Bell Star Pro helmet

The Star Pro is Bell's brand new aero helmet and what sets it apart from most aero helmets is a slider that opens and closes the side and top vents. With the vents closed, Bell reckon the Star Pro is faster than the fastest aero helmets currently available, while with the vents open, they claim ventilation as good as any regular helmet.

Aero performance

For this new helmet Bell developed what it calls Active-Aero Technology. Quite simply, there's a plastic slider at the back of the helmet that can move an internal liner to open or close the top and side vents. The rear vents remain open at all times.

When you want maximum aerodynamics you close the vents, when you need some refreshing air over your scalp, simply open them up. It's a simple concept, and well executed. The Kask Infinity has a similar sliding vent but that's at the front.

The slider functions well, and is easy to do on the move WITH just one hand. It doesn't have the premium feel you'd expect of a helmet costing £200 in its most expensive incarnation however, instead it feels a bit cheap and plasticky. I'd expect better at this price.

In its own testing at the Faster wind tunnel in Arizona, USA, Bell reckons the Star Pro with vents closed is faster than any of its competitors such as the Giro Air Attack and Specialized Evade. With the vents open, the company claims it's as effective at keeping your head cool as a traditional road helmet.

"A full range of competing aero helmets were tested at the Faster wind tunnel facility [in Scottsdale, Arizona, USA] utilising the industry-adopted wind-averaged drag (WAD), a wind velocity of 25mph (40kph), and a 30° head angle for all helmets," says Bell. "Tests proved that the Star Pro, with vents closed, is the fastest helmet on the market when compared to other very well-known aero competitors."

These are impressive claims. They're also claims that, along with most aero products, are impossible to verify without access to a wind tunnel. One day the industry might develop a standardised testing protocol for aero products but until that day happens, you can only take the company's claims at face value.

I did attempt to gather some comparative data against several regular vented helmets using a PowerTap to monitor the power requirements at different speeds, but wasn't able to get any meaningful results, which demonstrates how marginal the gains are with such a product.

If you want even more aero, the Star Pro can be bought with an optional visor (£30) that clips into place with a magnet, offering an extra aero advantage to those seeking every performance gain they can spend their money on.

I ditched it after one ride; it might be fine for racing but I didn't half feel a tit on a spin around the lanes. Let's just remember that this helmet has been designed for racing; it was developed in partnership with the Belkin team, so it's really aimed at those wanting the highest performance product.

A bit hot in here

What the Star Pro helmet does prove is that providing an aero helmet with adequate ventilation is a tricky compromise, despite Bell's best efforts to offer the best of both worlds.

There are vents underneath the front of the helmet, dubbed 'Overbrow Ventilation' which in combination with the side and top vents when the slider is open, does provide reasonablE cooling. It's nothing like the ventilation a Specialized Prevail or POC Octal provides though, but it's not bad. Even during this unseasonably warm weather, I never experienced an uncomfortable increase in temperature when riding around with the vents open.

With the vents closed, and if you're racing you'll be wanting to make the most of the aero benefits, it's another story. Those small 'Overbrow' vents simply don't provide enough airflow and my sweat rate increased massively, and it has nowhere to go but all over your face.

Even before half distance on a brisk one hour ride the other day, I was dealing with such an excessive amount of sweat pouring down from my brow into my face that I was ready to just ditch the helmet right there. There's simply inadequate venting that on a remotely warm day, you're going to struggle to prevent the extreme buildup of sweat.

You can partially combat this by leaving the vents open all of the time, but then you're compromising the aerodynamics, and thus defeating the point of buying an aero road helmet. Once you've reached the point of becoming a sweaty mess, opening the vents is too little too late.

Good fit and comfort

What of the rest of the helmet? Well it's a comfortable place to put your head for a ride, with the size medium fitting my head very well. There's a good range of adjustment and the retention system, though sitting a little high, is easy to operate and clasps the head with just the right degree of pressure. There is a good smattering of soft pads inside as well.

The helmet is constructed from a two-layer EPS, with lower density foam in the interior and high density EPS foam for the outer layer. The Star Pro will be available in three sizes and is CPSC and CE EN1078 certified, and there is a choice of six colours.

Conclusion

I was ready to love the Star Pro helmet. As it is, wearing it in warm to hot temperatures is just asking to become a horrible sweaty mess. Given most people looking to buy an aero helmet are probably racers, and most races are in the summer, that does limit its usefulness quite a bit.

It just goes to show you can't have an aero helmet without sacrificing decent ventilation. The rising popularity of aero helmets does show that this is a compromise many are happy to make, but for most people the potential gains are so small that you're probably better off sticking with a well ventilated helmet.

Verdict

Comfortable aero helmet with adjustable air vents attempts to offer best of both worlds, but ventilation is lacking