At £250 the Giro Switchblade is more expensive than the Bell Super 3R but it feels more substantial, and still good value considering it’s 2-for-1.

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Usually in life it’s sensible to steer well clear of products that purport to do two jobs in one, as they have a habit of being terrible at both tasks.

But there are exceptions, such as the Giro Switchblade, for instance – one of a new breed of helmet that converts from full-face to open face via a removable chinbar.

I say new breed, but the Switchblade actually first appeared back in 1998, when skinnies in the sky and hucks to flat were the pinnacle of mountain biking cool.

With the advent of enduro racing, the desire for greater protection on descents, alongside increased ventilation on liaison climbs, has made the convertible lid relevant again, and fortunately the new Switchblade is a lot better second time round.

Giro Switchblade: one helmet for all your riding needs

Giro Switchblade review

At the heart of the Giro Switchblade is a Montaro trail lid that’s been extended at the back and the sides to drop well below your occipital lobe, as well as cover your ears and part of your cheeks.

Giro calls it the Full-Cut, and the end result is that it looks a lot like a motorcycle trials helmet – so be prepared for the hilarious stream of Dougie Lampkin/pizza delivery guy gags from your mates.

It’s bottom-wrapped to protect the EPS, there’s a MIPS liner to protect the brain against rotational forces, and a proper D-ring style chinstrap. For further peace of mind, the Switchblade passes the ASTM F1952 downhill helmet standard with and without the chinbar.

Compared to most full-face helmets, there’s a reasonable array of vents, including something called Wind Tunnel cooling to direct airflow over the ears. It works, to a degree, and I’ve worn it on warm days without overheating.

But ultimately you have to be prepared to run hotter in the Switchblade owing to the increased coverage, thicker pads and wider chinstrap. On the other hand, the Switchblade makes cold winter rides a toasty delight.

The chinbar is made from a mix of plastic, rubber and steel, and is very flexible. As such it’s easy to strap to a pack at the bottom of a long climb. Attaching it to the helmet – don’t try putting the Switchblade on with the chinbar installed, as it’s a really tight fit and you’ll probably lose an ear – is a little fiddly at first, but we soon got the hang of it.

The trick is to use both hands and locate the two small dimples by the ear. Then guide the circular metal studs on the chinbar into the slots alongside these dimples and push until they click into place. The chinbar then pivots down into position, with the lower clips again locating with a positive click.

Slow and methodical is the best approach, because try and rush and you’ll either get frustrated or the chinbar won’t attach securely.

Chinbar or no-chinbar, the Switchblade instills a genuine sense of safety and security. You really are wrapped within a protective cocoon that makes you feel naked in most trail helmets by comparison. The comfort and fit is superb, too, with no unwanted movement, and you don’t ever need to torque up on the Roc Loc Air DH retention system to keep it stable.

While the visor is long, it has plenty of scope to be angled out of the way, and even tilts back far enough to park your goggles beneath. And if you want to shoot video, there’s also a POV visor with integrated GoPro mount included in the bag.

At £250 the Switchblade is more expensive than the similar Bell Super 3R but it feels more substantial, and still good value considering you’re getting a single helmet that can be both worn on your regular weekly ride, as well as days out at the bike park and holidays in the alps.