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
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.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.
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 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.
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.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 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.
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.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.
You can probably assume it's just about all of them. I'd guess Bell for starters.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.
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.You can probably assume it's just about all of them. I'd guess Bell for starters.
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.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.
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.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.
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.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.
thickness is less important than density.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.
I don't usually click on video links, but i had to to figure out what you were on about. Took me a while.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.
is there something wrong with them, besides maximum comfortness? I don't see any certifications listed on their website though...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.
can't acces youtub at work. care to enlighten the rest of us?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?
No, they both matter.thickness is less important than density.
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.No, they both matter.
OK, that's fine, but when considering some helmets with really thin liners like the D2 I think it's a major consideration.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.
giantfro said:from someone who rides moto and dh on a weekly basis, i can tell you that all my crashes on both moto and dh feel the same. a digger to the head riding dh is usually worse of an impact than my crashes riding moto. should i ride with a dh helmet on a slow trail ride because the speeds are slower? the logic displayed above does not make any sense to me. more speed does not equal a worse crash.
despite this article, ill keep rocking my SHOEI VFX-W best helmet money can buy and it shows. one helmet for everything.
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.OK, that's fine, but when considering some helmets with really thin liners like the D2 I think it's a major consideration.
feeling the same != being the same.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:
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.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.