Oakley ARO5 Helmet

Oakley's Mips-equipped ARO5 is a well-made aero road helmet with good ventilation and a Boa retention-system that dials in a comfortable fit. Be aware that it is a deep-fitting hat, though, and can interfere with glasses.

• Pros: Boa lace adjustment system is very easy to use to get a comfortable fit
• Cons: Deep-fitting – small-headed people especially, try before you buy

Out of the box, the ARO5 claims great safety with the Mips system (see below) and has decent aerodynamics plus big vents for keeping you cool. It's the helmet of choice for a lot of pro triathletes this season, and Team Dimension Data will be using the ARO5 and TT ARO7 version.

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The ARO5 sits in the middle of the range, with a lightweight polycarbonate shell and EPS protective foam. Oakley has incorporated Mips Brain protection technology into the helmet. This is being seen in a lot of helmets now, at all price ranges. It's a low-friction layer that, according to Mips, works by "absorbing and redirecting the energy and force generated during a crash that would otherwise be transmitted to the brain". It's clever technology and definitely something I like to see in helmets.

The helmet has big vents at the front which do a great job at keeping you cool. The X-Static brow pad is one piece and uses silver to inhibit the growth of bacteria and, apparently, eliminate odour. I didn't notice any nasty niffs in my weeks of testing. In the box you get a spare pad too. Padding in the rest of the helmet is minimal, with just a small pad for the top of the head.

Size & adjustment

Oakley has used a Boa FS1-1 system to dial in the fit of the helmet. It's a height-adjustable, 360-degree design using a lace that tightens all round the head and lies flat. The cradle can be adjusted up and down to get the right fit around the back of the head, then you can dial in the fit very easily, even with gloves on.

The straps around the chin are the nice lightweight sort that sit flat and you barely notice them.

As a small-headed person, I was reviewing a small, which should fit 52cm-56cm heads. Although I could get a comfortable fit, no matter how I positioned the helmet on my head and tightened it up, it wanted to sit too far forward for my liking. The Boa tension system worked really well, but I had to have it quite tight to try to get the helmet to sit well on my head. (It's not me in the photos.)

The issue I had was that the whole cradle and lace system sits very low, giving the helmet a deep fit. It fits fine if you don't mind it sitting low on your forehead, but it sat right on top of my glasses. The only way to get it to sit better was to have my ponytail threaded through the cradle, which is do-able if a little faffy, and not something I normally have to do with other helmets.

The ARO5 could be a very nice helmet, it's just not quite suited to my head. Other options you could consider are the Specialized's S-Works Women's Prevail II – a very lightweight helmet with some aero features – or the Lazer Cosmo, which fits better on my small head. It's the same price (well, 99p more) as the ARO5 now, and can be turned into an aero helmet by adding a shell.

> Should you buy an aero helmet?

The price could be a drawback for many, too. At £199.99 it is a top-end helmet, and if you want a more affordable road helmet without the aero features, there are numerous options – like the Bell Tempo Mips, for example, at £64.99.

If you like the look of the ARO5 but not the matt black, it's available in other colours.

Verdict

A deep-fitting Mips-equipped lid geared towards roadies with a need for speed