Oakley ARO5 helmet review: Feelin’ hot, hot, hot

by James Huang


It perhaps shouldn’t have caught anyone off-guard when Oakley introduced bicycle helmets last year at the Eurobike trade show. After all, the eyewear icon had already expanded into snow helmets in early 2016, and given its long-standing position in the cycling world, it seemed to be a natural progression.

Out of the three-model range, the ARO5 is Oakley’s aero road model, and it certainly looks the part with its sleek shape. However, its venting leaves much to be desired, and Oakley has yet to offer up any hard data to support its aero claims, so one has to wonder how much of a drag advantage it really has to offer over a more conventional lid.


Ticking the boxes

Oakley has an enviable reputation when it comes to pushing the limits of design, and the ARO5 is undoubtedly distinctive, even in a more subdued color than the high-vis “Retina Burn” version I tested here. As is typically the case with aero-minded road helmets, the pleasantly low-profile exterior fits closely to your head, and the neatly clipped and rounded tail is a far cry from the spiky designs from just a few years ago, which were seemingly inspired more by the hairstyles of Japanese anime characters than wind tunnel testing.

Aside from the somewhat ostentatious “O” logo on the side, the ARO5 is actually quite visually subdued. Oakley seems to be letting the shape of the ARO5 do most of the talking here, and I think it’s a good move. Overall, I’d say it’s a good-looking helmet.

The Oakley ARO5 fits pleasantly close to the head. It’s a comfortable lid, too, thanks in part to the cozy Boa-based retention system, the slimline webbing, and the well-placed fixed splitters.

Not surprisingly given the company’s background, Oakley has put a lot of emphasis on how the ARO5 fits with your eyewear. The Boa FS1-1 retention system uses a whisper-thin fabric cord instead of the hard plastic strips more often used on cycling helmets, and it doesn’t interfere at all with even the longest ear stems on the market; they simply fit right over the cord and grip the sides of your head as intended.

The outer two forward-facing vents are perfectly placed for stashing your sunglasses when you don’t feel like wearing them, too, and long cutouts in the interior leave plenty of room for the sunglass arms, instead of uncomfortably squashing them between the helmet liner and your noggin. Oakley absolutely nailed this aspect, no question.

Speaking of vents, Oakley has taken a dichotomous approach to keeping your head cool. Although the overall external shape of the ARO5 is very similar to the Giro Air Attack, the venting arrangement couldn’t be more different.

You can certainly feel air hitting the front half of your head at higher speeds when wearing the Oakley ARO5.

Giro opted for just six small slits in the Air Attack, but supplemented them with a series of very deep internal channels to help circulate air in between that helmet’s foam liner and your head. Oakley has instead basically cut open the entire front half of the ARO5, creating four (well, six if you factor in the plastic reinforcing ring that bisects the two main ports) gaping vents that leave most of the front of your head fully exposed to oncoming air.

Up top is a single intake port presumably meant to help funnel air toward the back of your head, but the rear half of the ARO5 is otherwise virtually solid, with just the smallest of perforations present at the tail.

On the safety front, Oakley has equipped the ARO5 (and all of its cycling helmets, actually) with a MIPS low-friction liner, which is claimed to reduce the incidence of closed-head injuries by lessening the severity of rotational forces during a crash. Coverage is fairly minimal out back with the high-cut rear profile, but on the plus side, the dearth of vents there leaves a lot of foam on hand to help dissipate impact energy.

The retention system’s textile cord is entirely unnoticeable against your head, and doesn’t interfere at all with sunglass arms, at least on my small-to-medium-sized head.

Oakley offers the ARO5 in three sizes — all of which use a rather ovoid shape and seem to run smaller than usual — and seven color options. Retail price is US$250 / AU$300 / £200 / €250. Actual weight for a medium CPSC-approved US sample is 322g.

Missing the mark

The primary motivation for anyone interested in an aero road helmet is, of course, aerodynamic performance. But in this key area, it’s not entirely clear how aero the ARO5 truly is. Although the ARO5 looks the part to the untrained eye, a statement from Oakley only offers vague reassurances of the ARO5’s speediness.

“[The ARO5 is] verified to be among the fastest road helmets on the market via 31 iterations of extensive CFD testing vs. top competitors, wind tunnel testing, and professional athlete input and testing (mainly by Team Dimension Data).”

Even if you take Oakley’s aero claims at face value, the ARO5 has some other major downsides.

With no meaningful venting on the entire rear of the helmet, the Oakley ARO5 is truly stifling unless you’re traveling at a healthy speed.

Ventilation is always a compromise when it comes to aero road helmets, and few expect them to perform as well in that respect as a conventional lid with more openings. The ones that are good at funneling air across your head at higher speeds oftentimes feel hot on slower climbs, and the ones that do a better job of keeping your head cool at both high and low speeds don’t always perform that well in the wind tunnel. But even in that context, the ARO5 falls seriously short of the competition.

High-speed cooling ability is pretty good, and you can feel the air hitting much of the front half of your head at higher speeds. But there’s very little internal channeling on the ARO5, and what few of them there are are too shallow and serpentine to be meaningful. Air can come in, but a lot of vent area feels wasted since there’s no clear outbound flow. On other helmets with more effective internal shaping — such as the Giro Vanquish, Bontrager Ballista, and POC Ventral — there’s a veritable torrent of air cascading across the entire top (and sometimes, sides) of your head for far more effective cooling at cruising speeds.

It’s a similar situation with bugs. Anything that gets sucked into the forward ports has no choice but to keep bouncing around in there until you completely pull the helmet off your head. It’s like a reincarnation of the old Roach Motel advertisements in bike helmet form: bugs check in, but they can’t check out.

The upper intake port seems like it should help keep the top and back of your head cool, but a lack of proper internal channeling means the incoming air doesn’t have anywhere to go.

At slower speeds, the ARO5 is truly stifling. With no significant vents at all on the rear half of the helmet, heat has nowhere to escape when you’re laboring uphill. It turns out the internal channeling that is so effective on other aero road helmets at higher speeds is still beneficial at lower ones. Some models, like the Bontrager Ballista and Giro Synthe, also add perforated vent covers that effectively behave as if they’re solid at faster speeds while still letting you literally blow off some steam at slower ones. Unfortunately, the ARO5 benefits from none of these features.

Making matters far worse is the ARO5’s old-school browpad design. There’s almost no air space between the pad and foam liner, and even if there was some, the back of the pad is completely covered by the solid plastic MIPS liner so there’s zero chance sweat can evaporate. I set out one day on a pleasant spring morning with low humidity and temperatures hovering around just 16°C (61°F), with a plan to head up a local 7% climb that was well shaded. But despite the sub-threshold effort, there was so much sweat pouring out of the ARO5’s browpad that I felt more like Floyd Landis in Stage 17 of the 2006 Tour de France, dumping bottle after bottle on my head.

Add in some legitimate heat and humidity, or just a harder effort, and donning the ARO5 at anything other than higher speeds (say, 35km/h or more) makes you feel like a marshmallow at the wrong end of the roasting stick. It’s a good thing Oakley nailed the sunglass storage aspect of the ARO5, because you’ll need to keep them there a lot. But the worst part of the ARO5’s stifling feel was the fact that nearly every time I wore it, I had that awful Buster Poindexter song from the 1980s going through my head on endless loop.

Not surprisingly, Oakley has absolutely nailed the sunglass storage aspect of the ARO5 helmet. It’s easy to stash eyewear up there (provided they have straight earstems), and they hold on tight, too.

The ARO5 is otherwise quite comfortable. There’s a minimal amount of padding on the inside, but the smooth MIPS plastic liner seems to help make up for that. The thin webbing also sits nicely on the side of your face, and the fixed splitters leave plenty of room around your ears. Three height settings on the retention system make it easy to find the sweet spot, too.

You’d best exercise some care when the ARO5 isn’t on your head, however. The lower edge of the EPS foam liner is totally exposed, and there’s also a lot of uncovered foam up top as well. The two bare foam edges at the top of the two main forward-facing vents are particularly worrisome, and even after a few weeks of regular testing, my ARO5 sample is showing more scars than I’d prefer.

A decent first effort, but lots of room for improvement

Overall, Oakley has made a fair first stab at the aero road helmet segment, but given the premium pricing, the performance that it delivers on the road doesn’t make the ARO5 a particularly compelling option. Several other aero road helmets (like the Bontrager Ballista, POC Ventral, Specialized Evade II, and Giro Vanquish) manage to offer proven aerodynamic advantages while still doing a much better job of delivering reasonably balanced ventilation performance, too.

I’ll freely admit to being a fan of Oakley’s sunglasses; rarely has the company put out something that I didn’t feel was functionally superb (or often superior to the competitors), even if the styling wasn’t always to my liking. There will undoubtedly be plenty of Oakley devotees who will be willing to overlook the ARO5’s flaws to stay true to the brand, and the company’s first stab at an aero road helmet may suit you just fine if you’re only ever going to be moving quickly while wearing it.

But overall, even the most diehard of supporters won’t be able to deny that there are better options out there.

Visit oakley.com for more information.

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