect, which in short, states that air will accelerate when pushed through a small hole. This means that air can be guided into small air vents and out of the back dragging the warm air out to aid cooling. Our reviews below will outline whether the manufacturer has considered this, along with the number of frontal vents, however, vent size is also worth noting.
Aesthetics
Looks may be completely irrelevant to the performance of an aero helmet but it's still likely to be considered when it comes to making a purchase. Of course, it's completely subjective, so while this won't be a major consideration in our reviews, we may make the occasional reference to our opinion, and we will include as much detailed imagery as possible to ensure you can make an informed judgement.
A popular and well-revered helmet that can be used in all conditions and for a range of cycling disciplines
The Kask Protone is a well-revered helmet that strikes a perfect balance between aerodynamics and ventilation. The 12 large frontal vents offer a great amount of airflow across the head, while the smooth rounded profile at the back helps guide air beyond the head with minimal turbulence.
Kask's 'Octo Fit' system serves to offer a range of adjustability to fit all head sizes. This offers a secure all-around fit, that holds the head in a secure, but comfortable fit. There is also an eco-leather chin strap, along with 3D dry padding, which both serve to offer additional comfort.
While the omission of a slip liner might be off-putting to some, the Kask Protone still surpasses the level of protection required by industry standards, including 'EN 1078', 'CPSC 1203' and 'AS/NZS 2063'.
A well-ventilated helmet designed with CFD to create an optimal balance of weight, aerodynamics and ventilation
The POC Ventral Spin helmet is not necessarily the first you'd look to when seeking an aero helmet, however, it's a contender worth considering for those who include ventilation as part of the equation.
Unlike POC's previous aero helmet, which consisted of little more than their Octal being fitted with a solid outer shell, the POC Ventral Spin underwent considerable aerodynamic and CFD testing throughout its development. POC adopted a 'whole-helmet approach', which they claim has helped to enhance aerodynamic performance and decrease air turbulence. Additionally, the air-flow design has been optimised in order to increase ventilation and thus accelerate cooling.
Like most of the helmets in POC's line-up, the Ventral uses SPIN technology (Shearing Pad INside) to protect your brain against the effects of oblique or rotational impacts.
An aero helmet that looks equally at home on the morning commute as it does in a time trial
The Giro Vanquish MIPS is the one helmet in this list that would look equally at home in a time trial as it will on the road. Designed using CFD and wind tunnel testing, Giro make some rather tough-to-compare aerodynamic claims about the Vanquish. When compared to a Bontrager Ballista, the Vanquish MIPS (with visor) will supposedly save 12 seconds in a 40km TT at 400 watts, and removing the visor will cost you two watts. They also claim a saving of 62 seconds in a 180km TT at 250 watts.
A stand-out feature is undoubtedly the removable Vivid Shield visor. It easily snaps into place thanks to three strong magnets and can also be flipped and affixed upside down. It’s worth mentioning that finding the exact position one-handed can often take a bit of adjustment, although removing and reattaching the shield mid-ride isn't a common occurrence. It uses optics by Zeiss, and is suitable for all but the most overcast of conditions. The helmet also plays well with standard sunglasses, even utilising the outer two of the four frontal vents as an eyewear dock.
During the development of the Vanquish, Giro have greatly considered the science of aerodynamics. The helmet takes advantage of the Venturi effect to channel air across the head and exhaust warm stale air, and the four-piece polycarbonate hardbody shell interlocks in such a way that it creates a step-down. Giro claim this tricks the air into behaving as it would with a traditional teardrop TT-shaped helmet.
A tech-compatible aero helmet with great safety features and flexible ventilation
The Lazer Buller 2.0 is a helmet that will capture tech-lovers' imaginations with the array of features that are available, some of which are standard but others will come at a cost.
However, before we get into these features, it’s worth stating the Lazer Bullet 2.0 is, as a standalone helmet, a worthy inclusion in this list. It features a MIPS slip liner for added impact protection, an 'Airslide' closeable vent, a magnetic clip-on panoramic Zeiss lens, and internal channelling that uses the Venturi effect to help you keep a cool head. It also comes with a rear LED light and reflective stickers to increase visibility in low-light conditions.
If your helmet has been involved in an accident it can be replaced at a reduced price of approximately 50 per cent for up to three years after the purchase date, however, the dealer’s discretion will dictate the exact discount you receive. This is limited to select countries, however; the UK and Australia are not currently included.
The Bullet 2.0 is compatible with Lazer's integrated helmet tech, meaning for an added fee, you can add the Inclination Sensor and the LifeBeam heart-rate monitor.
A sleek-looking helmet with a comfortable retention system and a noise-reducing design
The Kask Utopia is the Italian brand’s aero-specific helmet. At the expense of a few grams and the frontal vents, the Utopia is claimed to save 'up to six watts than the most efficient rival helmet at 50km/h' which is 31mph. Bear in mind, the majority of other manufacturers make claims at 40km/h (25mph).
Kask haven't ignored ventilation though; the Utopia is said to be equally at home on climbs and in time trials. Using the Venturi effect, the way air is channelled through the internals of the helmet is claimed to improve both ventilation and aerodynamics.
The helmet is also designed to reduce wind noise around the ears, for a 'quiet ride experience', and features 5mm of moisture-wicking material called Resistex, which claims to take moisture away from the rider's head, moving it to the helmet's outer shell in order to improve comfort.
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