Giro Eclipse Spherical helmet review: Free speed without the usual drawbacks

The Eclipse Spherical is supposedly the most aero helmet Giro has ever made, but it’s also good at being an everyday lid – even in the heat.

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Cycling gear purpose-built for efficient aerodynamics is typically saddled with compromises, with that supposedly “free” speed often coming at the expense of other desirable attributes. When it comes to helmets, that usually means more weight and less ventilation. However, Giro’s latest Eclipse Spherical manages to slip cleanly through the air while still being surprisingly cool, comfortable, and reasonably lightweight — and it also incorporates the company’s latest safety tech and looks good in the process, too.

Getting to know the Eclipse Spherical

I’ve already covered the salient features of the Eclipse Spherical helmet in depth when it was announced back in March, and you can read all the details here. For those of you who are more interested in the CliffsNotes, however, here’s a recap. 

The Eclipse Spherical is the successor to the Vanquish, a dedicated aero road helmet that Giro introduced back in 2017. Not surprisingly, Giro says the Eclipse Spherical is more aerodynamic than the Vanquish, to the tune of a full minute of savings when traveling at 40 km/h (25 mph). What is surprising, though, is how Giro supposedly got there. 

The Giro Eclipse Spherical helmet is supposedly a lot more aerodynamic than the Vanquish, but perhaps more importantly, it’s also more usable in a wider range of conditions.

The Eclipse Spherical doesn’t resort to any sort of wacky shapes, instead relying heavily on a simple principle to reduce drag. According to Giro brand manager Peter Nicholson, the Eclipse Spherical’s substantially downsized frontal area gives it an inherent aerodynamic advantage over the more bulbous Vanquish, and while there was still plenty of tuning required from there, the smaller profile made that a lot easier. 

That smaller profile was made possible due to the helmet’s dual-layered construction. As the name implies, the Eclipse Spherical incorporates Giro’s latest MIPS Spherical architecture, which is essentially one helmet nested inside another with a spherically shaped, low-friction interface between them. First introduced on the Giro Aether, MIPS Spherical retains the rotational slip-plane that’s core to the MIPS concept of brain protection, but supposedly improves on it given the now-perfectly spherical interface.

The use of different foam densities allows for that more compact profile mentioned above, and moving that slip-plane away from the rider’s scalp carries the additional benefit of removing a lot of the usual MIPS hardware that could occasionally snag your hair. And if you happened to love the Vanquish’s optional magnetic visor? Sorry, it’s just traditional sunglasses for the Eclipse Spherical.

The MIPS Spherical construction essentially produces two helmets nested one within the other, with a low-friction spherical interface between the two that provides the rotational slip plane MIPS says is key to reducing the incidence of traumatic brain injuries.

Giro offers the Eclipse Spherical in three standard sizes and five colors, plus a more rounded version for select Asian markets. Actual weight of my CPSC-approved medium sample is 274 g, and retail price is US$250 / AU$430 / £240 / €260.

Eclipsing the Vanquish

I spent plenty of time in the Vanquish, and was generally happy with it overall, with one exception. As is the case with a lot of aero road helmets, ventilation performance was pretty good at higher speeds, and while it wasn’t bad at lower speeds either, there was plenty of room for improvement there.

Thankfully, the Eclipse Spherical is much better in that regard, which makes sense when you look at it. There is also more open vent area in general — up front, out back, and along the sides — and whereas the Vanquish was tuned primarily for flow-through ventilation, the Eclipse Spherical’s vents are positioned to better allow heat to passively escape, even when it isn’t being actively pushed out from the front.

There are more vents than there were on the Vanquish, and they’re arranged such that you don’t have to be moving quickly for air to pass through the interior.

Nowhere was this more obvious to me than during a recent trip to Nice, France, where I climbed the Col de La Madone in intense midday August sun with temperatures cresting 30°C (85°F), high humidity, and barely a breeze to speak of. Although my body was overheating a bit in general, my head stayed surprisingly comfortable. Even better, the Eclipse Spherical also manages sweat well with that little tabbed extension on the browpad doing an excellent job of diverting drips to out in front of your sunglasses instead of straight down on to the lenses. 

Need more high points? It’s easy to stash eyewear in the lower forward vents, the relatively generous interior padding is comfortable even on shaved heads, the full-wrap polycarbonate shell keeps everyday dings and dents at bay, and as I often find with aero road helmets, it’s pretty quiet (or at least less noisy) at high speeds than non-aero models, too. 

I found myself comparing the Eclipse Spherical to Specialized’s new Evade 3, and at least in my opinion, it was no contest. The Giro was not only much better ventilated — at high and low speeds — but also substantially lighter with a lower-profile shape and more built-in safety tech, all at a lower price to boot.

Beauty is in the eye of the beholder, but at least to my eye, the Giro Eclipse Spherical is a good-looking lid.

Surely there are some downsides, no? 

Well, as impressive as the ventilation is on the Eclipse Spherical, it’s still not as airy as something like the Aether (or especially the new Specialized S-Works Prevail 3). And although Giro certainly implies the MIPS Spherical technology makes for a safer helmet, that’s far from a foregone conclusion. Virginia Tech unfortunately hasn’t yet published test results for the Eclipse Spherical, but the Giro Aether Spherical (which also features a MIPS Spherical design) only does marginally better than the Synthe MIPS predecessor on which it’s based.

Price-wise, US$250 / AU$430 / £240 / €260 certainly isn’t anything to sneeze at, but even then, that’s still less expensive than most of the competition. 

Otherwise, I honestly really don’t have many holes to poke in this one. Well done, Giro. This one’s a winner.

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