Giro Releases Ultralight 189 Gram Aeon Bicycle Helmet

ultra lightweight giro aeon 189 gram bicycle helmet

Giro has just upped the ante something fierce among the lightweight lids war. Their new 189g Aeon helmet makes their Prolight look downright tubby, and gives the new Specialized Prevail supermodel envy. Want specs? Yeah, you know you do…jump on past the break for all the goods…

Update: Actual weight after the break!

We know the comments are coming, so let’s just state for the record: If you haven’t ever worn an insanely lightweight helmet, don’t bag it. They have to pass the same CEN and CPSC testing to hit retail shelves as the heavier ones, and chopping five ounces or more of bouncing, neck straining weight during a multi-hour ride is the difference between upper back pain and not. Trust us.

The Giro Aeon gets its feathery lightness by using a “Thermoformed SL Roll Cage” that Giro says is halt the weight of their previous composite internal skeleton. This internal framing reinforces the structure and helps keep it together in the event of an impact, and it allows them to use less EPS foam. Speaking of the foam, they used a less dense EPS material on the Aeon,.

They also opened up the wind-tunnel-tested vents quite a bit…all 24 of them! This puts fewer points of the helmet in contact with your noggin, which are cushioned by X-Static padding and held in place with Slimline webbing. Adjustment comes from their excellent new RocLoc5 dial.

Three sizes and eight colors will be available, and we’ll post more images as soon as we have them.

Technically a road helmet, we’re absolutely going to rock this thing on the dirt when it comes in for review (it is coming in, right Mark?) and give it a thorough run through.


Last week, I (Zach) had the opportunity to check out the Aeon first hand before it was released to the world. While I didn’t have my camera (obviously, due to the poor cell phone shot), I did have my handy Park gram scale. If you notice, the tag in the helmet read 222g for a medium, which is incredible due to the fact that it retains Roc Loc 5.

Sorry for the horrible picture. Thankfully, I had my cell phone camera.

After weighing it on the Park scale, it came in at 225g, only 3 more than claimed, which is completely reasonable. It wasn’t until this weekend while I was watching the Tour of Flanders, that I noticed that Giro was claiming the Aeon was 190g. Curious about the discrepancy, I asked Giro what the deal was and their response was, “That’s the weight of CE certified version for EU. US version is 222 avg. for CPSC certification.”

So there you have it, 190g for the Euro CE certified version, and 222g for the US CPSC certified version (about). That means that for the US market, the Giro Prolight is still Giro’s lightest helmet, however the addition of improved comfort and adjustability of the Roc Loc 5 system will be sure to make it a tough decision between the two.

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11 years ago

Seems like a lot of pros have been moving back to the Ionos over the Prolight anyway. Light helmets seem irrelevant.

11 years ago

I love my Prolight, might not look as cool as other helmets but it is VERY comfy.

11 years ago

190 g is for the small; I read it somewhere. I will look for it.
Still, my head can’t tell whether a helmet weighs 50-100 g less, but
it sure can tell which has better ventilation.

11 years ago

190 g claim for small on (I hope it was ok to mention another bike website).

Zach Overholt
Zach Overholt(@zachoverholt)
11 years ago

Yes, 190 for the small CE-Approved (Euro) Helmet. From BikeRadar: “Our CE-certified small sample weighs just 190g, making it just less than 30g heavier than an equivalent Prolight (but still about 100g lighter than an Ionos) while CPSC versions will tack on only another 30g or so.” So exactly what was stated, and around 222 for the CPSC (US) Version.

6 years ago

I guess almost all of your readers are serial (and serious) bikers, but I just want to know how it looks on a head. With some competitive choices, I am buying on the looks.