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.
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.
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.
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.
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 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.
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.