 Poster: A snowHead
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| foxtrotzulu wrote: |
| @jedster, I presume there is also a speed beyond which it is pointless designing a helmet for. You might design a helmet that cna withstand a 50mph impact, but your brain inside will be scrambled so there so there is no point. |
I don't think it's pointless to develop the design, more that the design needs to be rethought. For example in F1 where the helmets were thought to be adding to neck injuries, so 'frontal head restraints' (HANS) were brought in which help to slow down the stopping force. Gradually these are becoming more commonplace, many club racers now use them too.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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@SnoodyMcFlude, You miss my point. I'm saying that helmet should design should progress, but not necessarily in the direction of protecting against straightforward impacts at higher and higher speeds. Instead they should focus on rotational impacts or similar.
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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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| SnoodyMcFlude wrote: |
| pam w wrote: |
| When I was watching the race I cant spell in Kitzbuhel last week some of the world's top skiers were clocking up top speeds of around 100 kph. Makes you wonder about some of these claims. |
I certainly take all the GPS app claims with a pinch of salt. However the men's downhill were approaching 145kph on some bits in Wengen, which is 90mph. |
The speed mentioned on the Hahnekamm was after only a shortish bit of straight path after the Steilhang hence only 70mph. perhaps I will try the same part in a few weeks and see what my tracker says. However, I would not intend to take quite the same speed in to the schuss out of the Steilhang...
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Last year comparing speeds (and being frustrated at "only" 49.5mph - it was on a straight empty path so reasonably safe to test the "speedgun"), a slow guy I had been skiing with said "oh mine says 60mph". Then a couple of moments later "oh - it's on this bus...")
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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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| Pruman wrote: |
| The EN 1077 ski helmet test for CE certification involves dropping helmet from 1.5 metres onto a fixed anvil. I think it replicates something like a 12 mph impact. Pretty useless eh? |
PE= KE, so v = sqrt(2 x g x 1.5) in m/sec = 5.5m/sec = 12.3mph correct
However, try hitting your head against a solid non moving anvil at 12mph. I'd put money on you having more than just a headache. Impact is to do with what you are hitting as well as the speed of impact.
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| Quote: |
However, try hitting your head against a solid non moving anvil at 12mph.
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Ha, no thanks. Even accidently walking into a door frame at a tiny bit over 0 mph hurts like b*ggery.
Tracking speed and trying to outdo your last top speed or beat others, is all very well but I don't think many are equipped physically, have the right ski/binding set up, or adequate protection for if and when it goes Pete Tong at 60mph. I think more resorts should set aside areas with catch netting and proper timers so it can be done away from other piste users frankly.
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I only try to go reasonably fast on straight parts or areas with huge run outs. Not day to day skiing. And hopefully in a proper stable tuck, elbows on knees, not like the usual UK "tuck" of a bent over top body with ski poles pointing skywards.
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@Pruman, I suspect the accident rate would be way too high. Most of the speed guns I have seen were in places designed to stop you reaching too high a speed. I also think 'catch netting' is a bit of a last resort. We've all seen the racers who catch a tip in it on a bend. It's a miracle they aren't torn apart. actually, they sometimes are.
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You'll get to see more forums and be part of the best ski club on the net.
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@foxtrotzulu, well, whatever, resorts need to either (a) pull tickets or (b) give them a place they can "safely" attempt top seed. Thing is, they are doing it anyway but in among other slope users. We've all seen them.
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Using a garmin fenix 2 I hit 97kph coming down the black run from the Tignes glacier at the start of the first week of the season. Only person on the piste at the time and never topped it the rest of the week.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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| Pruman wrote: |
| @foxtrotzulu, well, whatever, resorts need to either (a) pull tickets or (b) give them a place they can "safely" attempt top seed. Thing is, they are doing it anyway but in among other slope users. We've all seen them. |
Even if they introduce option (b), which I doubt, then that won't stop people trying on the piste too. Option (a) might happen, but resorts will be very reluctant unless they consider there is steroids problem. At the moment I'm not convinced there is.
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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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@foxtrotzulu, snipers in the trees?
(a) does happen in the States. I know because mine got the threat of being taken away in Breckenridge. I couldn't have been doing more than 25mph but apparently it was on a slope primarily intended for learners.
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I used to be amongst the quicker skiers on the piste, back in the day of skinny skis.
I am constantly surprised by just what passes me these days and in what degree of uncontrol.
While I know very exactly what 100kph feels like hitting a compression on a pair of DH skis, (having done it under well measured conditions - 100kph is pretty fast and faster than any holiday skier would honestly be able to cope with in urgency) I fear that many people on the slopes grossly underestimate their speed and grossly overestimate their ability to deal with it.
Curmudgeonly codger that I am, accidents waiting to happen.
Oh, no need to wait then...
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You know it makes sense.
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Phone gps - not accurate for speed 😀
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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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| Quote: |
many people on the slopes grossly underestimate their speed and grossly overestimate their ability to deal with it.
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I'm in total agreement. And the 60mph dudes are doing it on their everyday DIN setting. Nothing beats watching an almighty yard sale from a chairlift.
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Poster: A snowHead
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| mooney058 wrote: |
| Phone gps - not accurate for speed 😀 |
What evidence?
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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@Pruman, what's funny is that they're 100% predictable from a quick glance.
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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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| Quote: |
While I know very exactly what 100kph feels like hitting a compression on a pair of DH skis, (having done it under well measured conditions - 100kph is pretty fast and faster than any holiday skier would honestly be able to cope with in urgency) I fear that many people on the slopes grossly underestimate their speed and grossly overestimate their ability to deal with it.
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Last time I skied at Les Grands Montets (which admittedly was a few years ago, will correct that this season) I was amazed at the scenes on the run down to Argentiere. The number of blokes who clearly thought they could ski simply because they were on fat skis but made no attempt to hold an edge while skidding down at mach schnell ... Pathetic
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@jedster, I'm not sure why that's 'pathetic'. Did they ever claim to be brilliant skiers? Maybe they were just having fun skiing the way they were happy to. Would you prefer that people were not permitted to schuss until they have been tested on their ability and 'approved for schussing'? As long as they don't represent excessive danger to anyone else I think they are free to do what they want.
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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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| foxtrotzulu wrote: |
| mooney058 wrote: |
| Phone gps - not accurate for speed 😀 |
What evidence? |
we've got very good evidence from using a mix of phone apps, gps and speed gun, phone aps are all over the place, sometimes 20kph over the top, gps is much better, the thing with a speed gun (Radar like the police) is its THAT speed at That exact time, gps will still be an average over a distance, and apps, well they look good in the bar don't they 
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| Quote: |
As long as they don't represent excessive danger to anyone else I think they are free to do what they want.
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Oh no - they were a danger to other people - that was my point. They simply couldn't stop or take evasive action within a sensible distance. That is what was pathetic. And they weren't schussing exactly more in alternating powerslides
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His helmet came off in that crash!
Was he a danger? Well, just at the point he lost it there was a pylon left and a slow moving and turning skier at 2 o'clock. He could so easily have wiped out that skier. At around 55mph it would have been messy.
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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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@Pruman, looks like it, after a hefty face plant. Yes, he was a danger to himself and others. That's the chamois run which is lovely and wide, very easy to get up speed on, but also very mixed ability. Certainly not a run to be trying a speed run on. By the look on his face at the end I think he might agree.
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@Dr John, they live among us.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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@jedster, yep, pierre a ric, a total nightmare, fortunately one can stay off piste in the crud and bumps much of the way down.
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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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| under a new name wrote: |
| @jedster, yep, pierre a ric, a total nightmare, fortunately one can stay off piste in the crud and bumps much of the way down. |
yeah really busy sundays when people decide they can bomb it on there first day can be "interesting"
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You know it makes sense.
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| iskar wrote: |
| foxtrotzulu wrote: |
| mooney058 wrote: |
| Phone gps - not accurate for speed 😀 |
What evidence? |
we've got very good evidence from using a mix of phone apps, gps and speed gun, phone aps are all over the place, sometimes 20kph over the top, gps is much better, the thing with a speed gun (Radar like the police) is its THAT speed at That exact time, gps will still be an average over a distance, and apps, well they look good in the bar don't they |
A phone app IS using GPS, so I presume you mean a stand-alone GPS set. OK, so we have speed guns that measure a speed at a particular moment in time and that is clearly different from what GPS/phone appas are doing. There will certainly be differences. Both GPS and phone apps are averaging over a distance. 30m in the case of SkiTracks. Presumably this will have the effect of reducing/smoothing any errors and reducing the peak/trough speeds. From a few minutes research it seems as though the accuracy of a phone GPS is at least as good, and frequently better, than most of the consumer grade GPS units (e.g Gartmin eTrex 10). So, if phone apps (as opposed to phone GPS chipsets) are delivering innacurate speeds then I wonder what the reason might be:
1. Deliberately set up to read higher speeds - Seems unlikely and could easily be checked against another independent app like MotionX.
2. There is something about skiing that causes a phone app to over-read. SkiTracks does take into account the vertical component of motion and vertical accuracy of GPS can be poor. This might account for some degree of occasional error but it wouldn't cause an app to consistently over read.
3. The speed guns might be innacurate. I rather doubt that they are calibrated regularly.
Anyway, I'll compare two apps on my iphone with Tomtom and the speedo and we'll see how they differ. I'd expect the speedo to be c.5mph higher.
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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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@Pruman, if he was thinking at all it was about himself, he certainly wasn't looking around him. On evidence presented, it's an open/shut case for having his pass revoked.
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Poster: A snowHead
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@Dr John, the guy he hit is probably still sliding, he disappeared camera left onto the steep part of the run. I can't see any difference between that and ABH/GBH.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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I race as a veteran, including both alpine speed events and (since my previous post) in speedski. My personal best under properly measured conditions (same equipment as used for WC races) now stands at 132km/h. Goal for this season is 150. Training is going well and I have already broken one personal record on a smaller training hill.
Although I have yet to win a serious race and in all likelihood never will, my experience thus far (exceeding 100 on least 50 measured runs) allows me to say that anybody reporting speeds of over 100 in a piste open to the public is one of the following:
A) relying on inaccurate measurements
B) deliberately exaggerating
C) an utter idiot with no concern for other people's safety.
If you want to go that fast, great. But do it in a racetrack. On saturday at training I witnessed a crash where the skier concerned went through the safety netting. We have an exclusion zone behind the netting, so no serious injuries and the safety systems worked. The take home message is that these speeds are serious. It's serious fun too, but hooning around in the open at a speed with a ridiculously long stopping distance is just nonsense.
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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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@hyperkub, +1
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Doing over 100kmh is easy. Just point and tuck. And do one of them mega hockeystops when you get to the flat bit.
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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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@Whitegold, I know the colour of your catsuit.
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@hyperkub well, all 3 points are your opinion only based only on your skiing abilities. Don't think everyone have same abilities as you. Same goes for pretty much everyone else complaining about "idiots who ski fast". Thing is someone who is skiing at 100km/h can be a whole lot less dangerous then someone skiing at 40km/h. It's all about how good they are in skiing  And you don't need to tuck and point straight down to get to 100km/h. Anyone claiming this, should really never try it, as they have no idea about skiing, and will most certainly never ski at that speed safely.
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The primary issue is physics, not skiing ability. The stopping distance of even a great skier at over 100km/h is substantial and the outcome of a crash likely to be very serious indeed.
Naturally there are people better at skiing and boarding than I am. I know several on a personal basis including people with serious merits, like competing at the Olympics and World Cup. They can ski very very fast indeed. But they know better than to go all out in an open piste.
My own competitive merits as a skier are insubstantial by comparison. But I do have sufficient experience of speed events to know what I am talking about. That includes a serious crash on a 80km/h jump in a super-g a few years ago which left me with a tibial plateau fracture, ruptured knee ligaments and a displaced meniscus. Crashing at high speed can hurt a lot.
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"How fast do you think you ski on a piste"
The answer should always be: On an open piste I always ski in a way that is safe for other Skiers, other person and for myself.
Speed is not important - to be in control is important.
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You'll get to see more forums and be part of the best ski club on the net.
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Ski Tracks Accuracy
Following my previous post I did a little non-scientific research. While bowling gently down a quiet motorway we checked four devices against each other at varying speeds. I won't bother to run through all the results so I'll just give the fastest speeds when errors are most likely to show up:
TomTom standalone satnav - 70mph
Car speedometer - 72 mph
MotionX app - 71.1 mph
SkiTracks - 69.6 mph
Obviously not a scientific test, but it does suggest that ST doesn't habitually over-read. If there is an error somewhere, then I haven't fond it yet. It strikes me that people who are complaining about the accuracy of ST have very little to verify the speed against. About the only thing you can compare it to is a speed gun. However, ST and speed guns are measuring different things at different times. ST measures the highest speed at any stage on that run. A laser only measures the speed at a particular moment, which may be nit the fastest you have skied. Comparing ST to standalone satnavs like the eTrex is not very helpful either. I gather most of these devices have the same/lower quality GPS chips and there is no reason they should be any more accurate.
Any other suggestions why ST is inaccurate, IF it is?
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@primoz, well said. My screenshot earlier in this thread was a bit of fun because I've noticed that Ski Tracks does sometimes but up a hugely exaggerated speed. If you close it down and reopen it though, it normally corrects itself. However, I do top out pretty much every day at around 85 km/h when skiing on piste, occasionally over 90 km/h. I'm sick of people making the assumption that I must be out of control or a dangerous idiot. I never tuck anywhere, I am only carving clean lines and I ski in the world's biggest ski area - I know exactly where to go to find a completely empty piste with an ideal gradient and a run out for my kind of fun. I'm also not even close to the fastest people around the 3V's. Some of the club racers who ski the Saulire in Courchevel first thing for fun are unquestionably doing well over 100km/h but they're certainly not out of control.
@foxtrotzulu, that's very interesting. I can tell you from 25 years in the motor industry that car speedometers are deliberately set high so as to protect the manufacturers from being sued by people getting speeding tickets. Same reason why a Police motorway patrol car has to have a calibrated speedometer and you cannot be done for speeding by a normal panda car because they are not calibrated. The stand alone sat navs like Tom Tom are usually very accurate IME so it's good to see that ST is a similar level of accuracy. The satellites are obviously the same for all appliances but I guess the quality of the GPS unit in the particular smartphone might be a variable. It would be interesting to load ST on, for example, an Android phone and an iPhone and see if they record exactly the same speed side-by-side. If they do, that would suggest that the program parameters in ST are better written than the ones in MotionX.
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FAQ
