While speed can be intoxicating, it's never a good idea to lose your head. POC doesn't want you losing your head, so they designed their helmets to be exceptionally safe, and stylish too. The POC Cortex DH helmet is the crown jewel of their work. POC designers started with the helmets they made for ski racing. Realizing that the demands of protection in that realm aren't the same as the demands of bike riding, they knew they had to do something different. To them, one of the biggest issues is ventilation; cyclists desperately need a cool head, while skiers do not. If the vents are too small, summertime riding can be oppressive. Still, ventilation cannot come at the cost of protection. Vents that are too large will expose the riders head to more risk than is appropriate, especially for freeriders and downhillers who face potential injury from branches and jagged rocks. POC also realized that single layer hard shells were sometimes culpable in whiplash injuries because they tend to bounce, and micro shells, while great at absorbing impacts, were not durable and offered little in the way of penetration protection. So they went in a new-direction that combined the best of both worlds -- double-overlapping shells. They use the acronym VDSAP for their system (Ventilated Double Shell Anti Penetration). From the outside in, POC's double layer Cortex DH Helmet has a lightweight carbon fiber outer shell. Then there's the Aramid ballistic Penetration Barrier, or APB in POC speak. It's a layer of penetration-resistant Aramid (basically Kevlar, the same as found in bullet proof vests) between the outer shell and the liner shell. Further in, a thin polycarbonate shell covers the EPP liner material. As a result of this trifecta of protection, the outer shell can be thinner than usual, which makes it both lighter and better at absorbing blunt impact energy.With the double-shell design, POC positions the vents so that the ones on the outside of the Cortex DH helmet draw air into channels that flow to the inside vents. This way, the vents next to the skull are not exposed to the outside. There are also ear vents that allow for decent hearing while keeping your ears protected. The chinguard is designed to keep your face and teeth ready for family photos, yet it's far enough away from your mouth and well ventilated so you can breathe easily, even when you have to ride up short climbs.Perhaps the most interesting aspect of the Cortex DH Helmet is its use of MIPS (multi-directional impact protection system) technology. Basically, safety engineers know that most bike crashes deliver your head to the ground, not straight down, but at an angle. These oblique impacts create problems as your helmet hits the ground, sticks, and your brain continues on its original trajectory to a degree. While we have a natural cushioning layer of cerebrospinal fluid that allows some shear between the brain and the skull, POC helmets with MIPS imitate our own fail-safe elements a
I have been using the POC Cortex DH full faced helmet for several months now, and it has been comfortable, durable and safe. The helmet offers a plethora of protection and features, which are all engineered with safety in mind, and my crashing and tumbles have shown it to be an ideal candidate for the wicked world of rocky gnarliness and speed. Continue reading →
from Boulder, CO (PNW transplant)
Date Reviewed: November 13, 2009
Strengths: The best money can buy.
Weaknesses: None, assuming you can live with the protection vs cooling compromise.
Helmets are a bit personal. No matter how many little fitting pads they put in, if it doesn't fit your brain bucket, it will not work well. It took me a while to find something that worked. I will spare you the details and instead refer to this MTBR post: http://forums.mtbr.com/showthread.php?t=486086
Since that post, I have had several crashes. Two big ones. The first big one was a head first landing at Whistler (first run of the day of course). The second was on some local gnar here in Colorado. The first one ruined my goggles, knocked the wind out of me (stagger...stagger...can't...breathe...) and permanently bent the visor so I looked like Flavor Flav sans clock. The second head strike occured when helmet vs rock occured. In neither crash did I feel like my brain was rattled. After the second crash as we were shuttling back up, I noticed a chunk in the side of the helmet where it had done its job protecting my most valuable asset. I believe the POC Cortex (mine is the 'Flow' version) offers the best protection this side of a moto helmet. TLD and THE also make excellent products, the other helmets I tried didn't fit me very well or didn't impress me with their comfort or quality like these three did. 10/10 for quality, contruction, design. 8/10 for cooling. A compromise that I endorse, if I need cooling I will wear my XC lid.