The Giro Eclipse Spherical might be the new top dog in aero road helmets

We spotted some Canyon-SRAM and FDJ-Groupama riders wearing a new Giro road helmet back in March of last year, and now we know that it’s the California brand’s new Eclipse Spherical. 

Spin to win

As the name implies, the new model incorporates the MIPS Spherical two-layer construction that was first shown on the Giro Aether, where two completely separate foam liners — each with their own polycarbonate microshell — fit together in a ball-and-socket configuration. The idea here is that the double-layer design offers the rotational protection of more traditional MIPS systems, but with even freer and more consistent movement than other MIPS liners given the hemispherical interface.

Other safety-minded features include dual-density EPS foam to presumably better handle both low- and high-speed impacts than single-density liners, location-specific thicknesses for each of those densities to balance energy absorption and bulk, and reflective decals to provide some low-level visibility. The Roc Loc 5 Air retention system is also compatible with Giro’s Roc Loc 5 LED add-on rear-facing flasher.

Wondering how the Eclipse Spherical fares in Virginia Tech’s independent testing? So am I — the new helmet hasn’t yet been tested so we’ll unfortunately have to wait on that one.

It’s good to be small

We originally speculated that this was to be Giro’s next-generation aero road helmet, and at least based on the company’s claims, that’s certainly the case.

Giro says the Eclipse Spherical is its most aerodynamically efficient road helmet to date — and the most efficient road helmet it’s ever tested, period, even trouncing the performance of the more overtly speedy Vanquish MIPS that debuted in 2017. According to Giro, the Vanquish MIPS will save a rider traveling 40 km/h (25 mph) 103 seconds over 160 km (100 miles) as compared to the Aether, but the Eclipse will supposedly shave another minute on top of that, despite looking less aero and featuring a lot more vents. All of that testing was done using the company’s wind averaged drag metric and with the rider’s head in the typical riding position 80% of the time, and head-down for the rest.

How is that possible, you ask? According to Giro, much of the Eclipse Spherical’s aero advantage lies simply in its trimmer profile. After all, while it’s always possible to make something slice through the air more easily by tweaking the shape, it’s a lot easier to do that when you’re just punching a smaller hole in the air.

“To be honest, a big chunk of savings comes from reducing frontal area,” said Giro brand manager Peter Nicholson. “Through painstaking engineering, including using the Progressive Layering enabled by Spherical construction, judicious deployment of Nanobead EPS foam, and sifting through all the data generated through hundreds of impact tests in our DOME facility, we were able to make a smaller helmet that still meets or exceeds the certification standards.”

Looks can be deceiving

One obvious benefit of all of those vents is better airflow as compared to the Vanquish MIPS, which was good if you were moving along at a decent pace, but noticeably toasty otherwise. When tested with Giro’s Therminator instrumented headform, Giro says the cooling performance of the Eclipse Spherical is not only far better than the Vanquish — and even better than the Helios Spherical, for that matter — but very nearly as good as the non-aero Aether. 

Although the Eclipse’s outer shell and liner sport a fair amount of solid surface, the inner liner is far more open and there’s a lot of internal channeling built into the design. In other words, the Eclipse Spherical may not appear nearly as well ventilated as the Aether, but there’s an awful lot of room in between the rider’s head and the outer shell for incoming air to circulate around, and for hot air to radiate out.

Giro has also added the same tabbed browpad extension found on the Helios Spherical, which is designed to help redirect sweat away from the rider’s forehead. Once the pad is saturated, perspiration collects at the end of that tab instead of right against your skin, with the goal being that sweat drips down in front of your face instead of straight on to your sunglasses. Though I haven’t had a chance to sample this feature on this new Eclipse Spherical model, prior firsthand experience on the Helios Spherical (and various Bell helmets from which the concept is derived) has been more than positive. 

Pretty light, and lots of color choices

Given the focus on safety and that complicated dual-layer design, it’s no surprise that the Eclipse Spherical isn’t ultralight (it’s certainly a long ways off from the POC Ventral Lite, for example). That said, it’s pretty reasonable at 275 g (claimed) for a medium CPSC-approved sample, or 267 g (actual) for a medium CE-approved one. That puts it 30 g lighter than the Vanquish MIPS, 9 g lighter than the Helios Spherical, or 25 g heavier than the Aether — not bad, all things considered.

Giro is offering the Eclipse Spherical in three standard sizes and five colors (sorry, the team-edition colors are apparently team-only). Select Asian markets will also get their own fit variant that use a more rounded headform. 

Retail price is US$250 / AU$430 / £240 / €260, and helmets are supposedly available now. Interestingly, the Eclipse Spherical will be offered in addition to the aging Vanquish, not as a replacement for it.

“Vanquish isn’t going away, at least not any time soon,” Nicholson said. “People love the shield.”

That price makes the Eclipse Spherical a heck of a lot more expensive than the last helmet that Giro used the Eclipse model name on almost 15 years ago. However, it seems safe to say that this new version should also be a much better helmet in pretty much every way, and when you consider the claimed time savings relative to other options like wheels and frames, speed-focused riders should actually see some solid value here.

But how does it stack up again other Giro models, or other similar competition from other brands? We’ll find out soon enough; I’ve got a sample on hand, and just need Colorado to warm up so I can test this thing properly. Stay tuned.

More information can be found at www.giro.com.