As the only thoroughbred downhill helmet in the entire test field, the Giro Insurgent Spherical is something of an outsider in our lightweight full-face helmet comparison test. As a result, weight and ventilation only play a secondary role in our final verdict. We’re more interested in the fit, comfort and safety. How did Giro’s downhill lid fare against the test field of lightweight full-face helmets?

Giro Insurgent | not convertible | 1,156 g | € 390 | Manufacturer’s website

As a purebred DH lid, the Giro Insurgent has significantly more padding and fewer vents than all of the other competitors in this test. Retailing at € 390, it’s the most expensive model, and at 1,156 g in size XL/XXL, also the heaviest. Adjustment is limited – the only way to adapt the fit is using different cheek pads. These can be pulled out from the bottom of the helmet in the event of a crash, making it easier to remove the helmet. The Insurgent is packed with plenty of safety features, including the MIPS Spherical System, which consists of two independent shells, seamlessly connected by a low-friction MIPS sliding layer. In a crash, the outer and inner shell can rotate independently and move by a few millimetres to reduce the impact. The inner shell is made of a softer, more elastic EPP foam, which takes care of slower impacts, while the outer EPS shell is meant to mitigate faster impacts. In addition, the lower edge of the chin bar is lined with a soft material, which is designed to prevent collarbone injuries. The visor is flexible, and has a tool-free adjustment, albeit within quite a small range. The Giro is the only helmet in this test to rely on a D-ring buckle, which takes a little getting used to, and can be particularly finicky to use with gloves. On the other hand, the system is extremely secure and tightens even more when pulled – coming undone unintentionally is not an option!

With the D-ring buckle, the chin strap threads through a couple of metal rings. While it might be a little fiddly, it’s extremely secure!
The MIPS Spherical system consists of two shells, which are made of different types of foam and move independently.

When first wearing the Giro Insurgent Spherical, your head feels well enclosed and protected. The fit is excellent, with the generous padding on the inside of the helmet and around the chin strap preventing annoying chafing and pinching. No other helmet in this test inspires as much confidence as the Insurgent The head is safely tucked away inside the shell, with the padding hugging your cranium all around, ensuring a high subjective feeling of security and safety. However, the high level of protection comes at the expense of ventilation, making long climbs a rather sweaty affair, and ensuring noticeably less ventilation on pedal-heavy trails, especially if you wear goggles. When first wearing the helmet, you also feel the extra weight, especially if you’re used to riding with a lightweight half shell helmet. However, you’ll quickly get used to it, and it starts to feel normal after a little while. Even so, the Insurgent has a narrower range of applications compared to the other full-face helmets in this test, which detracts from its all-round qualities. For park rats, however, it’s a great helmet.

The Giro Insurgent Spherical is a purebred downhill helmet – and a very good one too! However, this has both its pros and cons. Amongst the disadvantages are the additional weight, and most noticeably the limited ventilation. On the other hand, the Giro Insurgent impresses with its excellent padding, top fit and unparalleled feeling of security. If you ride mainly with uplifts, the Insurgent Spherical is a top choice!


  • Top fit
  • High wearing comfort
  • Countless safety features


  • Relatively heavy
  • Not the best ventilation

For more information, visit

For an overview of the group test: 9 lightweight and convertible full-face mountain bike helmets in review

All fullface helmets in test: Bell Super Air R Spherical (Click for review) | Bluegrass Vanguard Core Edition (Click for review) | Fox Proframe RS (Click for review) | Giro Insurgent | MET Parachute MCR (Click for review) | POC Otocon Race MIPS (Click for review) | Specialized Gambit (Click for review) | Troy Lee Designs Stage (Click for review) | Uvex Revolt MIPS (Click for review)

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Words: Simon Kohler Photos: Peter Walker

About the author

Simon Kohler

​​Simon loves speed. He has many years of racing experience as a longboard downhill skater, blasting down alpine passes on his board. In the meantime, he’s swapped four wheels for two, charging down trails and bike park lines aboard his mountain bike instead. He’s savoured some of Europe’s finest trails on various road trips through the Alps. Having lived in Austria for some time, he knows the local Austrian bike parks like the back of his hand. He’s a tech nerd through and through, using the skills and know-how from his engineering degree and his attention to detail to put the latest bikes and components through their paces for our reviews. As an early riser and self-declared muesli connoisseur, he lives his life powered by oats and the strength of his legs.