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Road Racing

The Clothesline clothing review: The Giro Aeon, a divine helmet, almost…

Nick Legan reviews the new Giro Aeon: Lighter than the Ionas, better ventilated than the Prolight. But it could use more sizes.

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The Clothesline review: Giro Aeon
Giro's newest helmet is the Aeon (pronounced A-on). Happily it came in VeloNews colors. Pardon the salt stains on the straps, but we take testing seriously here at VN.

The latest helmet from Giro was launched a couple weeks ago in Kortrijk, Belgium. Instead of rushing to press, I wanted to ride the helmet extensively before reviewing it. After many rides, one seven hours long and several other over three hours, I have to say that the Aeon disappears once you put it on. And that’s a really good thing.

The idea behind the Aeon was to bring the Ionos and Prolight helmets together in one package. The Ionos was a bit heavy compared to the latest light helmets and the Prolight wasn’t very well ventilated.

Giro, to its credit, says that the Aeon has better perceived ventilation than the Ionos. Only perceived because quantifying ventilation is very difficult. But I would have to agree, the Aeon keeps you cool.

To keep weight down, engineers scrutinized each part of the helmet. Instead of an internal skeleton like in the Ionos, Giro developed the SL Roll Cage. It’s a sort of exo-skeleton structure that helps minimizes the surface area of the foam touching the rider’s head. It creates more air space around the rider’s head, allowing more air to pass through the helmet.

Related reviews:

  • Specialized Prevail helmet
  • Catlike and Lazer helmets
  • Briko Mustang helmet

The SL Roll Cage is also 49 percent lighter than the In-Mold Composite Sub Frame in the Ionos. It’s so strong Giro can use a lighter weight EPS foam (15 percent less dense) which helps save weight.


The Aeon (pronounced A-on) is named after a type of divine entity. And while it’s hard to think of a bicycle helmet as divine, the Aeon is very light and fits most heads well. I may have been an exception though.

The Clothesline review: Giro Aeon
The Tri Loc adjusters are half the size of those found on the Ionos. The webbing is the same as used on Giro's Prolight.

Lazer helmets have been my preferred fit for years. For my size head, 56cm circumference, they fit well without looking like a head bucket. They may not be the lightest, but their Rollsys system has been great (and easily adjusted with one hand).

When I tried on a medium Aeon it was huge on me, I had to crank the Roc Loc almost all the way down. But I only barely fit into the small. I can’t comfortably fit a hat under the small. I understand the desire to keep the number of sizes to a minimum, but I think that adding a fourth size would really make for a better fit.

The Roc Loc 5 works really well and can be adjusted with one hand. Ben Delaney, our editor-In-chief, used a helmet-mounted camera on his Aeon and found tightening the Roc Loc to steady the shot over bumpy roads was easy.

The Tri-Loc under-ear adjustment is half the size of those on the Ionos helmet. The webbing is the same as the Prolight. This is done in the name of weight savings, but they also function exceptionally well.


At first glance, the Aeon reminded me of a mix of previous Giro helmets. Styling is consistent with Giro’s past: the rear spoiler and front fangs. The metal badging and a painted Giro logo on the side also look great. The large middle vent and split tail are the quickest way to identify the Aeon.

My biggest complaint is that you can’t securely stick most sunglasses in the helmet vents. This is a small gripe, but part of what I’ve liked about Giro helmets for years is that they carry shades will ease when I was climbing.


True to their word, the Giro Aeon is light, only 189 grams for the size small on the VN Scale. Claimed weight for a medium is 222 grams. The Roc Loc 5, the buckle and even the padding were all changed to help save weight. These parts combined to help save 36 percent over the parts involved in the Ionos. A new Slimline buckle is also on the way for 2012 production.

The Clothesline review: Giro Aeon
Tyler Farrar rode his Aeon for the first time at the Tour of Flanders.
Here’s how the Aeon stacks up with some other lids we’ve looked at recently:

  • Giro Prolight – 195 grams
  • Giro Aeon- 222 grams
  • Spec. Prevail – 230 grams
  • Lazer Helium – 265 grams
  • Giro Ionos – 309 grams

The Aeon is 8 grams lighter than a Prevail, 76 grams lighter than a Lazer Helium and boasts a whopping 87-gram savings over an Ionos. That’s pretty good for a helmet with full features and great ventilation.


At $250 the Aeon is expensive, but innovation doesn’t come cheap. Specialized’s latest helmet, the Prevail, is $20 cheaper and almost as light. The eight-gram difference may be worth it though if you buy into Specialized’s claims that the Prevail offers aerodynamic savings over other road helmets.

In the end I think most consumers will make their decision based on styling and fit. The Specialized fit me better, but I prefer the styling of the Giro. A tough call.

The Aeon will be available in May, so you don’t have to wait long to try one at your local shop.

Colors: Black, white, red/black, blue/black, matte titanium/silver

Special edition colors: Garmin silver/blue, Rabobank: Orange/Blue, Thor: Matte Black/World Champ stripes


Giro has clearly accomplished what it set out to do with the Aeon. It is significantly lighter than the Ionos and the ventilation is worlds better than the Prolight. For this reviewer, the fit wasn’t perfect but for those that it does suit, the Aeon may be divine after all.

An American in France

What’s it like to be an American cyclist living in France? Watch to get professional road cyclist Joe Dombrowski’s view.