 Poster: A snowHead
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Must admit I've always assumed that fitting something to my helmet was likely to reduce its effectiveness. Not to imply that I haven't used a helmet cam at times (or fitted lights to my bike helmet) but I did it thinking that it was a compromise. I'm a bit surprised anyone thinks it isn't detrimental to helmet performance really.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Not sure about the gopro mount, but I know, my mount for the Contour that i use has a break away function for the camera and the mount is a very flat piece of plastic.
I had a couple of falls last season both of which I landed on my helmet, on each occasion my camera came off ! Is this not the case for gopro cameras as well?
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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I'm just not buying it - if the cam mount had any effect on the outcome of Schumachers accident at all it'd be marginal to the point of inconsequential. Its natural to want to explain and apportion blame when we see accidents that strike close to home so we can say "it wouldn't have happened to me because I'd have done X differently" or "it could've been me so I'll not do X from now on" - But I just cannot see how this theory fits the narrative in this case.
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As far as I understand (as an ski helmeted engineer who reads stuff) : the main risk to the human brain is NOT impact, but rotation.
The helmet does help with direct impact - the shell (thin skin of hard plastic) is designed to flex, and the thick bit squash some, absorbing energy - reducing the deceleration of your brain.
It is also designed to twist on your head, and be smooth to slide on the impacting surface. If you grab your skull and spin it, most of your brain stays still, and the trauma happens at the brain surface wherebits of it are attached to your skull. This the maximum shear and forces are, and shear is bad - its what makes scissors work so well.
This is also why I worry when I see kids (and to some extent adults) on bikes with a helmet that makes their head about 50% larger - a helmet which is not smooth. On a glancing impact (and most falls are not going to be straight) the extra radius will add more twisting force. (I stand to be corrected here - because the larger fulcrum will also act 'slower' so the net accellerative torque may be the same ?)
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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On the point of helmetcam videos : I enjoy watching them to see where the operator is looking - yes, so many times I have seen keen skiers doing stupid things like catching air off a piste side 'feature' ... without checking the piste is clear...
And no, you cant rely on peripheral vision, in goggles, without wing mirrors, whilst focusing on the gnarly air you are about to hit.
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I wonder if there is more "showing off" or taking risks while filming yourself.....just a thought
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I'm calling cowdoo. The adhesives used on the mounts aren't all that strong; the camera will come off before breaking the helmet.
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| ansta1 wrote: |
| PeterGee wrote: |
| So go pro'ing is a personal choice. What I don't get is the denial here of the risk. A bit odd! |
By whom? |
Philwig (the physics seems incredible) and MogulMonkey, (as strong as a go pro mount may be i seriously doubt that this was the reason to the severity of the accident) to name two from above.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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alex_heney, that's not a denial of any risk.
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Either way I expect Nick woodman (Mr gopro) will be sending in the boys shortly.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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Alastair Pink, that link doesn't seem to go anywhere, is it behind a firewall?
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Quote from that link
"In early trade on Monday, shares of GoPro were down as much as 10% amid another day of broad market weakness, with the Nasdaq losing the most ground among the major averages."
So gopro shares may have taken a bigger hit, but the general trend was down also.
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You know it makes sense.
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| ansta1 wrote: |
| PeterGee wrote: |
| So go pro'ing is a personal choice. What I don't get is the denial here of the risk. A bit odd! |
By whom? |
Not trying to offend. We all partake in a sport some would consider risky, but that is our choice. Whether you choose to fit a Go Pro to a helmet, or even go without a helmet, is 100% your choice. But this is a reasonably public forum, where a lot of people (including me on other threads) look for advice and guidance on an array of matters. So when you offer an opinion on here, it does make sense to me consider the potential impact of that opinion.
So to the matter in hand. After months of investigation, the current professional opinion *appears* to be be leaning toward the camera mount contributing the helmet's failure to do its job. Now whether that is enough for you to consider not mounting a camera, is really up to you. But I do struggle with a few posters writing this analysis off, on a forum for the consumption of others, without I would suggest understanding enough to do so. As I say, make your own decisions by all means, but I find denying what is being said, is a bit odd.
By the way, I am not saying I agree the mount was the issue. But if they say it is, I would definitely take that on board. I would also say though that helmet manufacturers are normally quite careful about usage. In other domains, for instance, if you crash a motorbike, they would absolutely expect you to write off your helmet and replace it. Wonder how many of us have had a bad off in the mountains and get the need to go get a new helmet.
Peter
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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| clarky999 wrote: |
| I'm calling cowdoo. The adhesives used on the mounts aren't all that strong; the camera will come off before breaking the helmet. |
I'd disagree. I had an iON the Action on loan from Sportpursuit to film my motorcycle racing. It mounted on top of the helmet, protruding up in a manner similar to the GoPro, unlike my Drift which side mounts and stays much closer to the helmet.
It caught on a branch at about 50mph, and the mount and adhesive was strong enough to pull the helmet up so violently that I bit my tongue due to the chin-strap slamming my mouth shut, I couldn't see where I was going as all I was looking at was the inside of my chin-piece and the branch gave way before the mount did. I took it off there and then and didn't use it for the rest of the race.
All the cameras I'm aware of use the same 3M adhesive pads. Whether the mounts to which they are attached are as strong is a different question.
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Poster: A snowHead
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lampbus
"As far as I understand (as an ski helmeted engineer who reads stuff) : the main risk to the human brain is NOT impact, but rotation. "
That's not what I've read (a ski helmeted former engineer that reads stuff). If I believed that I wouldn't wear a helmet - I really don't think they help with rotation. My reading suggests that helmets offer increased protection against impact at some COST of increased rotational torque. Former outweighing the latter. Helmets (bike and recreational skiing) are really specced to deal with your head being dropped on the floor from about 6 foot
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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forgot to say, this is why I think mounting stuff on helmets is possibly detrimental. If you land directly on the mount (rather than shearing it off) it is likely to focus the force on a narrower area of the helmet reducing the benefit from compression of the foam in dissipating energy
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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jedster, that's certainly the case in most helmets but the newer generation have protection from the rotational impact of a crash. Can't remember what the acronym they used off the top of my head (no pun intended).
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MIPS and it's not really protection from rotational impact, but more of reducing forces when helmet gets "stuck" on surface during crash and your head is keep moving on. And it depends if this really works or not, considering all race helmets are without it, and even majority of high end helmets is without MIPS, while lower end helmets has it.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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| jedster wrote: |
| forgot to say, this is why I think mounting stuff on helmets is possibly detrimental. If you land directly on the mount (rather than shearing it off) it is likely to focus the force on a narrower area of the helmet reducing the benefit from compression of the foam in dissipating energy |
Yes and no.. The helmets are designed to accept and dissipate a force from an impact with an object of a certain size. If the mount and whatnot is larger than that tested size then the penetration SHOULD be less than what the helmet has been designed and tested to withstand. If the mount is smaller, and so the area and pressure more concentrated, then yes, I agree with you.
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[quote="PeterGee"]
| ansta1 wrote: |
So to the matter in hand. After months of investigation, the current professional opinion *appears* to be be leaning toward the camera mount contributing the helmet's failure to do its job. Now whether that is enough for you to consider not mounting a camera, is really up to you. But I do struggle with a few posters writing this analysis off, on a forum for the consumption of others, without I would suggest understanding enough to do so. As I say, make your own decisions by all means, but I find denying what is being said, is a bit odd.
By the way, I am not saying I agree the mount was the issue. But if they say it is, I would definitely take that on board. I would also say though that helmet manufacturers are normally quite careful about usage. In other domains, for instance, if you crash a motorbike, they would absolutely expect you to write off your helmet and replace it. Wonder how many of us have had a bad off in the mountains and get the need to go get a new helmet.
Peter |
It's not a proffessional opinion though, it's a journalists opinion. And quite likely a journalist that doesn't ski at that.
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| jogi wrote: |
| MIPS and it's not really protection from rotational impact, but more of reducing forces when helmet gets "stuck" on surface during crash and your head is keep moving on. And it depends if this really works or not, considering all race helmets are without it, and even majority of high end helmets is without MIPS, while lower end helmets has it. |
My understanding was that the intention of MIPS was exactly that, when there is an impact that causes the brain to rotate (hence my use of the term rotational impact) in the skull, whether through an oblique impact or 'dragging' then the system allows for a degree of buffer within the helmet to reduce this impact on the head and brain.
more info at http://www.mipshelmet.com/
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| clarky999 wrote: |
| It's not a proffessional opinion though, it's a journalists opinion. And quite likely a journalist that doesn't ski at that. |
A journalist's opinion based on the words of a 15 year old he spoke to by telephone, reportedly, but even those details are now being questioned:
| Quote: |
"The problem for Michael was not the hit, but the mounting of the GoPro camera that he had on his helmet that injured his brain," Jean-Louis Moncet told radio station Europe 1 over the weekend.
Moncet was reported to have spoken to Schumacher's son, Mick, but the journalist denied this in a tweet later. |
http://uk.reuters.com/article/2014/10/13/uk-gopro-stocks-idUKKCN0I224D20141013
I guess the ENSA report will never be public then?
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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[quote="clarky999"]
| PeterGee wrote: |
| ansta1 wrote: |
So to the matter in hand. After months of investigation, the current professional opinion *appears* to be be leaning toward the camera mount contributing the helmet's failure to do its job. Now whether that is enough for you to consider not mounting a camera, is really up to you. But I do struggle with a few posters writing this analysis off, on a forum for the consumption of others, without I would suggest understanding enough to do so. As I say, make your own decisions by all means, but I find denying what is being said, is a bit odd.
By the way, I am not saying I agree the mount was the issue. But if they say it is, I would definitely take that on board. I would also say though that helmet manufacturers are normally quite careful about usage. In other domains, for instance, if you crash a motorbike, they would absolutely expect you to write off your helmet and replace it. Wonder how many of us have had a bad off in the mountains and get the need to go get a new helmet.
Peter |
It's not a proffessional opinion though, it's a journalists opinion. And quite likely a journalist that doesn't ski at that. |
Sp you think he is making it up all on his own! Wow! As I say, *appears*!!
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Re the question of stickers on helmets being a bad idea, I remember years ago the advice being not to attach them to motor cycle helmets. Those helmets are designed to be perfectly smooth so that they slide smoothly when impacting a road. Stickers could cause the helmet not to slide smoothly with the consequent risk of twisting/breaking the neck. I know we are talking about snow rather than roads, but even so no-one would think of putting anything other than wax on their ski/board bases!
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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| Big Dave wrote: |
| but even so no-one would think of putting anything other than wax on their ski/board bases! |
So you haven't heard the Reblochon story, then..?
admin?
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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Sounds intriguing .... Do tell
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You know it makes sense.
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From what little I know, it was a "special" ski prep by one or two certain snowHeads....
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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Mounting a camera mount on any helmet could potentially cause additional damage, generally the helmet works (at least in part) by spreading the load from the point of impact across a larger area of skull, now if you have something mounted to the outside of the helmet and that object is the first thing that hits then instead of spreading the load the load will be concentrated at a specific point on the helmet, this might split the helmet before it gets the chance to spread the impact load across the skull.
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Poster: A snowHead
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| Quote: |
Stickers could cause the helmet not to slide smoothly with the consequent risk of twisting/breaking the neck. I know we are talking about snow rather than roads, but even so no-one would think of putting anything other than wax on their ski/board bases!
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NEW PLAN: Wax your helmets! thats way it will slide better!
(that sounded less dirty in my head) 
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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it is a natural feature of rocks generally to be less than rounded. One might even consider them occasionally jagged.
So if we are considering the concentration of forces through a small impact zone, there may be other contributory factors.
Just sayin'
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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Hello everyone. Hope you're not all hyperventilating about snow this coming season, as I seem to be every September onwards!
I read about this in a Greek news article a couple of weeks ago. Was surprised to see it reported in the British media, with litigation involving GoPro perhaps a big issue, but it is believable; motorcycle helmet users being told for years never to tamper with their headgear, as it would interfere with their design/ strength. Be interested to see where it leads and still hoping Schumi recovers.
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You need to Login to know who's really who.
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PeterGee,
Three issues seem to be important from what limited information has flowed into the public domain
1
schumacher's injury was severe, so the forces were likely to be high, helmets work up to a certain threshold value, and then don't protect significantly. This is well known and the mechanisms well-understood. The Snell and ANSI tests are designed around thresholds, and cycle helmet manufacturers do a lot of destructive testing.
2
As I have posted before in order to raise awareness, well-established research (from the 1940s-on) suggests that rotational injury is the most significant threat to brain function (although brain stem separation was a serious issue in NASCAR etc); as some of the posts above indicate. However, helmet manufacturers have been slow to respond to rotational issues (not least because of the nature of the certification tests) - POC has its MIPS system which deliberately addresses this limitation. Note that the shiny thin covering on contemporary cycle helmets is there to allow the helmet to slide over surfaces rather than 'grabbing' and causing rotational injury.
3
The helmet is reputed to have split, but although splitting is common in cycle helmets, only plastic deformation really absorbs energy in a way which best protects the brain: see:
http://forum.ctc.org.uk/ucp.php?mode=login&sid=4148ced20e4a5dd7f5bfc3f27d14765e:.....on cycle helmets
It seems that helmet use increases the accident rate and also increases impacts to helmets. This double effect means there are many cyclists reporting hitting their helmets.
see
http://www.cycle-helmets.com/head-helmet.doc
Breaking of EPS
http://www.sciencedirect.com/science/ar ... 7506001758
Helmets in general are not designed to limit rotational acceleration and Lane reported "it has been recognised since the work of Holbourn (1943) that rotational acceleration of the head plays a major part in brain injury". Lane details the threshold limits suggested by Lowenhielm of 4500 rad/sec/sec for AIS 5. AIS 5, being critical injury level. StClair and Chinn suggest a maximum rotational level tolerance for human adult head 10000 rad./sec/sec, children’s tolerance may be lower.
They tested monkeys to see if rotational or linear acceleration was the main cause of brain damage, the results suggested rotational acceleration.
In tests for rotational accelerations, they measured both peak normal force and tangential force. The normal force is compressing the material and tangential effectively tearing it apart. Maximum values where 5817N and 2997 N (1300 lbs and 670 lbs force). the load is applied over the impact area, roughly say 50mm x 50mm perhaps, compression load, 2.3MPa or 320 lb/sq in. Tangential load may be applied over a smaller area due to vents, assume 30 x 30mm perhaps, 3.3MPa or 430lbs/sq in. Roughly data on EPS suggests from a 5800N load a displacement of 20mm may occur. Roughly the tensile strength may be about 50psi range but they could have a wide variation in actual manufacturing, say 25 to 70 psi.
The area under impact may be subject to a load 8 times higher then its basic strength (430 v 50) and could start to fracture or tear before fully compressing. All this would occur in a fraction of a second and could be subject to high speed filming to see what actually happens. I think some helmets are reinforced with glass fibre.
It is almost entirely chance to where an impact may occur and the resulting linear and rotational accelerations levels. Without a helmet, a lower risk of impact. It will probably be part of helmet research for the next decade or more.
So...Schumacher case; the splitting could be associated with the go pro mount, but cycle helmets have split many times without having a go pro mount associated with the split. Rotational damage is the most likely form of injury in the schumacher case, although we just don't really have enough to go on. Splitting and rotational injury are not incompatible and can occur together.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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The assumption that rotation was a factor in this particular case is a BIG assumption. While what you say is true for those circumstances, I've not seen anything to suggest a particular impact model came into play in Schumacher's case.
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A quick look back at some articles describing the crash say he hit his head on the right-hand side. It is quite unusual to mount a gopro on the side of a helmet instead of the traditional teletubby look...
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It appears the journalist which linked the GoPro to the Injuries and helmet damage has retracted his statement. GoPro are considering civil proceedings against him.
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It's actually pretty **** for a big rich company to intimidate journalists and other commentators. Even if they are wrong.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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| dogwatch wrote: |
| It's actually pretty **** for a big rich company to intimidate journalists and other commentators. Even if they are wrong. |
It's pretty poo-poo for a journalist, who should know better than the average member of the public, to make unfounded statements that can materially damage a company's reputation.
Here are his tweets backtracking:
| Quote: |
| STOP ALL SPECULATION. I say I saw Mic Schumacher, I dont say where, I dont say I talk with him or I did an interview with him. Clear ? |
| Quote: |
| STOP ALL SPÉCULATION 2. Mick could not say something about camera or injury of Michael because we did not speak together. |
And one in French:
| Quote: |
| À propos de GoPro, il n'y avait pas d'informations nouvelles. C'était juste mon opinion. |
"Regarding GoPro, there isn't any new information. It's just my opinion"
I've no idea who Moncet is but if it was someone like Piers Morgan or Jeremy Clarkson doing this I doubt anyone would be diving in front of bullets for them.
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What we know is that Moncet has said something that wasn't true. What we don't know is whether that was what he said in the first place or the retraction he made after scary lawyers got to him.
Whichever it was Moncet doesn't smell of roses but I don't think that's very interesting compared to what happens to big companies that attempt to suppress free speech. Anyone remember the McLibel case? It didn't work out wonderfully well for McDonalds even though they largely "won".
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FAQ
