6D started back in 2011 with a fire for ingenuity in the protection space. That fire continues to burn today as the brand expands its helmet line with the Alterra, their first lightweight full face helmet. While most helmets in this category are considered a “trail full face” the DH and E-Bike safety ratings the Alterra has received deserves the full face only naming convention. While 6D is still making a name for themselves in the MTB market, they are widely adopted in the moto community and can be seen at pretty much every trailhead.

About The 6D Alterra Helmet

As with all other 6D helmets, the Alterra gets the ODS treatment, which stands for Omni-Directional Suspension. ODS is 6D’s own technology, allowing the inner shell of their helmets to move in 3 dimensions. When compared to the widely known MIPS system, ODS has a leg up when it comes to dispersing compression events. The MIPS system allows for energy to be transferred on two axes – front to back and side to side. ODS not only accounts for this but also adds in a third axis, in and out. This adds extra protection to your noggin, say if you were to hit a tree or have a sudden impact where all your momentum is instantly stopped.

One of the key things 6D has done to create this 3rd axis is use a EPP layer instead of an EPS layer. EPS foam is great for single impact absorption, but they act like packing bubbles, and once impacted they are no longer functional. EPP acts like memory foam: when impacted the material will give way and absorb force, but it bounces back to its original state resulting in a product that can take multiple impacts over the course of its life.

Editor’s Note: With that said, if you hit the dirt hard enough to ring your bell, getting a new helmet is the smart thing to do.

The EPP liner sits within a Carbon Fiber roll cage on friction-reducing caps. These then sit on a moulded tower, which suspends the inside layer underneath the outer shell. With this suspension, both rotational force and impact force can be dissipated in the opposing direction of impact. While this undoubtedly aids in major impact scenarios, this system also works wonders on the lighter side of impacts. The amount of force needed to get the system to start moving is extremely low.

One aspect 6D found to be a failure point on competitors helmets was the chin bar, especially when used in colder temperatures. The Alterra’s Carbon Fiber chin bar flexes and moves with impacts in these colder conditions, where competitors can crack and fail and cause further injury. The helmet body is a mix of Polycarbonate and Carbon Fiber. The chin, brow and lower rear portion of the build is Carbon while the back and topsides are Polycarbonate. This blends a mix of durability and reduced weight, taking the size medium just over 700g with a full downhill safety rating.

One last safety aspect we spotted on the helmet that can easily go unnoticed is the EPP padding placed under the chin extending back past where your ears are. This is put there to help protect your body (collarbone and sternum) from the helmet itself. A small detail that goes to show 6D has really put rider safety through the ringer.

The helmet boasts an insane amount of vents, 32 to be exact! If you are overheating in this thing, it might just be too hot to ride. Vents are placed all over the helmet, allowing for maximum airflow. Should you sweat out a big few weeks of riding, the internal Ionic+ comfort liner is easily removable to toss in the wash. The Alterra is equipped with the Fidlock Closure System for easy one handed use.

Available in sizes XS-S (53-56cm) to XL-XXL (59-62cm) and in a choice of six colors, the 6D Alterra retails for $395.

THE DIRT

Upon unboxing the 6D Alterra full face, I was shocked at how light it felt in my hands. When first putting it on, that lack of weight was very apparent. Holding my benchmark trail full face – the Smith Mainline – next to the Alterra, it was not even a competition when it came to weight, and I already considered the Smith to be acceptably light for an all-day adventure. Preferring subdued colors, the raw Carbon Fiber chin bar 6D used looks rad. I am glad they left the carbon weaves exposed on this!

When it comes to comfort and fit, the Alterra took the win over the Mainline, with a slight caveat. The overall comfort is great, with no pressure points no matter where I push down on the helmet. Their comfort lining is just that, comfortable. The only negative I can give the helmet’s fit is that the cheek pads sit a bit high, resting just above my lower jaw bone. With that said, the Smith Mainline’s cheek pads sit even higher and put pressure on the lower portion of my ears. I have had this issue with many helmets, and attribute it to my ugly face structure. After a climb on the Mainline I can’t get the helmet off fast enough, whereas the Alterra faded into the background and was not intrusive.

Thankfully I did not need to test out the ODS system, and fingers crossed both myself and you readers never do. But knowing the technology behind the system has been developed to go above and beyond what MIPS is doing brings peace of mind to every ride. I never really noticed the system moving around on my head while riding. The 6D Alterra was secure and stayed in place on every ride. Also, this helmet was silent, with not a single squeak or knock. We have yet to have used this helmet in the dead of summer subjecting it to dust day in and day out, so the jury is still out on if the Alterra will continue to be silent. My Mainline sure is not…

While I still have yet to use this helmet on a 90 degree day, the 32 vents strategically placed around the helmet give me confidence that it’ll provide stellar ventilation. I am most excited about the large brow vents, since this is where most of my heat build up seems to happen. To have a full downhill safety rating with this level of breathability and the ODS system is impressive.

The three-position visor stayed in place even with me overshooting a giant step down on the 120mm Trek Top Fuel. In the highest position there is ample room to store your goggles if you are into that sort of thing. And speaking of goggles I used the helmet with 3 different brands including our very own Loam Wolf Providence Goggle. I’ve found no fit issues so far. 6D also mentioned they are working on a 3D-printed accessory for an under visor POV camera mount. I also told them to please build a chin mount option, so keep your eyes out for that!

HOW IT COMPARES

As I mentioned above for me the biggest competitor was the Smith Mainline as it is a helmet I have owned since our 2021 Emtb shootout. It’s safe to say that I’ve had plenty of ride time in that thing! Between these two helmets, the Alterra takes the win across the board when it comes to fit, comfort and safety in my eyes. However I do personally like the looks of the Mainline more, as well as its affordability.

The Wolf’s Last Word

When it comes to safety, the 6D name is something I have been told to look into for a long time now. I regularly see moto guys using 6D both at the professional level and here locally. After talking with Robert Weber, one of the founders at 6D, as well as getting my hands on their product, the claims my friends have made make a lot more sense now. While it might not be the prettiest diamond on the shelf (though this is of course subjective), it will likely keep your smile nice after a major sampling of Mother Earth. I look forward to getting this helmet out in the dead of summer for more riding. I think what they have done with the ODS system is very cool and hope to never test it, but if and when the time comes I have a little bit less to worry about.