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Giro Helios Spherical helmet



Incredibly comfortable performance lid with well-integrated MIPS – now available at a more reasonable price
Well-integrated MIPS
Comfortable fit
Audible clicks to adjust
Low profile
No eyewear grips
You can get lighter for the money
Contact: Recommends

This product has been selected to feature in recommends. That means it's not just scored well, but we think it stands out as special. Go to recommends

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

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The Giro Helios Spherical helmet benefits from the trickling down of the company's highly praised MIPS Spherical technology – which was first introduced on its top-end Aether – to this less race-focused lid. The protection of the MIPS (Multi-directional Impact Protection System) comes on a comfortable lid with ample adjustability, at a cheaper price.

The Spherical technology powered by MIPS included in the Helios uses two separate foam liners and 'elastomeric anchors' in a ball and socket construction, with the outer one rotating around the inner, in the event of a crash. These shells absorb the harmful rotational forces to provide greater impact protection (read our full article, linked below, on MIPS to further understand these benefits).

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The exterior polycarbonate shell of the Helios Spherical is in-molded, which means that it is permanently fused with the EPS foam liner for increased durability.

The Spherical technology integrates the slip plane into the helmet shell itself – it appears as though the main body of the helmet has been split equally in half and then reattached with tightly strung rubber bands. By gently holding the helmet you can shift these two layers with just your hands – the movement isn't only apparent in a collision.

2021 Giro Helios Spherical Helmet - inside.jpg

Giro says this technology eliminates the side-effects of using a plastic insert, which can be found in other conventional MIPS systems. With the Spherical lid, ventilation and sweat management has been improved, and the 'snag points' that can pull hair are non-existent. By using two separate foam liners, Giro says the density of each of these layers has also been optimised to address the differences between high- and low-speed impacts.

> All you need to know about MIPS

Tightened up, this lid provides a comfortable and secure hold, with a fit that can be adjusted with ease thanks to Giro's Roc Loc 5 Air system. To spread the pressure and to cater for varying head shapes, the system stretches the full circumference of the helmet. It's controlled by a wheel at the rear, which makes a reassuring audible click on each slight twist for accurate fine-tuning, both when tightening and clicking back down to loosen slightly.

2021 Giro Helios Spherical Helmet - tension system.jpg

Then there's the vertical fit tab which has the option of four positions for 35mm of up-and-down adjustment and meant I was able to accommodate my hair tied back at the height I prefer (it's not me in the photos!).

2021 Giro Helios Spherical Helmet - worn back.jpg

The fit was sturdy, even when detouring off the beaten track onto rougher terrain – it is suitable as a gravel lid.

2021 Giro Helios Spherical  cycling helmet - worn side

Cushioning the forehead is a single interior pad which curves round the front end of the helmet. Even though the soft padding is thicker than most performance helmets, it sits flush and is incredibly comfy to wear. Moisture is also effectively prevented from dripping down into your eyes, and the pad's anti-microbial qualities have staved off any unpleasant workout odours. That said, it's not like I have been getting particularly sweaty in these current sub-10°C conditions – even when in the hurt-cave doing intervals. So, more on the performance of this sweat collector when summer hits...

2021 Giro Helios Spherical Helmet - worn front.jpg

Cooling is managed through 15 vents. Other than the larger central vent, the spattering of escapes are quite small. Given the size and restrictive shape of the vents on the Helios it is quite surprising that Giro says its cooling efficiency rating is only slightly behind that of the Aether, by ~2%. Deep in winter at the moment (again, sorry), it's going to be a little while until I can fully comment on the ventilation promises of the Helios Spherical in the heat. That said, the lid has felt airy as I can feel the wind blowing through my hair.

2021 Giro Helios Spherical Helmet - top_.jpg

Helmets with a MIPS system do make weight sacrifices for the safety gains. The medium sized helmet on test weighs in at 274g and doesn't feel feathery (perhaps I am slightly biased because my day-to-day helmet is the Kask Valegro at ~200g), but the Helios is respectably lightweight for a MIPS helmet.

2021 Giro Helios Spherical Helmet - worn.jpg

Unlike the Aether, there are no gripper pads in the forward vents to keep your sunglasses stashed in place, which is a shame.

Forty pounds cheaper than the Aether, at £229 the Helios is an enticing option with its safety benefits of MIPS delivered on a performance lid. MIPS systems can be found on helmets for as little as £64.99 with Smith's Signal MIPS helmet, but this is aimed at more casual use.

Back to performance lids, the MET Rivale MIPS is cheaper at £140, and impressed with its great adjustability and stunning looks – added to which, it's 38g lighter. With effective ventilation and an innovative closure system, the Lazer Z1 MIPS also costs less at £169.99. But the MIPS systems on both of these feature the less-well-integrated yellow plastic insert.

> Buyer’s Guide: 19 of the best lightweight high-performance cycling helmets

Three sizes of the Helios Spherical are available, fitting head diameters from 51cm up to 63cm. The 55-59cm medium I had on test came in the loudest option with the red on the inner shell blaring through the black and white outer. There other four colourways in the range, including a total stealth black, a warmer matt black, black with yellow highlights, and white with silver fade.

2021 Giro Helios Spherical Helmet - side 2.jpg

Overall, with its understated looks, the Helios Spherical impressed as an incredibly comfortable lid with a low-profile design that still delivers well on aero and cooling performance. Although still not cheap at £229, Giro brings its innovative and well-integrated Spherical MIPS technology to a more affordable lid, and leading brain protection technology now doesn't come with compromises. It's comfortable, well ventilated and lightweight enough.


Incredibly comfortable performance lid with well-integrated MIPS – now available at a more reasonable price test report

Make and model: Giro Helios Spherical helmet

Size tested: Medium

Tell us what the product is for and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?

Giro says: 'The heart of the Helios' extraordinary design and performance is Spherical Technology, which utilizes a ball-and-socket design powered by MIPS®, the market-leading brain protection system that can help to reduce rotational forces. Spherical Technology allows the helmet's outer liner to rotate around the inner liner during a crash, and also allows Progressive Layering of the inner and outer liners to provide more comprehensive protection and performance. In addition to advanced head protection, the Helios' 15 Wind Tunnel vents provide exceptional cooling power that's enhanced by our patented Roc Loc 5 Air fit system and plush, antimicrobial Ionic+ padding for exceptional sweat absorption. It's the ideal match for your road and gravel adventures."

Tell us some more about the technical aspects of the product?

Giro lists:

Spherical Technology™

MIPS® brain protection system Progressive Layering Nanobead EPS

Ionic+™ anti-microbial padding

Reflective decals


Independent, In-Mold liners with spherical ball-and-socket design

Full lower Hardbody coverage


Roc Loc® 5 Air


15 Wind Tunnel™ vents and deep internal channeling

Rate the product for quality of construction:
Rate the product for performance:
Rate the product for durability:
Rate the product for weight (if applicable)

There are many lighter helmets out there, but this is quite light for one with MIPS.

Rate the product for comfort (if applicable)
Rate the product for value:

Tell us how the product performed overall when used for its designed purpose

Very well. A comfy and secure lid. We don't impact test helmets on the basis that that has already been done in order for them to receive their safety certificate.

Tell us what you particularly liked about the product

Well integrated MIPS, and the front padding.

Tell us what you particularly disliked about the product

No eyewear grips, and the price.

How does the price compare to that of similar products in the market, including ones recently tested on

Forty pounds cheaper than the Aether, which features the same Spherical Technology, but considerably more expensive than other performance MIPS lid including the MET Rivale MIPS (£140) and Lazer Z1 MIPS (£169.99). That said, the MIPS systems on these helmets is less well integrated.

Did you enjoy using the product? Yes

Would you consider buying the product? Yes, but in one of the subtler colourways.

Would you recommend the product to a friend? Yes

Use this box to explain your overall score

I'm really impressed with the integrated MIPS system, which raises this smart-looking helmet from very good to exceptional, and a 9, despite the still-high cost. It's incredibly comfy to wear and comes with great adjustability, though I would have liked to see eyewear grips included.

Overall rating: 9/10

About the tester

Age: 23  Height: 177cm  Weight: 63kg

I usually ride: Road bike  My best bike is:

I've been riding for: 10-20 years  I ride: Every day  I would class myself as: Expert

I regularly do the following types of riding: road racing, cyclo cross, commuting, touring, club rides, sportives, general fitness riding, Gravel riding, indoor turbo and rollers, track

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