Giro Coalition Spherical

Giro Coalition Spherical Lightweight Full Face Helmet

Photos Pete Roggeman

Giro is launching their new lightweight full face today: the Mips-equipped Coalition Spherical. The chin bar is not removable, but my review sample weighs in at a competitive 777 grams (size Medium) and has a well-ventilated chin bar (25 vents in total) and internal channeling to help funnel hot air surrounding your head out the back of the helmet.

Whether you're after a helmet for trail riding that takes you into territory closer to your limits or for a bit more safety than a standard half shell, the Coalition Spherical is a full-featured contender at the top end of the spectrum. Removable chin guards seem to be losing favour to the new crop of lightweight full faces, due in large part to the demands of the ever-growing number of e-bikers out there, and among its many safety certifications, the Giro Coalition Spherical includes NTA certification, which was developed for use by riders that spend a greater amount of time at or above 32 kph / 20 mph.

Giro Coalition Spherical Specs & Features

  • 800 grams size M (our size M review sample weighs 777 grams)
  • Spherical Technology powered by MIPS
  • Halo Chinbar System
  • Fidlock Buckle
  • DryCore sweat managing brow pad
  • Two sets of different thickness cheek pads
  • 25 vents connected by deep internal channeling
  • Certifications: CPSC, NTA, ASTM-1952-DH, ASTM-2032-BMX, CE EN1078

Halo System Chin bar

Lightweight full face helmets are gaining traction with some trail riders out there, but for those of us that prefer a half shell, there are a few obstacles to overcome, namely ventilation, weight, and comfort. In the pursuit of these traits, the design of the chin bars on some of these helmets have delivered less than stellar protection. Giro has addressed this with a new tech they're calling the Halo System chin bar, which uses Pebax (a family of elastomers comprised of of rigid polyamide blocks and soft polyether blocks) and elastomeric bushings built into the helmet's EPS layer and designed to absorb and dissipate impacts. Giro claims this lets their new helmet exceed standard chin bar deflection certification by almost 200%.

Mips Spherical

Giro has used Mips Spherical in its high end helmets for about five years. It uses Mips' trademarked low-friction slop plane between an EPP and EPS foam layer - like a ball and socket that have different densities in order to help deal with impacts of differing speeds. Here's an article I wrote about MIPS Spherical and how it works. Below, a brief animation from Giro using their new Coalition Spherical as a model.

Giro Coalition 4

Lots of vents, including in the chin bar. I appreciated the easy air flow near my mouth which is one of my biggest complaints with full face helmets when working hard.

Giro Coalition 5

Good venting out the rear as well.

Giro Coalition 9

Fit adjustments can be made using supplied cheek and back of head pads that come in 25 and 30mm widths.

Giro Coalition 10

Fit and Comfort

The Coalition Spherical does not use a retention control device, instead relying on adjustable pad thicknesses - 25 and 30mm thick - located at your cheeks and the back of your head. I used the thinner 25mm pads to get a snug, comfortable fit with no pressure points. My head tends to fit most helmet manufacturers' head forms, and Giro is no exception. The 59cm circumference of my skull is usually at the upper end of a Medium but I always try to go with a snugger fitting helmet for good fit security in case of a crash as well as lower weight and bulk.

A Fidlock buckle is used for the chin strap, and it's my favourite method; once you get used to it, the ease of single-handed unclipping (and clipping with a little practice) is fast and smooth.

I've only had the Giro Coalition Spherical for a week, so my riding time is limited so far, and since it's February, it's hard to really evaluate the efficacy of the vents, the DryCore brow pad, or the odour control of the Ionic+ pads, but I'm a sweaty guy so I'll have thoughts on those once it gets warmer. However in the few rides I have worn it, there is clearly a lot of air moving through it and its light weight and fit makes it comfortable enough that I think I may have found a full face I'll be happy to wear on those tweener rides that span the line between mellow and merciless.

When it's cooler out (below about 6º C) I prefer the added cheek and ear coverage, although it means I can't easily use ear buds while climbing (it's possible, just not ideal). Field of view is perfect and although it's a full face and therefore designed to be used with goggles, it works fine with shield-style glasses as well. The goggle strap is not necessary to get a snug fit, so go ahead and wear your glasses (on pain of conviction by the fashion fuzz).


The Giro Coalition Spherical comes in four colourways: Matte Black


Matte Dark Shark Dune


Matte Metallic Coal Mineral


and Matte White Ano Blue.

The Coalition Spherical lightweight full-face helmet is available in three sizes (XS/S, M/L, and XL/XXL) and four colourway options (Matte Dark Shark Dune, Matte Black, Matte Metallic Coal/Mineral, and Matte White/Ano Blue).

Giro Coalition Spherical - $325 US MSRP / €339,95.

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Although I don't love any of those colorways, it's a good looking helmet. 

How would you compare the breathability compared to a Bell SuperDH convertible helmet?

As I was advised, it turn out I rarely convert it and just run full face most days so a lighter, better venting full face is on my list of upgrades. 

Good review.


I haven't used the Super DH convertible so I can't compare. But the Coalition Spherical is about 300 grams lighter, which is a huge difference. I'm going to give it the nod in breathability based solely on the weight savings, but that's speculation. The weight difference, however, is massive.


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