Leatt DBX 4.0 joins the lightweight full face club, a helmet for enduro racing or bike park days, packed with big vents, comfy padding and other features.

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There are two forces now driving helmet design, the desire to produce the most breathable and coolest lid and appeal to enduro racers, and the need to reduce the risks of multiple concussions, the dangers of which are becoming more and more understood. It’s these two conflicting ambitions that is driving the incredible innovation we’ve seen in the past few years, stretching helmet makers to design clever products like the Giro Switchblade with removable chinbar, and the ultra-light Fox Proframe and TLD Stages full face.

The helmet has another protection system up its sleeve, Leatt’s proprietary Turbine Technology that’s designed to better absorb rotational energy and help prevent concussions — they say it reduces the forces to your brain by up to 40%. It does this through the 10p sizes rubbery discs dotted inside the helmet, they’re there to float and turn independently of the helmet and provide a slip plane.

Thankfully, while these Turbines combine with the padding to actually make contact with your head you don’t actually feel them, making the DBX 4.0 a very comfortable place to be, without pressure points or hotspots. I found the fit excellent, and you can tailor it to your bonce shape with the additional foam inserts provided. Part of the weight saving Leatt has achieved over a traditional full face must come from a reduction in padding inside the lid — there’s no all-encompassing foam bed to sink into, instead the pads make contact at strategic points such as around your cheeks, the brow and back of the head. Despite this the DBX 4.0 is solid as a rock when you’re riding, comparable with a full on gravity lid like the Fox Rampage.

Less padding also means more opportunity for airflow, something this helmet has in waves. Never fear though, it still passes the full face DH helmet certification standards. The mouthpiece grill is detachable for extra flow but I left mine in as an insect screen. Securing it all to your head is a padded strap and Fidlock buckle that’s a great addition, no more fiddling with a D-link when your hands are frozen.

On the outside I reckon the DBX 4.0 is handsome, it’s sleek and fast looking, and combined with the integrated visor that’s designed to break off in a crash there’s little to dig in to the ground and disrupted the slip plane effect. The visor stays just out of your range of vision but it’s not adjustable, which is my first bugbear — there’s not enough space to park your goggles just below the peak. The second is that the DBX feels closer to a traditional DH style of helmet than the new breed of ultra-lights — it’s not significantly light enough. The TLD Stages and Fox’s Proframe beat the DBX 4.0 handsdown— the former is 690g in size medium and the latter 747g, against the Leatt’s 987g. The Fox is over £50 more expensive though, and the TLD £100 extra, making this helmet great value.