Can't wait to bump it up

[SkiDork]

I can't wait to get back out there next weekend (16-17) and try to see if I can stay in the Zone I had going in the bumps on Sunday... Yowzers.

Staying tall was the key to my achieving the zone. Hopefully I can recapture that...

 

[Greg]

Do I detect an aspiring bump addict?! A tall stance and quiet upper body is key. I'm a notorious croucher so it's something I struggle with. Good hand position is also important and goes hand-in-hand (pun intended) with a good stacked stance, as is looking down the run. Time to lop a grip's-worth off those poles, Dork...

Where's that pic from?

 

[SkiDork]

Do I detect an aspiring bump addict?! A tall stance and quiet upper body is key. I'm a notorious croucher so it's something I struggle with. Good hand position is also important and goes hand-in-hand (pun intended) with a good stacked stance, as is looking down the run. Time to lop a grip's-worth off those poles, Dork...

Where's that pic from?

I actually ski with very short poles - I'm 6'5" and my poles are only like an inch longer than Ty's, who is 5'1"

I had a longer pair on Sunday, which I proceeded to snap off at the bottom by skiing over them I guess it's back to the shorties...

Also, "hands out front" is another mantra of mine...

 

[2knees]

- I'm 6'5"

that's not making things any easier for you. not that you can do anything about it.

 

[SkiDork]

that's not making things any easier for you. not that you can do anything about it.

see now I've heard that stuff about big people don't do well in the bumps, but I totally disagree.

My legs have a lot more travel in them so theoratically I should be able to absorb BETTER than a shorter person.

 

[Greg]

see now I've heard that stuff about big people don't do well in the bumps, but I totally disagree.

My legs have a lot more travel in them so theoratically I should be able to absorb BETTER than a shorter person.

Interesting point. Yeah, I guess you can get away with absorbing less, but your higher center of gravity probably makes it a wash. The bottom line is any solid groomed trail skier can learn to ski bumps. It just takes a certain level of dedication and a ton of practice.

 

[SkiDork]

Interesting point. Yeah, I guess you can get away with absorbing less, but your higher center of gravity probably makes it a wash. The bottom line is any solid groomed trail skier can learn to ski bumps. It just takes a certain level of dedication and a ton of practice.

yes, and absorption/extension and all it entails is the key to transitioning to bumps from flats./

 

[2knees]

see now I've heard that stuff about big people don't do well in the bumps, but I totally disagree.

nah, not saying tall people cant ski bumps. just saying it isnt making it any easier, more opportunity for things to get out of kilter. I can certainly understand why you say you need to focus on staying tall. Its a tricky thing to do at 5'9, the temptation to crouch at 6'5 must be even more pronounced.

but, if i saw some dude drilling a nice line at your size, i'd sure as hell get out 'da way. natural crowd control for you. no one's gonna get in your line.

 

[SkiDork]

nah, not saying tall people cant ski bumps. just saying it isnt making it any easier, more opportunity for things to get out of kilter. I can certainly understand why you say you need to focus on staying tall. Its a tricky thing to do at 5'9, the temptation to crouch at 6'5 must be even more pronounced.

but, if i saw some dude drilling a nice line at your size, i'd sure as hell get out 'da way. natural crowd control for you. no one's gonna get in your line.

interesting point about things being easier to lose control of because of the height...

Anyway, next time I see you in my line I'll be sure to crash into you

 

[JimG.]

see now I've heard that stuff about big people don't do well in the bumps, but I totally disagree.

My legs have a lot more travel in them so theoratically I should be able to absorb BETTER than a shorter person.

Evan Dybvig, now of Whaleback fame and a former World Cup bumper, is 6'5".

 

[JimG.]

Interesting point. Yeah, I guess you can get away with absorbing less, but your higher center of gravity probably makes it a wash. The bottom line is any solid groomed trail skier can learn to ski bumps. It just takes a certain level of dedication and a ton of practice.

He absorbs as much as a shorter person, but his long legs have more play so he can absorb MORE than a shorter person could.

Totally agree on the center of gravity part; this is the main point that 2knees is making.

 

[andyzee]

Evan Dybvig, now of Whaleback fame and a former World Cup bumper, is 6'5".

One important thing, is he also +280?

 

[Greg]

He absorbs as much as a shorter person, but his long legs have more play so he can absorb MORE than a shorter person could.

I guess my point was that he might get away with only using a portion of his available "absorbtion travel", so-to-speak, while a much shorter skier might have to fully absorb the same bump.

 

[koreshot]

I know this isn't particularly scientific, but my observation has been that outside of racing, majority of successful skiers (bumps, OB, extreme) are on the small to medium side. Not that many 6+ foot 200lbs+ skiers doing bumps. But maybe I just don't know enough about bump skiing.

I would think that as Greg stated, along with the added room for absorbtion comes added height that needs to be balanced, added weight that needs to be supported and the biomechanics would become slower. Isn't quickness and being light on your feet imporant for bump skiing?

 

[JimG.]

I guess my point was that he might get away with only using a portion of his available "absorbtion travel", so-to-speak, while a much shorter skier might have to fully absorb the same bump.

I think we're saying the same thing but coming at it from opposite directions.

 

[jack97]

Being tall should be an advantage in several ways.

In the bumps, you have more range to change the kinetic energy and rotational velocity. Using an analogy of a figure skater when doing a spin; the skater can change the rotational velocity by tucking the arms in or extended the arms out. The center of rotation is the body; by moving the arms out, some mass is away from this center, the velocity is lower. Conversely, when the arms are tucked in, the mass of the arms are closest to the center, thus velocity increases. From the text, the Physics of skiing; Linds shows that the how you move the center of mass with respect to the center of rotation change the kinetic energy and velocity (analogous to the figure skater). BTW he used pumping up to increase speed, the approach is applicable in the bumps. In this case, placing the center of mass away from the rotational center decreases speed.

Now take this to the bumps; the center of the rotation is fixed and is dependent on the curvature of the bump and where. If you look at the figure of ideal bumps below, point A has the center of rotation above the skier and point B has the center of rotation below. So, at point A, absorbing puts you away from the center. While at point B, extending puts you away. Lind shows that the amount of kinetic energy reduced is a ratio of the position of the center of mass to the radius of the rotational center. So, for a fix rotational center, a taller skier has more range to control this.

Another advantage a taller skier has is stability. Again Lind shows the math model of the “invert pendulum”. The physics of how you can balance a broomstick by the tip of the handle. The longer the handle, the more stable you are. Conversely, a shorter handle is harder to balance and less stable. Given that children have their center of mass lower than adults, he uses this model to show that they can easily get into non stable conditions and need to keep the legs further apart or wedge to stay balance. Skiing with the legs closer and making parallel turns put them in an unstable condition. Extending this idea, a taller person has his center of mass higher wrt to the ski thus a longer broom handle, the physic shows a better stability condition.

 

[koreshot]

Being tall should be an advantage in several ways.

In the bumps, you have more range to change the kinetic energy and rotational velocity. Using an analogy of a figure skater when doing a spin; the skater can change the rotational velocity by tucking the arms in or extended the arms out. The center of rotation is the body; by moving the arms out, some mass is away from this center, the velocity is lower. Conversely, when the arms are tucked in, the mass of the arms are closest to the center, thus velocity increases. From the text, the Physics of skiing; Linds shows that the how you move the center of mass with respect to the center of rotation change the kinetic energy and velocity (analogous to the figure skater). BTW he used pumping up to increase speed, the approach is applicable in the bumps. In this case, placing the center of mass away from the rotational center decreases speed.

Now take this to the bumps; the center of the rotation is fixed and is dependent on the curvature of the bump and where. If you look at the figure of ideal bumps below, point A has the center of rotation above the skier and point B has the center of rotation below. So, at point A, absorbing puts you away from the center. While at point B, extending puts you away. Lind shows that the amount of kinetic energy reduced is a ratio of the position of the center of mass to the radius of the rotational center. So, for a fix rotational center, a taller skier has more range to control this.

Another advantage a taller skier has is stability. Again Lind shows the math model of the “invert pendulum”. The physics of how you can balance a broomstick by the tip of the handle. The longer the handle, the more stable you are. Conversely, a shorter handle is harder to balance and less stable. Given that children have their center of mass lower than adults, he uses this model to show that they can easily get into non stable conditions and need to keep the legs further apart or wedge to stay balance. Skiing with the legs closer and making parallel turns put them in an unstable condition. Extending this idea, a taller person has his center of mass higher wrt to the ski thus a longer broom handle, the physic shows a better stability condition.

Not doubting that you have though a lot of your comments thru and on paper I agree with many of them, but how do you explain that in practice most competitive/successful bump skiers are not 6'5" - maybe not as good in the style and air part of the competition?

 

[jack97]

Not doubting that you have though a lot of your comments thru and on paper I agree with many of them, but how do you explain that in practice most competitive/successful bump skiers are not 6'5" - maybe not as good in the style and air part of the competition?

Could be the points needed in air to be a world cup bumper. Most gymnast (that specialized on the floor) and divers are short. But I think its about popularity, a tall kid in america would specialize on a sport where it would be an advatange like basketball and football. IMO bumpers are still taking a back seat compare to the downhill (slalom, gs and sg) events.

But getting back to point, take a look at some of the still shots of world class bumpers, look at how they go into a deep squat while absorbing, they are taking full advantage of range to change the rotational forces.

 

[Marc]

Not doubting that you have though a lot of your comments thru and on paper I agree with many of them, but how do you explain that in practice most competitive/successful bump skiers are not 6'5" - maybe not as good in the style and air part of the competition?

I would say it has more to do with the segment of the general population that is 6'5" or taller. Which is to say, a very, very small percentage.

Consequence does not always imply causation, and there are more factors involved in the making of a world cup bumper than simply favorable physics, which was only puported to have an effect, the importance of which was never really discussed.

 

[jack97]

I would think that as Greg stated, along with the added room for absorbtion comes added height that needs to be balanced, added weight that needs to be supported and the biomechanics would become slower. Isn't quickness and being light on your feet imporant for bump skiing?

Hey Koreshot, I don't mean to be harping on you. Being quick and light on your feet can be one of those myths so common in moguls.

When a wc bumper is ripping down the line he/she is quick and light on the feet. However, I 've seen skiers making the zipperline from a slow to moderate pace. My jaw usually drops when I seem them flow and change their speed while in the zipperline. The trick is that they got the timing right in absorbtion and extension (A&E). In addition, they got this coordinated with the rotary turns. Hang out at the bump fields and look for it, check out the skiers who can will use alot of A&E instead of using quick tail bangs on the bumps. Usually they are the ones who can control the pace anywhere along the line.