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# Skiiing 50MPH + - Page 6

For those questioning stopping distance, go here.

I put the clip together from one of my many GS videos. The first part of the clip is slowed down about 75% and when the stop begins it slows to almost 90% of the original speed. When that is finished the full speed clip plays to give you an idea of the speed I was going. I was on GS skis, so reasonable GS speeds... somewhere between 30mph and 40mph maybe? The clip starts at the apex of the final turn that I made. One thing to note - watch my stance leg and how much force is being put on it in order to bring myself to a halt. This was taken in early 2006 I think (when I had a torn LCL, which you can clearly see in the clip)... so at the time this was not my strong side to stop on. On my right leg I suspect I could have done it faster.

Later

GREG

If the clip doesn't play until the end, I apologize... I will try to work with it more tomorrow. Putfile is being difficult.
Quote:
 Originally Posted by Lonnie And when I was doing 55-60 mph, I wasn't wearing a helmet....
Why bother?
For the car, 76 ft from 60 mph - if we assume that is from measured from skid marks or some such and therefore does not include reaction time, we get 1.7 seconds at 1.6 g's.

If we put reaction time back, it changes to 1.1 seconds at 2.4 g's.

Those extra 16 feet make a big difference.

I have no problem believing a skier can generate more braking g's than a car. The tires are not digging into the pavement, after all.

Those runaway truck stopping lanes (filled with something soft - sand or small gravel, I suppose) stop a truck going 60 in a lot less than 76 feet.
Quote:
 Originally Posted by BigE If the GPS is reading just horizontal distance in it's calculation, then it would be under-reporting your speed.

GPS uses a Doppler equation to determine Velocity....
Quote:
 Originally Posted by BushwackerinPA natural reaction would be turn around the obstacle so your point in nulll.
Reaction time always matters for an emergency maneuver. Doesn't matter if its a stop or a turn. The distance covered before you react can make or break the outcome.
Quote:
 Originally Posted by Lonnie 1 second.
That is what I figured...so it is infact measuring arm flails....that is one quick pole plant you have!

Another point....I see cars drive down the street all the time, speed limit is 50km/hr or about 30mph....and most cars do about that some abit more, some abit less...but they also seem to be about the average speed of the average skier...not 50mph! I also used to drive alot for work, and spent alot of time on highways, where the speed limit is 90km/h....while stopped on the side of the road, those cars are going by much faster then any skier I have ever seen go by on a run open to the public...

My best guess, is the average skier skis at about 30mph.

I have been clocked in DH courses at around 65mph....and I can tell you, that I have never ever come close to those speeds on an open run as I did in the DH's I have done. Stopping from those speeds is very difficult, the effect that tiny bumps in the run have on your skis is also enourmous....it is obvious from some of the posts from those claiming to ski at 70mph that they were never ever there......
Quote:
 Originally Posted by Skidude72 GPS uses a Doppler equation to determine Velocity....
Straight up GPS doesn't use doppler for anything other than tuning in the satellite carriers.

What individual devices do to display and record velocity data varies greatly.
Gawd, no wonder TGR calls this place gapicski....
Quote:
 Originally Posted by mdf Speed is a funny thing. 30 mph feels really casual. I ski along, pulling my GPS out, adjusting my goggles, pulling up my pants (they are a little too big), or trying to take a picture of the others in my group. 40 mph feels like "pay attention." 45 feels fast. I have a hard time imagining what 70 mph feels like.

I think this post is bang on....it may feel twice as fast, and in reality may take twice the skill.....but that does not mean it is twice the speed.
Quote:
 Originally Posted by Skidude72 That is what I figured...so it is infact measuring arm flails....that is one quick pole plant you have!
Except for the fact that I wasn't flailing my arms, but holding them steady...
Quote:
 Originally Posted by HeluvaSkier For those questioning stopping distance, go here.
Using mdf's numbers, on a 30 degree slope you'll be spreading 4.2 times your weight between your two legs, mostly on the downhill one, in order to meet the figure BWinPA posted.

You can squat 4 times your bodyweight, mostly on your downhill leg? Burly.
Lonnie,

He He...at that speed you would have had your hands out, then done the quick flick so you could see the reading....everytime you flick, the speed goes up, which is when you are looking...then when you put your hand back the speed drops to your actual speed....which was likely no more then 25mph....sorry to be the one to break it to you.
Quote:
 Originally Posted by Skidude72 He He...at that speed you would have had your hands out, then done the quick flick so you could see the reading....everytime you flick, the speed goes up, which is when you are looking...then when you put your hand back the speed drops to your actual speed....which was likely no more then 25mph....sorry to be the one to break it to you.
Have you tried this? Yes or no?

Have you ever seen me ski? Yes or No?

Do you know how fast I free ski? Yes or No?

Until you try it, take your theories and smoke them. Basically, you're full of it and you have NO idea what you are talking about. Sorry, it's the facts. Try walking down the street and moving a gps in your hands. The speed won't change than by more than a few tenths of a mph.

When you do this, you'll see that the "current speed" remains fairly constant it's doesn't move around wildly like you suggest.

I do ALOT of road biking and mountain biking where I record speed (with a variety of devices (3 speedos, 2 gps units). I have a very good idea of how fast 20-25-30-35-40-50+ mph feels. My maximum sustained average on my road bike on flat ground and no wind is around 25 mph (I can maintain that for about 5-10 mins by myself before I pop). My max sprint speed, flat ground, no wind, and solo is around 30-35 mph (I can do that for about 10-15 seconds before I pop). I go WAY faster than that on my skis. WAY FASTER. I have a hill not 2 miles from my house where I can hit 50+ mph on my road bike at will. I have been over that speed on my skis, on a blue run, without a helmet and without a speed suit. I didn't hit anyone, I didn't kill anyone, there weren't even any close calls. Anyone else that is an "expert" skier (able to ski groomed blacks) could do it too. Deal with it.

From my bike speedo...
I have been inspired by this thread. I am contemplating getting a pair of these flyers to practice my two-footed slide technique: http://cgi.ebay.com/06-07-Atomic-Rac...QQcmdZViewItem
If you won't buy BWPA's numbers, how about Ghost's? We are working from actual speed change, so no reaction time in the mix. Then 100 feet --> 2.3 seconds at 1.2 g's.

I think peoples strength in resistance is quite a bit more than their strength in actual extension -- i.e. holding up a weight vs lifting it. That is, squats are not the right comparison.
HeluvaSkier- Thanks it shows a very clear picture of how to stop at speed, successfully.
Hehy Lonie, is that a bike shot or a real shot?
Quote:
 Originally Posted by Snow7 I have been inspired by this thread. I am contemplating getting a pair of these flyers to practice my two-footed slide technique: http://cgi.ebay.com/06-07-Atomic-Rac...QQcmdZViewItem
You don't need anything more than a pair of 165 11M SL skis.
Quote:
 Originally Posted by BigE Hehy Lonie, is that a bike shot or a real shot?
I'm not sure what your asking. It was a shot of my bikes speedo after a ride last summer ('06). It's a sigma 1600 wired speedo. Numbers off the GPS are similar.

Here's a commercial pic of the same device.
Quote:
 Originally Posted by Skidude72 That is what I figured...so it is infact measuring arm flails..........
60 mph=5280 ft/ minute
= 88 ft/second

arm flailed forward will make it 90 feet. or 61.4 mph

a GPS with a second sample rate looks ok to me.

I don't wear carry mine in my hands anyway. And Lonnie doesn't flail.
Quote:
 Originally Posted by Lonnie Have you tried this? Yes or no?
No.

Quote:
 Originally Posted by Lonnie Have you ever seen me ski? Yes or No?
No.
Quote:
 Originally Posted by Lonnie Do you know how fast I free ski? Yes or No?
No.

Quote:
 Originally Posted by Lonnie Until you try it, take your theories and smoke them. Basically, you're full of it and you have NO idea what you are talking about. Sorry, it's the facts. Try walking down the street and moving a gps in your hands. The speed won't change than by more than a few tenths of a mph. When you do this, you'll see that the "current speed" remains fairly constant it's doesn't move around wildly like you suggest. I do ALOT of road biking and mountain biking where I record speed (with a variety of devices (3 speedos, 2 gps units). I have a very good idea of how fast 20-25-30-35-40-50+ mph feels. My maximum sustained average on my road bike on flat ground and no wind is around 25 mph (I can maintain that for about 5-10 mins by myself before I pop). My max sprint speed, flat ground, no wind, and solo is around 30-35 mph (I can do that for about 10-15 seconds before I pop). I go WAY faster than that on my skis. WAY FASTER. I have a hill not 2 miles from my house where I can hit 50+ mph on my road bike at will. I have been over that speed on my skis, on a blue run, without a helmet and without a speed suit. I didn't hit anyone, I didn't kill anyone, there weren't even any close calls. Anyone else that is an "expert" skier (able to ski groomed blacks) could do it too. Deal with it. From my bike speedo...
So I win? I have never seen YOU ski or care....your claim that the AVERAGE skier does those speeds! Can you do them? Sure. Are they possible? Definatley. But to claim that is the AVERAGE speed that the AVERAGE skier skis at is....well by your own admission (bolded above for your convience) is bogus. Deal with it.

:
Quote:
 Originally Posted by Skidude72 But to claim that is the AVERAGE speed that the AVERAGE skier skis at is....well by your own admission (bolded above for your convience) is bogus. Deal with it.
Yes, but when I'm skiing in traffic on groomed blue runs, not passing that many folks and having folks pass me, I can get a pretty good idea of how fast folks around me are going.

BTW, where is your home resort. I think it makes a difference.

For the doubters, I'm bringing these to gathering, so you can see for yourself.
Quote:
 Originally Posted by mdf Just did a quick check on BWPA's braking numbers - they are a little on the heroic side, but not out of the question. Braking from 60 mph to zero in 60 ft including 0.3 sec reaction time means 3/4 of a second of active braking at 3.6 g's. Not unreasonable for a panic situation. I don't know how to estimate the snow physics, but that does not seem out of the question for a well engaged edge crushing and displacing a lot of snow. The balance part (getting low enough not to topple over) would be the hard part.
I wasnt including reaction time, you dont when you measure this sort of things

MDF second post got it right its about 1.6 to 1.7 Gs

to be fair the car in question is really fast.

I cant squat much due to weaker parts of my body 500lb is the most I can do a couple reps on. But juding by what I could leg press which is 1100lb minus what I weigh 190lb. I could peak at around 900lb of force in my legs. About 4.5 times my body weight. Shouldnt take long to be able to slow down assuming i can stay balanced.

Not i am not weight lifter I simply was trying stuff stuff out at my climbing gym.
Quote:
 Originally Posted by mdf I think peoples strength in resistance is quite a bit more than their strength in actual extension -- i.e. holding up a weight vs lifting it. That is, squats are not the right comparison.
You don't stop like a statue. You still need balance and that means flexion and extension of the legs. You also need fine control over the edging. If you are doing this in the real world, as opposed to a place you chose in advance, you also need to deal with defects in the terrain. Remember that at the angles you need to create to do this one leg is deeply flexed. Then there is that nasty little problem of what you've been doing with your legs for the last two minutes...no wonder so many world class racers eat it in the finish corral.

Meanwhile, in "Lonnie feeds the troll" land...
From a peer reviewed journal...

http://www.astm.org/cgi-bin/SoftCart....htm?E+mystore

Quote:
 How Fast Do Winter Sports Participants Travel on Alpine Slopes? Shealy, JE Rochester Institute of Technology, Rochester, NY, USA Ettlinger, CF Vermont Safety Research, Underhill Center, VT, USA Johnson, RJ McClure Musculoskeletal Research Center, University of Vermont College of Medicine, Burlington, VT, USA (Received 16 March 2004; accepted 4 March 2005) JOURNAL JAI Abstract This study was developed to empirically determine the impact of the following variables on the speeds of skiers and snowboarders: activity [skiing versus snowboarding], visibility [clear and sunny sky versus cloudy, overcast conditions], type of resort [day, destination, or combination], and helmets [use or not of helmet]. The study also evaluated differences in speed between males and females and the ability of subjects to estimate their speed. The authors measured the speed of some 650 individuals at three different ski resorts in the U.S. during the winter of 2002/2003. One resort was primarily a destination resort in Utah, one was a day area in New York, and the third resort in Vermont had a combination of destination and day skiers. The speeds were determined by means of a calibrated radar speed gun. Speeds were gathered on consecutive skiers and snowboarders as they were observed from an uphill, looking downhill position. The speed recorded was the highest speed observed during a several second interval while the observed person went through several turns as the skiers and snowboarders moved away from the observer. All observations were made on wide, straight, well-groomed ‘blue square’ (more difficult) trails. The slopes ranged from 16–20° in steepness. The average speed for all observations was 43.0 km/h (26.7 mph), with a standard deviation of 11.2 km/h (7.0 mph). The average speed for skiers of 44.5 km/h (27.6 mph) was significantly higher than that for snowboarders at 38.9 km/h (24.1 mph). The average speed under good visibility of 46.7 km/h (29.0 mph) was significantly higher than for poor visibility conditions at 38.3 km/h (23.7 mph). The average speed for helmet users of 45.8 km/h (28.4 mph) was significantly higher than those not using a helmet at 41.0 km/h (25.4 mph). Males ski and snowboard significantly faster than females. Skiers and snowboarders are fair at estimating their speed (r = 0.56), but they tend to underestimate their speeds the faster they go; for example, at an actual 48 km/h (30 mph), they estimate that they are traveling at 37 km/h (23 mph). The observed speeds are well above the speeds (22.6 km/h, or 14.0 mph) used for ASTM F 2040 helmet testing protocols for recreational snow sports helmets.
I'm not making this stuff up.
Quote:
 Originally Posted by BushwackerinPA I cant squat much due to weaker parts of my body 500lb is the most I can do a couple reps on. But juding by what I could leg press which is 1100lb minus what I weigh 190lb. I could peak at around 900lb of force in my legs. About 4.5 times my body weight. Shouldnt take long to be able to slow down assuming i can stay balanced.
Sorry, doesn't work that way. Did you notice that sled wasn't vertical?

/1100lbs is still a very burly leg press figure.
Quote:
 Originally Posted by Garrett Sorry, doesn't work that way. Did you notice that sled wasn't vertical? /1100lbs is still a very burly leg press figure.
eh mine is on the back straight up...I will try to find picture.....

picture found

IT wouldnt be the full extentsion I could do with something about 3/4 of the weight
Quote:
 Originally Posted by Lonnie From a peer reviewed journal... I'm not making this stuff up.

Yup....about what I expected....in my post #156 I figured 30mph, and this article shows it to be slightly less.
Quote:
 Originally Posted by Skidude72 Yup....about what I expected....in my post #156 I figured 30mph, and this article shows it to be slightly less.
Then what in the world are we aruging about? 5mph?

I said that average int skier skis at about 30-35 mph and advanced skiers are 40-45 on blue groomed slopes....
Quote:
 Originally Posted by BushwackerinPA IT wouldnt be the full extentsion I could do with something about 3/4 of the weight
Damn dude you eat your cereal of champions, no?
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