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Giro Aries Spherical Helmet review

Lightweight premium road lid

Our rating 
4.0 out of 5 star rating 4.0
GBP £290.00 RRP | USD $300.00 | EUR €320.00 | AUD $500.00
Giro Aries Spherical Helmet

Our review

A supremely comfortable helmet with reassuring safety features, but the price may be prohibitive
Pros: Brilliant cooling, clever pads; exceptional comfort; highly rated safety
Cons: Strap ends unfinished; expensive
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The Aries is Giro’s latest helmet to include its Spherical system, a unique ball-and-socket design made using MIPS technology.

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MIPS (Multi-directional Impact Protection) is a safety feature incorporated into many of the best road bike helmets. It’s designed to reduce the transfer of rotational motion onto your brain in the event of a crash.

As well as being built around the Spherical technology, the Aries is one of the most comfortable road helmets on the market, light in weight and extensively vented.

That adds up to quite a compelling argument, but does it justify the lofty price tag of nearly £300?

Giro Aries Spherical Helmet spec and performance

Giro adopts the MIPS ‘slip-plane’ idea. However, instead of making a thin liner that sits between the helmet and pads, or anchoring the pads to elastomers that allow movement, Giro uses two EPS (expanded polystyrene) shells, one inside the other.

The elastomer anchors that link them are ball-ended and sit in a socket on the lower shell, enabling 360-degree movement. The outer shell is higher-density EPS foam to handle the initial impact, then the inner layer is lower-density to cushion and absorb energy before it reaches your head.

This system clearly works, because the Aries was given top marks in the influential and highly respected Virginia Tech Lab safety assessment. In fact, it ranks number one out of the hundreds of helmets they’ve tested.

A low-volume design helps keep the helmet’s weight down to a svelte 310.7g (size large) and combines huge front vents and large exhaust ports.

The vent in the front-centre is 60mm wide by 30mm deep and the further five front-facing vents run the length of the crown.

At the rear, six large exhaust ports help expel air. Internally, deep channels and a new herringbone pattern of cutaways further reduce heat build-up.

Even the transparent polycarbonate reinforcing arch (called Aura II) helps channel air and reportedly reduces drag (by 4 per cent over the older Aether Spherical model, says Giro).

Because of the extensive channelling, there’s just a U-shaped pad at the crown and a full-length brow pad.

However, remarkably, the Aries is one of the most comfortable road bike helmets I’ve tried.

The DryCore brow pad has an internal silicone bead that pushes moisture out to your temples, away from your eyes. It’s a simple idea that works exceptionally well.

Fit adjustment from the minimal Roc Loc 5+ Air Fit system is good, with a three-position anchor for 1.5cm of vertical and 4cm of horizontal adjustment, plus the dial to control the volume.

The thin, silky straps have adjustable Y-shaped anchors, so they should clear your ears and won’t interfere with your cycling sunglasses. With no ‘cap’ or stitched strap ends, it’s easy to pull the straps through the buckle accidentally though.

Finishing details include full coverage of the exposed EPS from the shell, rubber grippers on the glasses ports and stealthy reflective details on the rear.

Giro Aries Spherical Helmet bottom line

On the road, the Giro Aries Spherical is the coolest helmet I’ve ever ridden in: on a few trips to Spain it was exceptional.

Back home in the British winter, I found its air channelling so efficient that I had to wear a hat underneath.

It’s wonderfully comfortable, too, and incorporates MIPS technology to keep you safe.

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It’s just a shame it’s so pricey.

Product Specifications


Price br_price, 5, 3, Price, AUD $500.00EUR €320.00GBP £290.00USD $300.00
Weight br_weight, 5, 6, Weight, 310.7g (L), Array, g
Brand br_brand, 5, 10, Brand, Giro


Features br_Features, 11, 0, Features, Sizes: S, M, L
Vents: 24 Vents and deep internal channelling
Colours: Matte Ano Blue; Matte Ano Harbor Blue Fade; Matte Black; Matte Carbon/Red; Matte Metallic Coal/Space Green; Matte White
MIPS br_MIPS, 11, 0, MIPS, Yes
Helmet type br_helmetType, 11, 0, Helmet type, Road