Specialized S-Works Prevail II Vent helmet review: So much air

by James Huang

photography by James Huang


The Specialized S-Works Prevail II helmet is already one of my favorite all-around road helmets. It’s lightweight, it’s exceptionally well ventilated, it fits well, it’s modestly aero, it looks good, and it’s even packed with MIPS SL pads and Specialized’s fancy ANGi crash sensor that works with a companion app to call for help if you crash and can’t call yourself. 

But if you already have a Prevail II and have ever felt like you needed even more airflow, Specialized has got you covered with the new S-Works Prevail II Vent helmet. It’s not massively different from the standard Prevail II, but it’s different enough, and in the right situation, that’s all some people will care about.

A nip here, a tuck there

If you hold the standard Prevail II next to this Prevail II Vent, there are far more similarities than differences. The shape and styling are so close to each other that most would struggle to distinguish between the two at first glance — and in fact, they appear to use the same polycarbonate microshell pieces. My small-sized CPSC-approved Prevail II Vent sample weighs just 252 g, which is exactly the same weight as the regular Prevail II. 

When you compare the standard Prevail II to the Vent variant, the differences become somewhat more obvious – as well as how similar the two helmets are, too.

Both helmets also use dual-density EPS foam liners, the same Mindset HairPort II height-adjustable retention system, the same thin-line straps with fixed splitters, the same MIPS SL padding. Both have five-star crash ratings from the lab at Virginia Tech.

At US$250 / AU$400 / £240 / €320, the retail price is the same too, but while the Prevail II Vent is also offered in three sizes, there aren’t quite as many color options.

So what’s the big deal? 

If you look closer, you can see that Specialized has replaced seven of the Prevail II’s foam bridges with “robotically spun aramid ropes” that essentially turn 10 big vents into three absolutely monstrous ones. And because of how they’re arranged lengthwise across the top of the helmet, the idea here is that the airflow is even less restricted than it was before. 

Where there were once small “bridges” of EPS foam, there are now small “ropes” of aramid fiber.

Put into numbers, Specialized claims the S-Works Prevail II Vent has a “20% increase in vented areas” relative to the standard S-Works Prevail II (although I’m guessing that figure applies only when you consider the altered vent networks, not the helmet as a whole), and it also “moves air across your head 18% faster than the original Prevail II.”

In more straightforward terms, your head will supposedly feel cooler in this helmet than the standard Prevail II. Duh.

Ok, fine, it works better (I think)

Specialized sent my test sample of the S-Works Prevail II Vent a few weeks ago, and while the timing conveniently coincided with a pretty substantial warm-up here in Colorado, it’s still only early March and a far cry from true summertime weather. As a result, I can’t say with 100% certainty that this new helmet keeps my head cooler on a slow, sloggy climb when it’s brutally hot and sunny than the regular version. 

That said, even when I’ve swapped back and forth on more modestly warm days, it does genuinely feel like there’s more air passing through the Vent variant — which isn’t at all surprising given those newly unobstructed pathways. I wouldn’t characterize it as a dramatic difference, but I suppose when you’re bordering on heat exhaustion and still have 100 metres to go to the summit, every little bit helps. 

The airflow through the newly opened-up sections is as good as it looks like it would be.

Otherwise, it’s pretty much business as usual here. Just as with the standard S-Works Prevail II, the Prevail II Vent is super comfortable to wear (although the more pronounced oval shape invariably won’t be as universally accommodating as ones that are more medium-oval), it’s noticeably lightweight, and I appreciate that the outer profile is quite trim while still offering good coverage around the back. 

The fixed strap-splitters also work well for me (although I know they don’t for everyone), and the little tabbed extensions on either end of the browpad do an admirable job of keeping sweat from pouring straight down the front of your face. Kudos, too, for how the straps are anchored in the lower edge of the helmet so they never get tangled up in the retention system, how the retention system works well with most eyewear I tried, and that the lower edge of the helmet is still mostly protected by the microshell so it doesn’t get too beat-up in day-to-day use.

As for that little ANGi crash sensor, well, I’m sorry to say that I didn’t auger my head into the ground to test it out for real. That said, I always find stuff like this to be more than a little finicky. It connects readily enough with the companion app (which is required for this to do its thing, of course), but I also have to remember to have the app running in the background — which I often don’t. Regardless, this little widget certainly doesn’t hurt anything, and if you’re after every bit of safety tech, it might provide some additional peace of mind so it’s hard to criticize it too much. If it really bugs you, you can always just pull it off. Take it or leave it.

Included with the helmet is Specialized’s ANGi crash sensor, which works with a smartphone app to call for help if you’ve hit the deck and are unable to do so yourself.

For the performance-minded, Specialized didn’t provide any aero data on the S-Works Prevail II Vent helmet, particularly not in comparison with the regular version, which is supposedly pretty efficient as far as fully vented helmets go. It doesn’t seem like this one would be all that different, but that’s just me guessing — and truth be told, if you’re really concerned about maximal aero gains, this probably isn’t the helmet you’re reaching for, anyway.

Lots of overlap

Taken all together, basically what you have here is everything that was already good about the standard Specialized S-Works Prevail II helmet, but with even better ventilation and seemingly no downsides whatsoever. I believe in cliché parlance, that’s called a win-win.

The profile looks admirably trim but the new S-Works Prevail II Vent still manages to earn Virginia Tech’s coveted five-star crash rating.

I can’t help but wonder now, however: given how similar the two helmets are to each other, why bother having a separate “Vent” variant at all? Why not just improve the ventilation of the existing design and keep it as the S-Works Prevail … III? 

Well, after the recent release of the S-Works Vent road shoes, my guess is that it comes down to marketing, and that Specialized will continue to expand on the “Vent” family with similarly themed items. Clothing seems obvious here, along with … who knows. 

“Prevail is the choice for riders when they are looking for an extremely well-ventilated helmet,” explained Specialized global road marketing operations manager Kelly Henningsen. “Prevail II Vent is just taking that a step further and a step cooler, so we are confident that the added ventilation is a huge plus in comparison of the two.”

Got it? Good.

Either way, this new S-Works Prevail II Vent helmet is superb – expensive, but superb nonetheless – and well in keeping with other top-end competition in terms of price. 

If you can think of a better option in this category, I’m all ears.

For more information, visit www.specialized.com.

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