The POC Cortex Flow is a lightweight, very well ventilated full-face downhill helmet. It is constructed from expanded polypropylene rather than the more standard expanded polystyrene, meaning it is more resilient to crashes. The shell is constructed from fiberglass and comes in tons of different colors to match your kit.
Luke Lydiard takes a lap through Mammoth Mountain's "Deep End" in the POC Cortex Flow.
Photo: Jeff Fox
The Cortex is not as well padded as some of the other helmets, which gives it a looser fit and makes it jiggle a bit at very high speeds. The looseness improved airflow and was one reason why the Flow took the highest score in our ventilation test. This helmet is free from pressure points but simply lacks the plushness of some of the other helmets like the Bell Transfer-9 or Troy Lee D3, which took the top honors in our comfort test.
We found that this helmet has a shape which fit riders with oval shaped heads a little better than round heads. If you know you have an especially round head, we highly recommend the Troy Lee D3 which has a much rounder fit and scored much higher in our test.
The Flow has large voids around the ears which are comfortable and make getting the helmet on a bit quicker but possibly provides less protection.
Luke Lydiard getting sideways in the POC Cortex Flow and a Leatt DBX neck brace.
Photo: Jeff Fox
The Flow's visor has a large range of motion, which means that it can be placed optimally for different head shapes and riding conditions. The visor is about about the same length as the longest ones in our test, though it is slightly narrower. We found it to have plenty of coverage at the corners. Our two favorite visors were found on the Giro Cipher and Troy Lee D3, which both have very large and well attached eye shields. The Troy Lee helmet also came with a replacement visor in case you break one.
The visor is attached and pivots around a burley aluminum screw at either side of the helmet. These screws can be manipulated with fingers or better yet, a coin. The up/down position of the visor is controlled by another aluminum screw which threads through a slider tab beneath the center of the visor. The adjustment screw is one of the easiest to locate blind and is easily manipulated with full-finger gloves on.
This visor is constructed from a flexible plastic, which survived a sliding crash directly to the top of the helmet.
The Flow's visor has a wide degree of articulation and is locked in place with a thumb screw which passes through a tab beneath the visor. We found this to be one of the better visor adjustment methods.
Photo: Luke Lydiard
At 35.8 ounces, the Flow is the second lightest helmet we tested. Only the Bell Sanction weighs less. These two helmets offer a lower level of protection than the other helmets in our test, however. Though these helmets are light, neither of them meet the ASTM-F1952 standard for downhill mountain biking. All of the helmets we tested, including these two, mee the CPSC 1203 and CE EN 1078 standards for regular cycling helmets. The lightest helmet we tested which is ASTM-F1952 certified is the Fox Rampage, which also won our Best Buy Award and tipped our scale just one ounce heavier than the Flow at 36.8 ounces.
Luke Lydiard enjoys the POC Cortex's light weight and excellent ventilation while shredding pavers.
Photo: Jeff Fox
This is the best ventilated helmet we tested, and took the top score in this test. We feel this is partially due to it's loose-ish fit but mostly due to the well designed vents, air channels, and meshy liner. The Flow also has large open areas around the ears and the huge breathing hole in the chin guard which further improves ventilation and breathing. The excellent ventilation makes this a good option for aggressive enduro races where riders would benefit from the added coverage of a full-face but still need to do a bit of pedaling.
The POC Cortex Flow took the highest score in our ventilation test which makes it a good option if you push or pedal up more than you ride lifts.
Photo: Jeff Fox
The Cortex Flow meets the CPSC 1203 and CE EN 1078 which are standards for cycling helmets in the US and Europe respectively. All of the full-face downhill helmets as well as the half-shell mountain bike helmets in our recent Mountain Bike Helmet Review also meet these two standards.
The Cortex is one of only two full-faces in our test which, as far as we can tell, does not meet the ASTM-F1952 standard, which is a higher level of protection than the CPSC or CE standards. Simply by being a full-face, the Cortex will provide more coverage than a half-shell, but we would feel more confident getting gnarly in a helmet which meets a higher standard like the ASTM-F1952. The majority of the helmets we tested meet the ASTM. Another helmet which does not is the Bell Sanction, which Bell recommends only for groms and BMX. Basically they are saying it's a light-duty lid. Bell recommends the Transfer-9 or Full-9 for full on gnarfests, and we do to.
The Cortex has very large voids around the ears which result in less contact points between the helmet and the head. The shell of the helmet also has an oval opening over each ear which is covered by a piece of fabric tape on the inside. The thin sheet of plastic which attaches the cheek pads has small holes punched in it outside the ears. POC claims that these "Ear Chambers" improve hearing and balance. We did find that this helmet restricted our hearing less than other helmets, thought we suspect it's because of the large gaps around the cheek pads rather than the holes in the shell. We can't say that we noticed any improvement in our balance. We can say that we would prefer that there was more protection between our ears and a sharp rock than what the Cortex provides.
The Cortex Flow has a large hole in the shell over the ears which POC claims improves balance and hearing as part of the helmet's "Ear Chambers". The hole is lined on the inside of the helmet with a thin piece of cloth tape which is sandwiched between the shell and a portion of the cheek pads.
Photo: Luke Lydiard
Our test helmet came with an extra set of cheek pads as well as a nice white storage bag for the super organized types. We swapped the check pads out with the extra set after the first set became pretty packed out and funky after a year or so of riding.
The Cortex Flow does not have any type of camera mounts, though the smooth exterior of the helmet has a lot of room for an adhesive mount to be attached. For something as jarring as downhill riding, adhesive mounts are less wobbly than clip on or velcro plugs anyway, so we can't say we miss an integrated mount like the one found on the Giro Cipher.
The Flow was one of the helmets we had the privilege of taking a full-on header in while testing.On a windy day at Mammoth Mountain's Bike Park one of our testers was wearing this helmet on a jump line he has done many times. Midair he was caught by a wicked gust of wind and blown completely off the track landing completely sideways. He went down on his head and shoulder which resulted in a large scrape and chip in the fiberglass. The interior foam was not damaged and the tester rode away uninjured. We felt that the integrity of the helmet was not compromised and we kept using it for testing.
One of our testers took decent header in the Cortex Flow which resulted in some chipped paint but didn't seem to damage the fiberglass shell or polypropylene foam.
Photo: Luke Lydiard
One unique thing about the Cortex Flow, as well as its big brother the Cortex DH, is that POC uses an expanded polypropylene foam liner rather than the usual expanded polystyrene. POC claims that this type of foam can sustain multiple impacts and that these helmets do not necessarily have to be replaced after an impact. Let's be honest, nobody that rides downhill is going to replace an expensive lid after every scuffle with the ground, which is a good reason to consider a helmet designed for multiple dirt sandwich consumption.
The Flow was the helmet that our testers likely logged the most ride time in, and it very faired well. We did notice that the check pad foam is a little less dense than on other helmets, and packed out a little quicker than average. We ended up swapping out the pads with the extra set it came with after about a summer of shredding.
The Cortex is one of two helmets we tested which uses a plastic buckle rather than metal "D" rings to fasten the helmet. The other is the Bell Sanction, which is the only other helmet in our test which does not meet the ASTM-F1952 standard for downhill racing. We didn't have any problems with the durability of either of the plastic buckles as opposed to the D rings, but we did appreciate the ease of use. It's definitely much quicker and easier to fasten a plastic buckle rather than blindly thread double D rings each time you put the helmet on. The real question is wether they are less secure or safe. Since all of the ASTM-F1952 certified helmets use metal, we are assuming that the ASTM feels that it is.
Light downhill mountain biking, pushing or pedaling up due to it's light weight and better ventilation, aggressive enduro races.
This is is the second most expensive helmet we tested at $230. While this is one of the lightest and best ventilated helmets, we feel that if you are serious about downhill and have $200 to spend that you would be better served with either the Bell Transfer-9 or Giro Cipher. Both of these helmets retail for $30 less and meet the stricter ASTM-F1952. For the most protection for your buck, check out our Best Buy Award winner, the Fox Rampage which meets the ASTM-F1952 standard while costing only $130.
The Cortex is a lightweight, well-ventilated and very stylish helmet but it lacks the protection of helmets which meet the more stringent standards. For this reason we feel that this helmet would be best suited towards less aggressive downhill riding. We also think it would make a good choice for gnarlier enduro courses where riders would benefit from face protection but don't want the weight of a full-on downhill helmet.
POC also sells the Cortex DH for a whopping $500, the most expensive full-face mountain bike helmet we know of. The POC website describes the Cortex Flow, which we've tested here, as the little brother of the Cortex DH, which looks similar to the Flow but is actually a very different helmet. The DH uses MIPS technology to significantly up the protection factor but this increase in protection comes at the cost of noticeably increased weight and decreased ventilation. In addition to the two cycling helmet certifications of the Flow, the DH also meets the CE EN 1077B which is a standard for alpine skiing and snowboarding. As far as we can tell, the DH is not certified to the ASTM-F1952 standard.