 Poster: A snowHead
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Used a Garmin nuvi to measure my max speed whilst skiing.
basically we reset max speed to zero, put garmin in pocket, skied to bottom of piste, checked the max speed obtained
My question is ; can we assume the speed given is accurate, given that we skied down a steepish red run, angle of which, I guess 30-40 degrees, rather than driving along a flat road ?
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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All GPS systems log your position on the surface of the earth using latitude, longitude and altitude. Buy calculating the difference between your position at time A and your position at time B it is possible to calculate your speed between the two points. While this is done in a straight line (albeit in 3 dimensions) the sampling intervals are pretty fast thereby giving you a fairly accurate assessment of speed.
What did it say? I reckon anything above 80kph (about 50mph) is pretty scary!
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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 got 83km and one of the better skiiers in our group got 108k.
After that we put away the Sat Nav ! We had helmets, but we reckoned a fall at 80 or over would prob result in a broken bone.
Must point out no one else on the piste at the time
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Those numbers don't surprise me. I usually wear a wrist-top GPS and that's recorded nearly 80km/hr when I wasn't really trying. I have been much faster - again on a deserted piste - but that was in the days before I owned one.
All a bit frightening when you realise quite how fast you are travelling so I don't intend going there again!
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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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108k sounds a bit unlikely, though not completely impossible if he was taking it straight and in a tuck. It is about the speed of a downhill racer. Most skiers never go over about 40k. I have heard that those things sometimes give odd readings, though.
Anything over about 25º is normally a black run. Anything over 30º will certainly be. The indoor snowdomes are a maximum of 15º at the top - but mostly more like 10º
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We were in tucks and skiing straight down when getting the speed up, reckon if you skied at 80 to 100 upright , would be more dangerous , caus you may be buffeted about by wind
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kendub, Figures are quite plausible... end of last season a group of us were 'clocked' going down one of the reds into Vallandry (Les Arcs) we were all between 89 (me  ) and 100KPH.
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Good topic and can share my similiar experience. We use an anemometer for surfing, just to measure exact wind speeds. Actually not that useful for surfing, vital for kite and wind surfing. Anyway, driving to a surf spot a few months back decided to hold anemoneter out window and speed recorded was pretty much exact speed on car dial. Brought it away skiing with us to measure our speed as it had been something we wanted to do for a long time. Got up to 69.8 km/hr. That was in a tuck going down a steep section of a blue slope. I reckon i could get faster if a) steeper, longer slope, and b) went out first thing when slope has been groomed.
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"could get faster if a) steeper, longer slope, and b) went out first thing when slope has been groomed."
right enuf we went out 1st thing, hadnt snowed for about 14days so hard snow, no bumps whatsoever.
Wonder if you went over a bumpy bit at speed, could one or both boots eject from the binding, frightning thought ? Being recreational skiers, I assume our bindings wouldnt be set ultra tight
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When i came back my goals was to reach over a 100km/hr in my next ski trip in march but after seeing the Micahel Johnson programme on skiing, poo-poo that has made me a bit scared. There are so many things you could hit if you fell. I'd be happy to rach 80 km/hr
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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Would you have a link to the Micahel Johnson programme, please
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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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I did exactly this last year in the Portes Du Soleil. i clocked 47mph whulst using my garmin sat nav and i was flying!!! i was so close to wiping out at the bottom. it was very dangerous and should not really have done it. If you are going to attempt it, please make sure you know the run, and ensure there is nobody else around!!!
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| Ricklovesthepowder wrote: |
| I did exactly this last year in the Portes Du Soleil. i clocked 47mph whulst using my garmin sat nav and i was flying!!! i was so close to wiping out at the bottom. it was very dangerous and should not really have done it. If you are going to attempt it, please make sure you know the run, and ensure there is nobody else around!!! |
Agree, totally. When we were doing this it was first lift on a Saturday morning towards the end of the season in LA. The place was deserted, but pistes were spot on. I wouldn't dream of doing it again - just seeing how fast you can go, I seem to have have lost that 'need for speed' (OK I still go fast on occasion.. but not that fast) , would rather take an hour or whatever getting down somewhere off-piste or a long tricky black. Was damn good fun though!!
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You know it makes sense.
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I hired at GPS in 3 valleys in 2007 where they produced a piste map of where you'd skied based on it, including max speed of 101 kph. Just about made up for one of the gondolas breaking down for 30 minutes with us in it. One with no seats and it was f cold.
And that was 101 kph on . . . pocket rockets.
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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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| allanm wrote: |
| kendub, Figures are quite plausible... end of last season a group of us were 'clocked' going down one of the reds into Vallandry (Les Arcs) we were all between 89 (me ) and 100KPH. |
Clocked by what, by the way? (I'm hoping someone here has a speed not derived from a GPS since I have heard stories of these producing anomalous readings for skiers.) The only similar speeds I have heard of which were measured by piste-side means were ordinary skiers trying out the flying kilometre (though not from the top, of course).
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Poster: A snowHead
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snowball, Speed gun thingy from the side of the piste, similar to coppers use. One of the locals had 'borrowed' it. No reason to believe it wasn't acurate.
Believe you me.. we were flying....
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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just doing some research into my Garmin Edge GPS device, i tend to use it for cycling and have used it over over the recent trip out to France - Paradiski - La Plagne - Montchavin. i have now binned (actually sold) my bandit B2 and now have some Movement Source and clocked 104.5km/h. what i am tryinmg to establish is whether it is accurate; it has a map on the screen, altimeter, speed etc so having spoken to a pal who is an expert with Physics, he says it is realistic using the equation (which is out of my brain factor). so is the device 100% accurate or do the settings need to be changed. it all does seem to stack as when on a lift, typically out of Montchavin it says speed is around 14km/h which is around 8 miles an hour which is twice walking speed so all stacks in my crazy mind. just hoping there is a tecky guy out there! cheers for now 
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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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If you have a garmin, I think you can download to Garmin connect. This is quite good for tracking and gives actual speed graphs etc.
I watched Bormio downhill and those guys were averaging 124km/hr.
Talked to kids race instructor and he said its easy to get high speeds for very short time. My 8yr old son has got up to around 80km/hr, but its a very short time spike.
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I use a garmin GPS V for sailing and dropped it into my back pack a couple of years ago. As it's a garmin I can download it to their "map source" software and look at the actual plots; I have a good one showing a max speed of 72mph which looks valid when looking at the plots; GSP devices may sometimes get spikes if reception is a little dodgy. While sailing and tuning I usually look at "average over 10 seconds" or "average over 100m".... But 100m is not very far at 72mph / 115kph.... It was shussing a very smooth red run...
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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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Took a while but I got 86.4 mph max on Trolles in Tignes. I then stopped trying hard, to not kill myself.
Was just a little handheld GPS thing so accuracy is questionable, but it felt bleedy fast! Was consistently hitting 75 mph down that run on a cold icy March morning.
Downhill racers hit 150 kph on the Hahnenkamm.
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I wouldnt assume that any GPS readout for max. speed or elevation gain is accurate, unless you have an idea of how much datapoint filtering takes place. I'd guess that a Nuvi and those devices that only do max/average speed would have pretty harsh smoothing, to get rid of rogue data (especially shortly after switch-on, etc.), so could be reasonably accurate, especially if a following a straight-ish course at reasonably consistent speed.
But an eTrex (iirc) doesn't filter anything for the on-device stats readout, and if you upload the GPX file to Garmin Connect, Everytrail, Mapmyrun and a handful of other sites, you'll get different results. I'll have to post my MTB GPX file where I managed in excess of mach 1 uphill 
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| snowball wrote: |
| 108k sounds a bit unlikely, though...I have heard that those things sometimes give odd readings, though. |
My Garmin watch gives very odd reading for instantaneous speed and maximum speed. It doesn't take much to throw instantaneous speed into the realms of random numbers. The don't seem to cope well with changes in direction and/or speed in such circumstances. If they lose strength of signal, they apepar to record the last known position and then interpolate to fill in the missing data once the singal strength is restored. I frequently clock maximum running speeds of sub 5 minutes per mile, which would be nice, but isn't true.
Distances and averages are rock solid in terms of reliability, though.
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This thread scares me. People setting themselves goals of how fast they can ski straight down the mountain on publicly-accessible pistes, not about how in control they ski, how fast they can go round turns/gates or what pitch of slope they can ski. If you want to see how fast you can ski go to a resort which offers a go at speed skiing such as Les Arcs or talk to a ski club about doing some Super G/Downhill racing on dedicated closed-off pistes.
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I've calibrated my Holux GPS datalogger and Garmin III GPS gadgets in cars and aircraft and the speeds are generally very accurate, especially in straight lines when straight and level, but the results from skiing seem equally accurate. You do occasionally get the odd strange result if it loses position. But if you do as others suggest above and upload your data to EveryTrail or Snowhead's fishslice fantastic Ski Track App, http://snowheads.com/ski-forum/viewtopic.php?t=42481 you can get rid of any rogue points and smooth it out...
On the lower section of the Lauberhorn downhill course in Wengen is a speed camera with a display, the piste narrows down and you can see there's no one in the way, and your group can ski it one person at a time... I got 85km/hr which seemed pretty fast at the time... but think I could have gone faster if we could have magaged to get back for another go at it or knew what to expect at the bottom...
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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From a safety POV :
One thing we noticed from using a GPS, is how fast one goes without realising it, on a blue, at moderate speed most people do somewhere between 25-45 km, enough to hurt or damage your head without helmet
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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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Indeed!
I've clocked 80kph on mine without really trying. And I know I've been a lot faster than that in the days before I wore a GPS. I've certainly moderated my speed since getting one and realizing quite how dangerous it is.
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Shameless copy of my post on the ski tracks thread, just in case.......
A GPS possibly it helps to motivate some people to ski faster. But generally I have a look at lunch, then again at the end of the day, the rest of the day it stays on my wrist (gps watch) or in my pocket (phone). To go about trying to clock higher speeds you'd probably want a display that you could see all the time, and push to beat it all the time.
The main motivation is to see where I've been, look at the maps and see how I've got on over the longer period. Maybe I'm a wuss, or not sure of my ability yet, and so will always ski well within myself.
I know one thing though, as non helmet wearers (not a conscious decision not to), knowing that we've gone 40mph+ in places was enough for the OH to say "I think we'll get helmets for our next trip".
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You know it makes sense.
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I think something around 80-85kph is a realistic "top speed" for a reasonable skier. My GPS recorded a max speed for the day in this range fairly consistently over 30+ days last year. By that I mean, I noticed that the top speed recorded on any given day only varied by about 2 kph over the season - think it was about 84kph +/- 2kph.
Only exception was top speed recorded one day was 137kph, but that was in very exceptional circumstances
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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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One thing to bear in mind is that GPS use Doppler effect to measure speed (i.e. not distance divided by time).
The accuracy of this does depend on how many satellites you can "see" and of course how many satellites your device can handle. Older 4 channel receivers will tend to give blips especially in mountain and tree conditons at higher speeds. Newer devices with 12 channels or more and fast processors will be accurate within 1mph.
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Poster: A snowHead
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Just remember to turn the voice off!
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Lethal_Hamster, 
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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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Anyone have visions of speed cameras on the slopes and we all have to wear a registration plate on our back..  ..haha dont forget to smile for the cameraaaaaaaa
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You need to Login to know who's really who.
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The maximum speed most downhill racers get to is around 80 mph - about 130 kph, in a crouch, on race skis, on ice.
I have great difficulty believing any recreational skier who says his max speed is much above 65mph/100kph unless it was measured by a proper timed loop or speed trap device. I suspect many are just demonstrating the moment at which their GPS was most inaccurate.
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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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stoatsbrother,
I think the difference with racers is that their average speed is extremely high, ~120-125 kph.
They get that speed very quickly out of the start
These maxes that everyone is talking about are just spikes measured over very short timescale.
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Indeed. I have done this very same exercise with a Garmin Forerunner and believe the speeds to be accurate from the speed vs distance/time graphs I've viewed afterwards along with the map of the run I was on. As gryphea suggests, when I had reached these high speeds I immediately slowed down and didn't maintain the speed for very long.
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gryphea, I'd still like to see some better validated evidence and direct calibration against other speed measuring devices - like that WayneC mentions.
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I remember they had a timing gate at Verbier in the late 80's at the bottom of a steep slope - I think I clocked 85 kph but saw others going over 100kph - last time I tried it I fell on a small bump and went past on my backside and it did not show my speed at all ( came up as 999 iirc......) pity really as I was sure it was a world record for going backwards down the slope on you @rse..... again no crash helmet in those days..... glad I did not hit anything solid
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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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stoatsbrother,
Might be able to help as son will be doing races later in season so I will have times back and gps tracks. Though on a course with turns there must be a tendancy to overestimate speed if the turns are small compared with frequency of gps measurements. I think that can easily explian rogue hgh speed spikes for any skier
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What many people don't appreciate is how quick one accelerates on a steep slope. There are several DH races with very steep starts and at the Womens downhill at Altenmarkt a couple of weeks ago there was a speed gun at the bottom of the start slope which was registering most competitors doing 100kph+ and that was after about 6 seconds. Most cars can't do this.
I've been clocked at Val Thorens in a proper speed trap doing 108 kph and had a GPS register me at similar speds (on deserted slopes, I hasten to add) and whilst it felt fast, having skied about only 40 kph on cross country skis I felt far safer on alpine skis, I can tell you !!
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