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# Dan Dipiro's Mogul Book - Page 24

Quote:
Originally Posted by Jamt

I'm curious, what is your view on parametric oscillation in the context of bumps? when would you extend and flex? It is easy to apply to the half-pipe or swing example, but it is not the same as bumps.

The half pipe would be the best analogy, and to get the maximum energy transfer to speed up you need to be short on the way down and tall on the way up.  To slow down you need to be tall on the way down and short on the way up.  The center of mass needs to change at the moment when the largest component of the centrifugal force is aligned with gravity (i.e. bottom).  The change in energy will depend on how much the center of mass can change, how close to the bottom the change happens, and how much angular momentum there is.  If there isn't any angular momentum then there will be no effect.  The centrifugal force must be maintained the entire time the center of mass is changing to get the full effect.  So, in Chuck Martin's example where he "punches the bump", he hasn't had any time to generate centrifugal force in line with gravity, and at that moment of pressure there's very little change in the center of mass.  Most of the compression happens after he releases the pressure therefore there's no more energy transfer while he's compressing.  There are definitely times where bumps are shaped with enough curve to get effects from pumping, but one thing I think about is that speed control with A&E (for typical technique) is not so heavily dependent on the lip of the trough.  If a large part of speed control was from this effect then if the curvature of the bump was largely changed then speed control would fall apart.  But, we don't see that.  Any of these effects that rely on the up hill part of the lip of the trough to work, can't be that important, because we don't see sudden changes in speed control efforts as the size and shape of this lip changes by factors of 2 or 3 or much more.  Therefore, the best skiers at fast speeds actively pull their skis up to avoid their COM moving higher to avoid additional acceleration from gravity, the dominant effect.  Somebody pumping would need to have full force the entire time they are compressing, which also ends up pushing up the COM, so there are competing effects, and with the large variations in bump shape, technique is largely based on avoiding acceleration down steep slopes.

Quote:
Originally Posted by Jamt

I just went back and read some old posts and I see we are on the same page. I haven't read the entire thread but I don't know why you talked about A&E being a minor effect, angular momentum, parametric oscillations etc. Not really necessary IMO.

It all makes sense in the context of the entire thread.  Long on going conversations.

Quote:
Originally Posted by Jamt

I just went back and read some old posts and I see we are on the same page. I haven't read the entire thread but I don't know why you talked about A&E being a minor effect, angular momentum, parametric oscillations etc. Not really necessary IMO.

Just because you may not understand things like parametric and driven oscillation, doesn't make them minor.

Quote:
Originally Posted by Jamt

...

I'm curious, what is your view on parametric oscillation in the context of bumps? when would you extend and flex? It is easy to apply to the half-pipe or swing example, but it is not the same as bumps.

It's easy to apply in bumps, too.  The Engineer is correct in terms of parametric oscillation that the conditions may not ALWAYS exist to use it, but not always is different from seldom.

I am struck that when I first introduced parametric and driven oscillation as terms to the forum a couple years ago, you were one of the posters saying that absorption couldn't control speed, and that the best way to control speed in bumps was to extend into the face of the bump.  This is basic stuff, and bumpers spent the last couple years still using absorption, and bike riders and skaters still pumped for speed.

Quote:
Originally Posted by CTKook

Just because you may not understand things like parametric and driven oscillation, doesn't make them minor.

It's easy to apply in bumps, too.  The Engineer is correct in terms of parametric oscillation that the conditions may not ALWAYS exist to use it, but not always is different from seldom.

I am struck that when I first introduced parametric and driven oscillation as terms to the forum a couple years ago, you were one of the posters saying that absorption couldn't control speed, and that the best way to control speed in bumps was to extend into the face of the bump.  This is basic stuff, and bumpers spent the last couple years still using absorption, and bike riders and skaters still pumped for speed.

I have never said anything along those lines. What I said is that removing pressure on the face of the bump does not control speed.

It seems you are the one that don't understand the physics behind this. You and the engineer are not saying the same thing and don't think you even understand that.

Quote:
Originally Posted by CTKook

Just because you may not understand things like parametric and driven oscillation, doesn't make them minor.

It's easy to apply in bumps, too.  The Engineer is correct in terms of parametric oscillation that the conditions may not ALWAYS exist to use it, but not always is different from seldom.

I am struck that when I first introduced parametric and driven oscillation as terms to the forum a couple years ago, you were one of the posters saying that absorption couldn't control speed, and that the best way to control speed in bumps was to extend into the face of the bump.  This is basic stuff, and bumpers spent the last couple years still using absorption, and bike riders and skaters still pumped for speed.

CTkook, I don't want to get in trouble talking about good technique or right technique from my last post.  I think lots of people are doing different things at different times, and it's all good.  I just keep coming back to the extreme case of world cup speed where they actively pull up their feet which shows dominant effects at large speeds.

Quote:
Originally Posted by Jamt

I have never said anything along those lines. What I said is that removing pressure on the face of the bump does not control speed.

It seems you are the one that don't understand the physics behind this. You and the engineer are not saying the same thing and don't think you even understand that.

It seems to me that he understands, but feels there are many times he likes to pump to control speed in certain bumps, whether the world cupers are doing it or not.  Right, CTkook?

Quote:
Originally Posted by The Engineer

It seems to me that he understands, but feels there are many times he likes to pump to control speed in certain bumps, whether the world cupers are doing it or not.  Right, CTkook?

I think the whole reference to pumping to control speed is a very unfortunate thing, introduced by BTS and Jamt among others.

It is to be blunt even potentially dangerous, as someone reading this who took it seriously could go out, think "I need to pump to control speed" and launch themselves.

It is also an inversion of reality.  In the real world, skiers, skaters, and bike riders all pump FOR speed.  They absorb to slow down.  Just as kids pump a swingset and can also kill speed in the swingset by reversing the movements.

When a forum like this one has posters pitching an inversion of reality -- in this case, pump the face to slow down, which is not the way it works, though there are continual doozies on here, my favorite being skiing as an almost wholly anaerobic sport -- it is good to ask why.  In many cases it is because the posters ain't been there.

The active participants in the sport speak of absorption for roughly 50% of  speed control.  For purposes of a technical discussion, anti-pump is certainly also a good way to phrase it, but for purposes of communicating the movements involved, we should stay with the language of the sport.

For world cuppers, yes, it is valid to look at film and discuss, for them, exactly how much of speed control comes from X or Y.  It is valid to do this for good recreational bumpers too; it's been done for swingsets and is interesting (most people use more driven oscillation than parametric to power the swing, but those who go bigger seem to go the other way).  I enjoyed your analysis of the Mosley video, and think it could be fun to figure out what geometry is most conducive to pumping for speed on skis or for absorbing for speed control, and then simply go out and look at a range of bump runs and quantify how good the fit is for parametric and/or driven oscillation on nasty tight bumps, big lovely bumps, etc.  That's not been done and probably should be done by someone.   The "roughly 50%" was never intended to be precise, and it would helpful to know if it's 75 or 50 or 10 and if those percentages vary dramatically from bump run to bump run.   That doesn't mean changing a practical and helpful vocabulary that has been with the sport for some time is  a good thing, nor that denying an important part of technique is a good thing.

Nor, for that matter, is it good to confuse readers here about what happens if they DO pump on, say, a bike this summer.  Here's what happens:  they speed up.  They don't slow down.

Quote:
Originally Posted by CTKook

anti-pump is certainly also a good way to phrase it,

I thought of using "anti-pump" too to describe it for this forum.  Around my office, we just call it all pumping, but then specify the phase, so speeding up would be pumping with 0 degree phase, anti-pumping or slowing down would be pumping with 180 degree phase, and then of course you could have any phase in between for partial effect which corresponds to bad timing in the skater example.  The amplitude and action of the pumping is the same, it's just how it's timed with the half frequency that controls the result.

I am being quoted so I must respond. Where did I tell anyone to pump to control speed kook? That's a blatant misrepresentation. Perhaps you still don't understand the discussion.

The problem you are having is that you still don't understand correctly WHY flexing your legs at certain times in a half pipe can contribute to slowing you down. Your misunderstanding on this point leads you to false conclusions about the nuances of how to ski bumps well. Numerous people have tried to explain this to you, but you are not listening.

We've been through this a ton already, aside from the mild amusement of watching TE thrash around as the new guy here, are we getting anywhere with this? Not really...

(Asking for understanding, not to implicate or impugn)

When I see a snowboarder come back into a half-pipe, they generally flex / get shorter, and typically tilt their board to the uphill end of the pipe - they want speed for the next wall (and want to preserve length of the pipe)  They also do this when they first enter the pipe.

I would say this is pumping, and is used to increase speed.

The skier cross guys do the same thing on the early rollers in a ski cross.

However, if the have screwed up their run and want to just barely back

make it up the next wall, they will soften their legs as they go up, and stall just above the lip.

Visually, the moves look similar (flexed position, with one going down the wall the other up).

Q1)   Do I have this right?

Q2)   What is the physics of each of these?

Thanks

Doc. When you flex you reduce pressure. That's it.

Now think through how reducing pressure at different situations would cause you to speed up or slow down. It has a lot to do with gravity and reaction forces
Quote:

(Asking for understanding, not to implicate or impugn)

When I see a snowboarder come back into a half-pipe, they generally flex / get shorter, and typically tilt their board to the uphill end of the pipe - they want speed for the next wall (and want to preserve length of the pipe)  They also do this when they first enter the pipe.

I would say this is pumping, and is used to increase speed.

The skier cross guys do the same thing on the early rollers in a ski cross.

However, if the have screwed up their run and want to just barely back

make it up the next wall, they will soften their legs as they go up, and stall just above the lip.

Visually, the moves look similar (flexed position, with one going down the wall the other up).

Q1)   Do I have this right?

Q2)   What is the physics of each of these?

Thanks

Will a response to this be considered thrashing?  I think it's a little bit more than mild amusement.  I think we're approaching full on entertainment.

Quote:
Originally Posted by borntoski683

I am being quoted so I must respond. Where did I tell anyone to pump to control speed kook? That's a blatant misrepresentation. ...

Perhaps here?:

Quote:
Originally Posted by borntoski683

OMG here we go again.  You don't absorb speed.  You pump to slow down!!!  ...[emphasis added]

Only a few days ago.

There is blatant misrepresentation going on BTS, aka Dewdman (you had thousands of posts as Dewdman, correct, before launching BTS as an identity?) and ain't from me.

Quote:
Originally Posted by The Engineer

Will a response to this be considered thrashing?  I think it's a little bit more than mild amusement.  I think we're approaching full on entertainment.

@The Engineer

I haven't thrashed anyone, nor questioned anyone's understanding.  If you have a problem with others on this thread, I don't think you should direct it at me.

Quote:
Originally Posted by borntoski683

Doc. When you flex you reduce pressure. That's it.

Now think through how reducing pressure at different situations would cause you to speed up or slow down. It has a lot to do with gravity and reaction forces

At the top of the half pipe when you compress there's no change in pressure, because you are already weightless, but yet essential for speed control with parametric pumping, so I don't think that will answer Doc's question.  Am I still thrashing?  Stop making me do that.

Quote:

(Asking for understanding, not to implicate or impugn)

When I see a snowboarder come back into a half-pipe, they generally flex / get shorter, and typically tilt their board to the uphill end of the pipe - they want speed for the next wall (and want to preserve length of the pipe)  They also do this when they first enter the pipe.

I would say this is pumping, and is used to increase speed.

The skier cross guys do the same thing on the early rollers in a ski cross.

However, if the have screwed up their run and want to just barely back

make it up the next wall, they will soften their legs as they go up, and stall just above the lip.

Visually, the moves look similar (flexed position, with one going down the wall the other up).

Q1)   Do I have this right?

Q2)   What is the physics of each of these?

Thanks

This is one example of how you could pump speed:

The boarder drops in flexed at A

At B he extends and is fully extended at C. This does not change the speed but the COM has risen.

The speed is enough to get him to D, which is higher than A with the same amount he rose the CoM between B and C.

When he drops down again the speed will have increased (He would have bent his legs again just before D but that is not shown in the figure.

If you follow the opposite pattern from D to A the speed will slow.

Notice also, that the speed has increased without pumping against a curved surface, contrary to what some here has claimed.

This has very little to do with conservation of angular momentum by the way. For that to work the forces involved has to pass through a fixed point. That only happens twice per oscillation.

Quote:

@The Engineer

I haven't thrashed anyone, nor questioned anyone's understanding.  If you have a problem with others on this thread, I don't think you should direct it at me.

My fault.  I should have included Borntoski's quote in there.  I was responding to Borntoski.  That's twice I've sent more angst your way than I meant.

Ok kook you win I used the word pump somewhere in response to you, but you are taking it out of context and misrepresenting thousands of words I have written on this thread. msybe you should clarify what you mean by the word pumping and what you think I meant in that post? What I have been clear about throughout this thread is they we should flex on the face of a bump, not extend. But PRESSURE is what slows us down. If you mitigate your flexing so that some pressure is retained in order to slow down, is that pumping in your view?

As usual you are just trying to pick fights and quoting people out of context, not to seek understanding but rather to discredit through misreprentation. You tangle in word games with people and if they slip up using your language in response you come back with quotes out of context, ignoring the rest. That is intellectual dishonesty.
TE my comment about you thrashing was how you are trying to reason with kook on this particular topic which he has spent the last few summers evangelizing about pump tracks and imaginary speed soakers in our legs
Quote:
Originally Posted by Jamt

This is one example of how you could pump speed:

The boarder drops in flexed at A

At B he extends and is fully extended at C. This does not change the speed but the COM has risen.

The speed is enough to get him to D, which is higher than A with the same amount he rose the CoM between B and C.

When he drops down again the speed will have increased (He would have bent his legs again just before D but that is not shown in the figure.

If you follow the opposite pattern from D to A the speed will slow.

Notice also, that the speed has increased without pumping against a curved surface, contrary to what some here has claimed.

This has very little to do with conservation of angular momentum by the way. For that to work the forces involved has to pass through a fixed point. That only happens twice per oscillation.

You can't have a flat spot at the bottom to put energy in, because you have to push against the centripetal force to get force and distance =work.  Ignoring the drop, let's just say you're approaching C with a velocity.  There's no record of how you got that velocity, did someone push you, did you drop through a curve, did you use a rocket.  Regardless, you have a velocity, which gives you your kinetic energy.  That energy is only based on mass and velocity.  It has nothing to do with whether you are standing or squatting.  You can stand and squat as much as you want and it will not change your speed.  By conservation of energy, that energy must be given up to potential energy only (mass, gravity, height)  (in a frictionless world), so the height you will achieve has to be the same no matter whether you stand or squat.  So, to increase the amplitude of the swings you have to put in more energy by using your legs to push against the centripetal force which will be greatest at maximum speed at the bottom of a curved surface.

Quote:
Originally Posted by Jamt

This is one example of how you could pump speed:

The boarder drops in flexed at A

At B he extends and is fully extended at C. This does not change the speed but the COM has risen.

The speed is enough to get him to D, which is higher than A with the same amount he rose the CoM between B and C.

When he drops down again the speed will have increased (He would have bent his legs again just before D but that is not shown in the figure.

If you follow the opposite pattern from D to A the speed will slow.

Notice also, that the speed has increased without pumping against a curved surface, contrary to what some here has claimed.

This has very little to do with conservation of angular momentum by the way. For that to work the forces involved has to pass through a fixed point. That only happens twice per oscillation.

Thanks Jamt

I asked about the slowing to stall at the top of the pipe because I see that as analogous to the front-side of the moguls:

The momentum of the skier and the terrain are not aligned:  something has to give:

If the skier goes in tall and stays tall (or rigid in general)  --> he gets air.  This is desirable at the two jumps but typically not in the moguls.

The more the skier flexes, the more he may slow his COM before it crests the mogul

At least that's how I think about the frontside - like the pause on the stairs as I go down smoothly...

Quote:
Originally Posted by The Engineer

You can't have a flat spot at the bottom to put energy in, because you have to push against the centripetal force to get force and distance =work.  Ignoring the drop, let's just say you're approaching C with a velocity.  There's no record of how you got that velocity, did someone push you, did you drop through a curve, did you use a rocket.  Regardless, you have a velocity, which gives you your kinetic energy.  That energy is only based on mass and velocity.  It has nothing to do with whether you are standing or squatting.  You can stand and squat as much as you want and it will not change your speed.  By conservation of energy, that energy must be given up to potential energy only (mass, gravity, height)  (in a frictionless world), so the height you will achieve has to be the same no matter whether you stand or squat.  So, to increase the amplitude of the swings you have to put in more energy by using your legs to push against the centripetal force which will be greatest at maximum speed at the bottom of a curved surface.

No that is not it. The reason why all swing examples have you push at the bottom and use conservation of energy as a computational tool is that it is the only place where all forces go through the same point. At all other places the gravity force does not pass through the center of rotation.

In my example the speed at B is given by v^2/2=g*h. where h is the height.

The speed is still v by C, and by using the same expression the height at D is h+the rise height. You have added energy.

You don't have to work against the centripetal force. It is enough with gravity. Sure you could get even more speed if there was not flat part, but it is not necessary.

It is much easier to consider how much energy you add than to consider angular momentum etc.

Quote:
Originally Posted by borntoski683

TE my comment about you thrashing was how you are trying to reason with kook on this particular topic which he has spent the last few summers evangelizing about pump tracks and imaginary speed soakers in our legs

My feeling is that CTKook wanted acknowledgement of the physical reality of parametric pumping and consideration of it's role in mogul skiing.  When you say I'm thrashing around without making any progress, it makes me feel that I'm wasting everyone's time.  If you don't take the time to think about the physics and come to conclusions that have real world consequences, then it is a waste of time, and for many that's true, but I hope it's not a waste of time for those that needed a little extra consideration to answer some plaguing questions about A&E.  For me I solve problems like these regularly that have real world consequences if I get it wrong, and money in my pocket if I get it right, so I spend the time to fully understand any problem and be as correct as possible.  I put allot of thought into anything I say, and I would like everyone else to give lots of thought before jumping to the conclusion that I'm wrong.  For allot of this stuff, to me it feels as if I'm saying something like "4/2=2", and then someone will reply, "You're wrong!  Because, 2+2=5".  If you haven't been through a PH.D program in physics, and you think I'm wrong about physics, most likely it's not me.  Everyone can make a mistake, so please discuss with me, but it's very frustrating to keep hearing that 2+2=5 with such authority.

Edit: I see there's a bunch of replies i hadn't seen on mobile when I posted.

Docbrad, flexing at the lip has more to do with not getting kicked out so that one drops way down and lands down in the tranny or worse. Now maybe those really going for it are combining pumping? A real pipe, a superpipe, which is now pretty rare is 22 ft to the floor. Just being up at the top is pretty scary. Getting kicked out and dropping 15 ft, landing off balance is not something one wants to do. Even a 16 footer is big way down.

It's interesting how some just will not go in a pipe. I'm talking kids who are throwing back flips off jumps in the park. Several I knew this year would not do the pipe because they don't want to come down and hit the lip and get hurt or land down on the floor. (They also weren't doing moguls.)
Quote:
Originally Posted by The Engineer

Quote:

I asked "what am I missing"  so I don't really understand where your reply is coming from...

Most of that was aimed at Tog who doesn't seem to pass up any opportunity to give me a jab, well thought out or not.

Yes, basically true. The last was beyond the pale, sorry. Frustrated here as I should be heading to Abasin but will not be this year.

The comment also had nothing to do with the physics but the video. I'm not qualified to argue with you on that. (There are at least two people in this discussion with phd's in physics and I don't know CTK's background in that area.) The word analysis was used in relation to movement in the video not physics.

Thrashing? Heh, well you're doing ok. Many of these discussions become thrashing. You should stick around. My jabs started over the portrayal of the state of attitudes towards moguls and mogul skiers. I still think it's out of date and the book suffers because of it yet that's the marketing position from the title. It's an ok but pretty incomplete book. A and E isn't really detailed. The link docbrad posted to the 50 page primer for bumpbusters has the makings of a much better and more complete one.

So question, why was parametric oscillation considered if it requires movement around a constant radius? Or was it the cyclical nature of the zipperline? Seems like none of the bumpa are regular nor have a constant radius on the upslope.
Quote:

Quote:
Originally Posted by Tog

Ok, so he's blasting the moguls with the tips and letting them absorb some of the impact. That requires commiting to the line and a certain speed- fast.

What else was suggested to get to that point?
The usual suspects:  hands in front, eyes 2-5 moguls down the line, hips stay directly down the hills, turning as well as A">@borntoski683
where he talked about touch and pressure.  For me personally (and in the right bumps / pitch / etc)
I sometimes need to remind myself to take a very direct line, which, as you noted, requires commitment to speed.  I found this usually only happens (for me)
on blue terrain and/or spring slush bumps or filled in bumps (ie powder day bumps)

Thanks for the link. That'a got some great stuff in it and I've only just skimmed it. He should do a book.
Quote:
Originally Posted by Jamt

No that is not it. The reason why all swing examples have you push at the bottom and use conservation of energy as a computational tool is that it is the only place where all forces go through the same point. At all other places the gravity force does not pass through the center of rotation.

In my example the speed at B is given by v^2/2=g*h. where h is the height.

The speed is still v by C, and by using the same expression the height at D is h+the rise height. You have added energy.

You don't have to work against the centripetal force. It is enough with gravity. Sure you could get even more speed if there was not flat part, but it is not necessary.

It is much easier to consider how much energy you add than to consider angular momentum etc.

Let's say you are 150 pounds traveling at 10 miles per hour while standing.  What's your kinetic energy?  Now, you are 150 pounds traveling at 10 miles per hour while squatting.  What's your kinetic energy?  The Standing or squatting while traveling in a direction perpendicular to gravity will not allow gravity to have any effect on your speed, therefore your kinetic energy is the same.  When you stand you increase your potential energy, just by that small amount, so you may end up just that much higher at the top of the half pipe, but then you have to squat again at the top to continue the pumping cycle and you give up that energy right back with no net gain.

Quote:

Thanks Jamt

I asked about the slowing to stall at the top of the pipe because I see that as analogous to the front-side of the moguls:

The momentum of the skier and the terrain are not aligned:  something has to give:

If the skier goes in tall and stays tall (or rigid in general)  --> he gets air.  This is desirable at the two jumps but typically not in the moguls.

The more the skier flexes, the more he may slow his COM before it crests the mogul

At least that's how I think about the frontside - like the pause on the stairs as I go down smoothly...

So first let's not conflate two issues.  Getting air does not mean speeding up.  Getting air simply means the path of movement deviated away from the slope.

Likewise, not getting air does not equate to slowing down.  It simply means you did not redirect your path of motion away from the surface of the snow.

Just like carved turns lose little speed, the same can be said for hitting a nicely curved jump face.  Speed is efficiently redirected in a new direction away from the surface of the snow.  Once you start moving away from gravity though, gravity will start decelerating you.

Quote:
Originally Posted by The Engineer

Let's say you are 150 pounds traveling at 10 miles per hour while standing.  What's your kinetic energy?  Now, you are 150 pounds traveling at 10 miles per hour while squatting.  What's your kinetic energy?  The Standing or squatting while traveling in a direction perpendicular to gravity will not allow gravity to have any effect on your speed, therefore your kinetic energy is the same.  When you stand you increase your potential energy, just by that small amount, so you may end up just that much higher at the top of the half pipe, but then you have to squat again at the top to continue the pumping cycle and you give up that energy right back with no net gain.

As long as the pressure is less when I squat than when I extend I still get a net gain. Same is true for the case with a curved bottom. Its just that the difference can be larger.

Quote:

Thanks Jamt

I asked about the slowing to stall at the top of the pipe because I see that as analogous to the front-side of the moguls:

The momentum of the skier and the terrain are not aligned:  something has to give:

If the skier goes in tall and stays tall (or rigid in general)  --> he gets air.  This is desirable at the two jumps but typically not in the moguls.

The more the skier flexes, the more he may slow his COM before it crests the mogul

At least that's how I think about the frontside - like the pause on the stairs as I go down smoothly...

The only problem is, what you think is helpful is not correct.  It would be helpful if people learned this stuff before engaging in misdirection on here.

Quote:
Originally Posted by Jamt

This is one example of how you could pump speed:

The boarder drops in flexed at A

At B he extends and is fully extended at C. This does not change the speed but the COM has risen.

The speed is enough to get him to D, which is higher than A with the same amount he rose the CoM between B and C.

When he drops down again the speed will have increased (He would have bent his legs again just before D but that is not shown in the figure.

If you follow the opposite pattern from D to A the speed will slow.

Notice also, that the speed has increased without pumping against a curved surface, contrary to what some here has claimed.

This has very little to do with conservation of angular momentum by the way. For that to work the forces involved has to pass through a fixed point. That only happens twice per oscillation.

This helpfully illustrates that you and BTS don't have an idea how this works.  Among other things, if this was the way it worked, you'd invalidate hundreds of millions of dollars in built and rideable skateparks and bikeparks -- but those parks are there and imminently rideable and pumpable.

Quote:
Originally Posted by borntoski683

Ok kook you win I used the word pump somewhere in response to you, but you are taking it out of context and misrepresenting thousands of words I have written on this thread...

It's not out of context at all.  This is also a consistent pattern of posting behavior by you.  In a prior thread on the same topic, you even tried to deny that a video that said 50% of speed control came from absorption, said that.  Maybe you are easily confused, and certainly these things happen Dewdman, but when it happens all the time it is reasonable to point out.

In this case, you said that one pumps to slow down, in a context prone at best to cause great confusion.  Then you denied having said it.  It is what it is.

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