I can give you some feedback on a 30mph crash with a Oakley ARO5 MIPS helmet…they work!!!
I had a car pull out on me from a junction as I was coming downhill. My head made solid contact with the B Pilar as my shoulder went through the window. I was then out cold and I fell directly backwards onto the road…helmet was cracked front to back.
CT scan in the hospital was completely clear
(I was just happy they found a brain)
Yup, just like with crash tests, I think it is time to up the ante for helmet manufacturers.
If you’re having a crash with a car - doing 15mph or any speed really the impact force could be massively greater than hitting the ground at 30mph.
I’ve tried both the WaveCel road helmets on, I don’t feel theses helmets ventilate well perhaps because the cell material channels doesn’t really match the direction of the helmets vents. I know that’s not as important as safety but it is something to consider.
I could be wrong here, but it was my understanding that the speed you are travelling at on your bike is not what matters here. It is the speed your head travels at while falling (off bike). I think that’s what the impact case speed numbers are referring to.
Testing at 20, 25, 30, 35, 40 mph should only matter if you’re flying straight into a solid object (wall, back of a truck, etc).
Again, this is just my understanding.
There are many common accident patterns where you impact the road with essentially the speed you are traveling at, e. g. when you get flipped over the handlebars (which has happened to me on two occasions, one time I was traveling 30-35 km/h).
The larger point @Nate_Pearson was making, and that I think it completely valid, is that these are high-end helmets for serious cyclists who regularly travel faster than the crash test speed at which helmets are tested. The current crash tests mandated by the various regulatory agencies around the world are designed more to replicate accident patterns of average cyclists, i. e. not us.
The speed is particularly significant, because the (kinetic) energy which has to be dissipated by the helmet grows quadratically with the speed, i. e. a crash at 30 km/h vs. 15 km/h involves four times the energy.
Exactly. Thank you.
Take a look at standard testing for motorbike helmets - they are tested (in the EU at least) at 16.8mph (7.5m/s). This is because the speed that your head hits normal to an obstruction is much lower than you’re forward velocity in the vast majority of crashes.
The type of helmet you’d need to pass tests at much higher speeds would be crazy and you’d need to crash directly into the corner of a building for that to happen.
I’m pretty sure that all current helmets would be crap in a direct collision with a concrete wall at 50mph.
Mike
@Jonathan Are you aware of any aero testing data regarding the Ventral Spin vs the new Ventral Air Spin? POC’s site says both are aero and for the Ventral Air Spin say “the Ventral Air SPIN works to enhance a riders aerodynamic profile and minimize drag”.
Hard to know exactly what that means but it would be helpful to know how much of a difference there really is between the two.
A little more digging and I found this quote from POC comparing the aerodynamics of the Ventral vs Ventral Air on Cyclingtips.com.
“Of course, it depends on speed, angle etc but our results show that at 35 to 40 km/h the Ventral Air is comparable to the Ventral in terms of reduced drag, after 40km/h the Ventral starts to track away, as you would expect for an aero helmet as it has improved aerodynamic performance due to enhanced airflow control thanks to the internal channels, Venturi effect and exterior trailing edge.”
If the aerodynamic benefit is minimal, it might suggest that the superior cooling and lighter weight of the Ventral Air make it a better XC MTN bike helmet.
Perhaps outdoor temperatures might be the deciding factor. It looked like the EF team had Ventral’s on today in the Tour of Flanders but wore Ventral Air’s during the Tour Down Under which was very hot.
This is a population average for the typical population. The people participating in this forum are not part of the typical population. The better analog here would be to consider crash test standards for bike race helmets instead.
I don’t claim to know how the subset of sporty riders is different in terms of typical impact speeds (which obviously also depends on the cycling discipline, mountain biking is different than road riding), but I hope that Trek’s announcement will spur innovation here and motivate other bike helmet manufacturers to go way beyond the tests mandated by the various certification authorities. Few people buy 250+ € helmets to pootle around town.
Just to put a little more perspective on motorbike helmet testing, the most up to date FIM tests for helmets in use in MotoGP use a direct impact speed of 8.2 m/s (30 kph). Given that crashes happen at vastly higher speeds than in cycling, I don’t think there would be much case for using higher impact speeds for cycling use.
Would you really want to wear a motorbike helmet next time you’re out in 30 degree heat and blowing out you’re arse climbing up an alpine col?
Mike
I’ve been wearing my Bontrager XXX WaveCel for a few weeks now. I was previously wearing a Kask Protone, so big difference in weight and I noticed it the very first ride within the first mile. But I got used to the weight difference really quick.
Issues I’ve noticed with the helmet that I did not see mentioned here was the lack of a way to mount a headlight to the helmet and you cannot scratch the top of your head, lol.
Other than that, I’ve had very little complains of the helmet. I know a lot of people are debating the claims right now, and I’m not a scientist to prove the numbers wrong or inaccurate. I do believe the helmet is a lot more safe than my previous foam helmet and I greatly appreciate what Trek is trying to do (advancing safety). I literally wear ONE piece of gear to protect myself, might as well make it a good one.
As far as ventilation goes, I have felt the breeze hit my head on a few road rides, but the highest temps I’ve been in so far this year was a MTB ride in the mid 70’s and my head felt fine (and I have plenty of hair). I have a feeling that the ventilation will be similar to my Kask but probably not as good as some other less aero helmets.
Thanks for explaining what modern MotoGP testing standards are. I don’t want to overemphasize the higher speeds aspect in crash tests, perhaps the speeds bike helmets are tested at are indeed also alright for people like us who do sports.
The broader argument still stands, though, I’d like to see improved testing procedures that include more common accident patterns for fast riders like us. If that doesn’t translate to faster impact speeds, then this is what science says.
I think that’s a false binary here. In the MTB world there is much more variation amongst helmets as far as coverage goes, everything from road-like helmets to full face helmets. So for example the MTB equivalent of the road helmet I have now has more coverage in the back of the head. If research shows that e. g. more coverage in the back keeps me safer, I’d get that heavier, safer helmet in a heart beat. And despite hot temperatures, I was never one to take my helmet off during climbs (as some MTBers do).
If one is going 50kmh or say 30mph, short of slamming directly into a wall or vehicle w/out any braking, your head is not going to be going anywhere near that fast on impact.
Usually when we crash, our heads are still moving horizontally. Thus the force vectors are mostly horizontal vs vertical. Hell, I would not be surprised to see statistics showing the majority of serious head injuries are at low speed since there would be less skidding/sliding (horizontal) to dissipate the force of impact. I think I said that right?! 
Exactly right @KickrLin. People are mistakenly assuming the forward speed translates directly into the helmet impact speed. That’s not true. And it’s because of the reason you said, vector direction and speed.
The head impact speed will almost always be less than horizontal speed unless you slam into a wall or other vertical item. The typical contact with ground will be greatly reduced from horizontal speed. In some cases, it may even have very little to do with that horizontal speed.
What matters more is the path the head takes and the acceleration caused by the rider movement and motion that may affect the head speed.
Yes, I don’t think that moving to a higher impact energy is that important in helmet design for cycling.
As you go from 6.25m/s to 8.2m/s the energy to be dissipated is multiplied by 1.7. That’s a lot more energy to get rid of in a small amount of material and one of the reasons that motorbike helmets don’t look like cycling helmets. They also have to pass penetration tests and absorb impact from more angles so my comparison wasn’t very fair.
The issue of coverage is a different one altogether and some people put more emphasis on that than others - you can have decent coverage (and impact resistance) with good ventilation at the lower impact energy because the construction doesn’t change.
I remember when EPS foam helmets started making an appearance in rock climbing - the tests were fairly primitive with a single flat plate drop test and a single penetration test carried out on the very top of the helmet as a simulation of rock fall, rather that head strike. There was one helmet that that a relatively small section of EPS foam on the very crown of the head that could absorb the impacts as prescribed by the tests, but everywhere else it was just a shell. It looked that part but would have been useless in a head on rock impact.
Mike
Well, I took your point not literally either, because I saw what you were aiming for and you made your point quite well. I didn’t know that such low-seeming speeds are still practically relevant for sporty cyclists — although I would still feel safer if there were a larger margin.
Out of curiosity, how come you know so much about helmet standards?
In addition to coverage there are quite a few other factors to consider. The last helmet I killed was while mountain biking, the shell and the EPS layer were cracked because after my front wheel got stuck in between rocks and I somersaulted on top of a rock. Fortunately the helmet did his job and died in the line of duty, protecting the gooey matter in between my ears in the process.
I must admit I was intrigued as to why the impact test speeds were so low and decided to do some research. I’m an engineer and like to know about these sorts of things.
Mike
It was clear that you had at least some background in physics or engineering (I inferred because you knew that kinetic energy scales with the square of the speed).