What you guys think? I found it interesting.
http://www.pinkbike.com/news/DH-Helmets-vs-Motocross-Helmets-Which-Is-Safer.html
http://www.pinkbike.com/news/DH-Helmets-vs-Motocross-Helmets-Which-Is-Safer.html
DH helmet vs MX helmet
- Thread starter Optimax150
- Start date
Its moot for us giant headed people; there isnt a DH helmet in the world that comes close to fitting me.
XXXL HJC MX Helmets (CLX4, CLX5N and now CLX6) [XXL+ are DOT but not SNELL]
If I could get into a D3, that would be that.
XXXL HJC MX Helmets (CLX4, CLX5N and now CLX6) [XXL+ are DOT but not SNELL]
If I could get into a D3, that would be that.
So, what's up with a DH helmet that is SNELL rated?
I'm doing a highly accurate thumb pressing test with all the helmets I buy, and some of the hardest styrofoam has been in Lazer DH helmet. I'm pretty sure that helmet is not good in preventing concussions.
Nowadays I ride with Acerbis MX helmet that has significantly softer styrofoam than the Lazer helmet. That said, at least Troy Lee D2 has even softer styrofoam than my Acerbis.
All I wanted to say is, don't buy into the general statement "all DH helmets are better in small impacts than any MX helmet".
Nowadays I ride with Acerbis MX helmet that has significantly softer styrofoam than the Lazer helmet. That said, at least Troy Lee D2 has even softer styrofoam than my Acerbis.
All I wanted to say is, don't buy into the general statement "all DH helmets are better in small impacts than any MX helmet".
The difference between my old D2 and the new D3 I have is so night and day. I felt protected before, but always on the thin side. The new skid lids are so technologically advanced at this point, I think it all comes down to comfort and style choices.
Once ASTM came out, most every DH helmet on the market is as much protection as you can ask for (while still remaining functional) without wearing the Jack in the Box hat.
Once ASTM came out, most every DH helmet on the market is as much protection as you can ask for (while still remaining functional) without wearing the Jack in the Box hat.
I have an old Carbon D2 (which I love) and recently tried on a carbon D3; the D3 was the most unconfortable helmet that I've tried on. I was getting pressure points dead center of my forehead and at the opposite position at the base of my skull. Too bad because it's a pretty nice helmet and was certainly very light.
Tell me about it!!! Take a look at GMAX. They are way lighter than HJC and have 14 vent holes. Motorcycle superstore always has them for under $100.00. not Snell . but DOT as well.
I had that problem too with the L. I was exactly between L and XL measuring my head diameter. Than I tried the size bigger. So comfortable. Tight, yes but no pressure points and absolutely no movement. The thing is that the M and L share one shell and the XL and the XXL share a bigger one. Did you try the bigger size too?
i like my snell helmet, mainly because I don't have to spring for a second helmet to go ride motos.
This was my experience also. I could get the L on, but I had nasty pressure points just forward of my temples, and just behind my ears. The XL felt great. I normally wear a M/L D2.
That's what I heard from other guys. If your D2 M/L fits fine, go with the XL.
Or even better: Measure your head diameter and opt for the bigger size if you are in between.
Or even better: Measure your head diameter and opt for the bigger size if you are in between.
this is a really good article that everyone should read. without getting into a lot of technical detail, it explains the challenge that helmet makers face - making a helmet "stiff" enough to withstand high speed impacts, without making it so "stiff" that you sacrifice performance at low to medium speeds.
Stiff is in quotes because its not really the right term, what's being evaluated is the impact transmissibility of the foam they use; which is a result of several factors (one of the main driving factors being the density of the foam used; denser foam = more "stiff")
Stiff is in quotes because its not really the right term, what's being evaluated is the impact transmissibility of the foam they use; which is a result of several factors (one of the main driving factors being the density of the foam used; denser foam = more "stiff")
I sure would love to now which MX helmet companies were involved in the boycotting of the MX magazine that ran the original article. I'd make damn sure they never saw a penny of my money again.
I think this article left out a really important aspect of head protection, rotational forces which causes a lot of damage on your brain. As far as I know only Poc has taken that seriously with their MIPS-system. If they weren't so damn ugly I would wear one (fashion over brain!) but I really believe it's the safest DH lid.
Another thing is that a lot of carbon lids are a lot stiffer than composite lids which might make them less safe in some cases but of course safer in other.
A third thing is the question about weight. While my TLD Air mx helmet is pretty damn heavy, My One Gamma mx helmet is lighter than my old Giro DH helmet so you can't say that a DH helmet is lighter than a MX helmet. In most cases it's probably true but you should make sure it is if you think that's important to you.
All I'm saying is that it might not just be DH vs. Mx but also model vs. model and material vs. material.
Another thing is that a lot of carbon lids are a lot stiffer than composite lids which might make them less safe in some cases but of course safer in other.
A third thing is the question about weight. While my TLD Air mx helmet is pretty damn heavy, My One Gamma mx helmet is lighter than my old Giro DH helmet so you can't say that a DH helmet is lighter than a MX helmet. In most cases it's probably true but you should make sure it is if you think that's important to you.
All I'm saying is that it might not just be DH vs. Mx but also model vs. model and material vs. material.
finally getting people to realize more isn't better is a big first step in the right direction.
Regarding materials, the majority of companies are still using EPS for the liners. The shells (carbon, etc) are only provide puncture resistance; they don't really contribute to the impact absorption.
also, MIPS is its own company; their technology is used in more than just the bike industry. POC just happens to be the only company licensing the technology. TLD, 661, Giro, Bell, any of them could work with MIPS and develop a helmet with that technology.
http://m.youtube.com/watch?v=zMIEHMU1kwo#/watch?v=-A8oGQMTIF8
950g
Lighter than a tld bike helmet.
More comfterable. And everyone and their bro doesn't have one.
950g
Lighter than a tld bike helmet.
More comfterable. And everyone and their bro doesn't have one.
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I agree. It would be in an instant boycott from their products. And even if they fixed them and made them better, I'm still not entirely sure I'd be willing to buy from a helmet company I didn't trust in the slightest.
You can probably assume it's just about all of them. I'd guess Bell for starters.
that's unfortunate and probably true. Being the optimist that I am, I'm going to assume its all of them except the brand I currently own.
I too had a M/L D2 and bought a large D3 online. At first it was incredibly tight, in fact I had a headache after 10 mins of wearing it. I was worried I had bought the wrong size. However after persisting and wearing it some more, it now fits like a glove. It should be comfortable and well fitting after packing out, not before. No exact science but I'm glad I didnt get the XL.
I agree with you. And every head is different. The problem was that even after taking out the padding only the shell made pressure points in front where the venting sits and in the back.
So if you have the possibility to try one, make sure that the shell alone sits comfortable. Than put the pads in.
Like you said, the padding is tighter at the beginning and will pack out.
Something else to consider:
A crash at 60mph vs. 20mph doesn't mean you're just going to slam your head into a stationary object at that speed. Something more important is that you'll be more likely to sustain multiple impacts crashing at 60mph and rolling/ragdolling than at 20mph. A fall at 10mph to a dead stop against a tree is a totally different acceleration in the brain than wiping out at 90mph and skipping across dirt/gravel a dozen times or so. Design consideration for single cycle vs multi cycle fatigue.
I think the point the article makes about the head mass of the rider corresponding correctly to the foam density is the most important one though. The selected foam density is directly affected by both input momentum and kinetic energy (products of mass and velocity). With the range of foam densities available and the range of masses among adult riders heads, I think it's very easy to have too soft or too hard of a foam - regardless of riding speed.
At least a helmet/foam selection based on head mass is due to a known variable. You never know what speed you're going to crash at.
A crash at 60mph vs. 20mph doesn't mean you're just going to slam your head into a stationary object at that speed. Something more important is that you'll be more likely to sustain multiple impacts crashing at 60mph and rolling/ragdolling than at 20mph. A fall at 10mph to a dead stop against a tree is a totally different acceleration in the brain than wiping out at 90mph and skipping across dirt/gravel a dozen times or so. Design consideration for single cycle vs multi cycle fatigue.
I think the point the article makes about the head mass of the rider corresponding correctly to the foam density is the most important one though. The selected foam density is directly affected by both input momentum and kinetic energy (products of mass and velocity). With the range of foam densities available and the range of masses among adult riders heads, I think it's very easy to have too soft or too hard of a foam - regardless of riding speed.
At least a helmet/foam selection based on head mass is due to a known variable. You never know what speed you're going to crash at.
sanjuro's avatar makes me feel like I'm being lectured to by a VIP.
My problem with that article is that it largely neglects the ASTM 1952 standard, which was created mostly to settle this entire debate, I though. There was a really good post by a helmet designer here on the monkey, I'll see if I can find it. Anyways, the PB article makes only a passing mention of the standard, which I thought was really applicable to DH (chinbar guidelines, multiple impact vs. single, etc.). I would love to see more investigation into it, because if I'm ignoring an aspect of safety by going with the ASTM helmet, I want to know.
Yes you never know but you can find the most probable speed. Get a gps tracker and ride with it for a few days. Check the avg speed. Even for fast tracks like Maribor I rarely get my avg. speed even close to 30kph.
Though to be honest after my last crash I will only buy POC helmets. I killed my Cortex DH but after slamming full speed from 2m face town onto a rock my head didnt feel anything. In most helmets Im dazed and my head hurts at least a little with smaller crashes.
This gets brought up every year. It comes down to a personal choice. I've been wearing a TLD SE for 6 years now. I'm on my 3rd one.
Last year I had a really bad crash, right on my forehead. Full stop from 15+ mph into the face of a small jump. Took the entire crash force with visor. I hurt, but I had no dizzyness, and no headache. The foam in the helmet was completely destroyed. I'm pretty confident that with a helmet with thinner foam, would have had a concussion. Regardless, this is the type of "slow speed" crash were a MX helmet is suppose to be worse, yet it protected me wonderfully.
Last year I had a really bad crash, right on my forehead. Full stop from 15+ mph into the face of a small jump. Took the entire crash force with visor. I hurt, but I had no dizzyness, and no headache. The foam in the helmet was completely destroyed. I'm pretty confident that with a helmet with thinner foam, would have had a concussion. Regardless, this is the type of "slow speed" crash were a MX helmet is suppose to be worse, yet it protected me wonderfully.
thickness is less important than density.
All I know in all of this, is someone recommended a helmet that rhymes with sparrow, and that scares me.
But then again, this is RM.
But then again, this is RM.
I don't usually click on video links, but i had to to figure out what you were on about. Took me a while.
I was chatting with a Bell rep the other day and he was talking about how helmet fit can affect things like fatigue and even arm pump. Loose helmet requires more upper body/neck muscle use and blood flow to keep stable, ergo more arm pump (in MX riders).
Any input Stick?
is there something wrong with them, besides maximum comfortness? I don't see any certifications listed on their website though...
can't acces youtub at work. care to enlighten the rest of us?
No, they both matter.
Many MX helmets use multiple density EPS liners, like my Shoei VFX-W. It also has a shell that is designed to flex, yet resist penetration. See Aim+ shell construction and dual layer EPS liner in link below for details.
http://www.shoei-helmets.com/Helmet.aspx?VFX-W&h=17&t=2
I have never taken a really hard hit to my head, but I used to wear a TLD D2 and went to a Shoei VFX-W. With the small hits I have taken, I can say the D2 is downright scary compared to the Shoei. The relatively minor hits I have taken with my Shoei feel like nothing, the hits I have taken with the D2 transmitted much more force over a smaller area of my head. Which brings up another point, it doesn't matter how good the helmet is if it doesn't fit properly.
I do think the new TLD D3 is a huge improvement over the D2, it is much closer to a SE than a D2 though...
Read what I wrote; I didn't say thickness didn't matter, just that it's less important, implying that density is more of a driving factor (which it is). I don't have the book with me now, but I can dig up the equation used to predict impact transmissibility of an expanded foam substrate.
OK, that's fine, but when considering some helmets with really thin liners like the D2 I think it's a major consideration.
On another topic, I also question the "fact" that moto riding means much harder impacts. While there is that possibility, this quote from PB is very interesting:
giantfro said:
i'll have to dig up the equation, but the point is, a 1% change to density will have more of an impact on the trasmissibility than a 1% change to thickness.
it's possible to have identical transmission rates between two completely different thicknesses of foam, by altering their density.
feeling the same != being the same.
and more speed can (and does) equal a worse crash. Momentum (mass*velocity) is also a factor in the force of an impact.
Does anyone have or know of somewhere that has a list of ASTM 1952 helmets? Also, given that the same helmets are being sold in Euro-landia and Oceania, is there an equivalent certification in Europe to ASTM 1952?
My helmet was manufactured in 2008. It has taken a few medium hits. I think given its age and those hits, I'd be happy getting a new one. But I'd like it to meet the newest standard. Anyone have any thoughts?
Off the top of my head, I think that the following meet ASTM 1952:
- D3
- Spec Deviant
- Giro Remedy
- Bell Drop
I'd like to know about the OGK Kabuto and O'Neal Airtech, and Kali...
My helmet was manufactured in 2008. It has taken a few medium hits. I think given its age and those hits, I'd be happy getting a new one. But I'd like it to meet the newest standard. Anyone have any thoughts?
Off the top of my head, I think that the following meet ASTM 1952:
- D3
- Spec Deviant
- Giro Remedy
- Bell Drop
I'd like to know about the OGK Kabuto and O'Neal Airtech, and Kali...
i'm pretty sure the POC cortex dh helmet meets ASTM 1952.
Actually, E = .5mv^2 is the relevant equation in determining the impact force and subsequent g-loads associated with an impact, and relates to momentum as E = p^2/2m. Momentum (p) is a vector quantity while E is a scalar. Energy is basically the rate of change of momentum. Biggest issue being that the force of impact increases at the square of velocity, not at a 1:1 rate like the momentum equation might suggest.
I would argue that the way you crash has MUCH more influence than the speed of travel in most cases, but obviously in some crashes traveling faster does mean you will hit harder. This means that the decision of what helmet you choose has MUCH more to do with how you crash than what type of vehicle you are traveling on. Since you can't choose how you will crash, then the entire premise of the PB article is flawed. IMO this article is total bullsh!t and oversimplified to the point it makes no sense. Every single piece of anecdotal (real world) evidence from people who ride both mx and dh, and people who have used both types of helmets point to the mx helmet preventing concussions moreso than a dh helmet.
I would also argue that the quality of the helmet matters quite a bit too, and it is possible that some mx helmets offer better protection than many dh helmets regardless of impact speeds. So this is another factor that is not dealt with in the article.