Today, 6D officially announces its entry into the lightweight full-face MTB helmet arena with the carbon Alterra. At 710 grams and $395, it's been a long time coming for the brand that has elevated helmet safety in both cycling and motocross. Dig into the specs and info below followed by our first-ride impressions.

Highlights

• Patented Omni-Directional Suspension™ (ODS)
• In-Molded carbon fiber chin bar and internal roll cage
• Polycarbonate shell
• Multi-Impact EPP inner Llner and EPS outer liner
• EPP sternum and clavicle crash pads
• lonic+ Antibacterial Comfort Liner
• Goggle compatible with under-visor storage
• Directional venting and sub-channeling
• Extra-Large rear directional exhaust vents
• Fidlock closure system
• 3-position snap-away adjustable visor
• Travel bag included
• Multiple comfort liners and pad sets
• Sizes: XS-S (53–56cm), M-L (56–59cm), and XL-XXL (59–62cm)
• Six colorways
• Weight: 710g M/L
• MSRP:$399 USD

First Ride Impressions

I've had the chance to spend a handful of rides in cool weather in the 6D Alterra, and my first impression is that it is incredibly light and very comfortable. Since interviewing Bob Weber, 6D's founder, a couple years ago and learning about their development story, I've continued riding in 6D's ATB-2T half-shell during trail rides. The safety of the 2T made it an easy decision to wear, despite being heavier and larger looking than other half-shell trail helmets. The 2T fit my head well and the weight was never an issue. When the Alterra was announced, I was excited to try it out, as most trail rides these days warrant full-face coverage.

I chose to wear the 2T because of 6D's ODS design that protects your noggin against fast and slow impacts. It's more than just a rotational, two-dimensional slip-plane. There is also *suspension travel* built in to help mitigate impacts on the head and brain that foam alone can't. Not every mountain bike crash is so high-speed that it will crush the foam the way it's designed. Additionally, most modern tests only measure a helmet's effectiveness at these higher impact speeds. Slower speed hits can still result in concussion or head injury, and 6D's tests prove ODS will perform better than other designs under the same conditions. 

I wear a M/L in the 2T helmet, and it hugs my head well, so I requested the M/L Alterra for testing. Unfortunately, my head wouldn't quite fit into the pocket of the M/L Alterra shell even with the smallest pads installed. A L/XL was sent out and it ended up fitting great with the 18mm pads. The helmet comes with two pad thicknesses, so most riders should be able to dial-in fit even if you're between shell sizes. 

Once the helmet was on, it was easily forgettable thanks to its light weight and pad configuration. The padding relief around the ears gives the Alterra a feeling similar to that of a half-shell. The pads don't put any pressure on your ears, and there are no pads to squeeze your ears past when putting the helmet on. 

The Alterra's svelte nature gives the illusion that you're not wearing a full-face helmet. At 710g for a size medium, it might not be the lightest full-face enduro helmet, but its very competitive. For comparison, Fox's Proframe RS weighs 820g, TLD's Stage weighs 690g, and Smith's Mainline weighs 770g (for size M helmets).

A Fidlock closure is always a welcome feature, and the padded strap covering the strap is a nice touch to relieve any under-chin pressure points.

What's The Bottom Line?

The Alterra takes 6D's trusted and effective ODS system and packages it into a breathable, lightweight enduro full-face helmet. It has all the bells and whistles you'd want from a premium helmet, matched with a comfy fit that can make you forget you're wearing a full-face. And most importantly, it delivers safety that's class-leading against various impact speeds. We were big fans of 6D's ATB-2T trail helmet, but moving forward, the Alterra will be our go-to for most rides, as you don't have to sacrifice comfort to receive extra protection.