Physics debate

[Nitram Tocrut]

Hi,

I am just starting this new thread so that the “fights” over physics can be discussed in a specific thread and stop derailing other threads. It is really becoming annoying…

Thank you!

Martin

[GrimSurfer]

This is a noble effort, Martin.

Regrettably, only one side of the discussion was about physics. That side laid out a position and provided a link to a book written by a ski instructor-physicist for a ski instructor association.

The counter arguments have ranged from the laws of physics don’t apply to skiing, gravity doesn’t matter in skiing, and some straw man arguments about cycling.

What’s really happening is that some people are offended by the notion that their views on how a cable binding works might have been wrong.

[snow-mark]

This is very nutritious troll food.

[CwmRaider]

The counter arguments have ranged from the laws of physics don’t apply to skiing, gravity doesn’t matter in skiing, and some straw man arguments about cycling.

Are your above listed "counter arguments" not perfect examples of straw men? Honestly? Or did anyone here actually say those words?

I hope that our next discussions are more about helping each other out.

Have a nice day.

[Nitram Tocrut]

This is a noble effort, Martin.

Regrettably, only one side of the discussion was about physics. That side laid out a position and provided a link to a book written by a ski instructor-physicist for a ski instructor association.

The counter arguments have ranged from the laws of physics don’t apply to skiing, gravity doesn’t matter in skiing, and some straw man arguments about cycling.

What’s really happening is that some people are offended by the notion that their views on how a cable binding works might have been wrong.

@GrimSurfer

If my effort was noble your answer is sarcastic

On your very first reply to my suggestion you are actually derailing the thread…

And to all others, please keep this thread on the line or please continue your discussion through other means

Thank you again!

[GrimSurfer]

It wasn’t intended as sarcasm. It was meant to prepare you for the possibility that your well intentioned suggestion might not have its intended effect.

That’s all.

[GrimSurfer]

The counter arguments have ranged from the laws of physics don’t apply to skiing, gravity doesn’t matter in skiing, and some straw man arguments about cycling.

Are your above listed "counter arguments" not perfect examples of straw men? Honestly? Or did anyone here actually say those words?

Those counter arguments weren’t mine. Yes, you are correct. They were strawmen. Yes, people actually did write those things.

[CwmRaider]

Hi @GrimSurfer
Here is a drawing of a telemark binding. The Rotte ST cable or Voile 3 pin cable admittedly have the binding attachment of the cable closer to the pivot point, but not ON the pivot point.

Do you agree that the distance between the boot heel and the cable mounting point on the ski increases as the boot is lifted?

Do you agree that the spring tension will increase to accommodate the longer distance?

Do you agree then, that this creates a rotational torque to the binding and ski then when the heel is lifted?

Perhaps my terminology is not strictly textbook, as I do not hold a PhD in physics. But then again our forum posts should not be subject to peer review.

[GrimSurfer]

I agree with all those things. Every single one.

The binding, boot and cables are a closed system however. Whatever force the cable exerts on the back of the boot is opposed by an equal and opposite force holding it to the rat trap. (Your diagram appears to show a sliding binding, which is quite different than a standard fixed 3 pin binding with cables that has been the subject of this discussion).

The cable does play a legitimate role as a control element in a standard three pin binding. With it, a skier might be able to shift weight more confidently. This confidence could add speed into the equation. But none of this will affect actual weight transfer because it is still about gravity, skier weight, skier ability, and the duckbill.

[Verskis]

I agree with all those things. Every single one.

The binding, boot and cables are a closed system however. Whatever force the cable exerts on the back of the boot is opposed by an equal and opposite force holding it to the rat trap. (Your diagram appears to show a sliding binding, which is quite different than a standard fixed 3 pin binding with cables that has been the subject of this discussion).

The cable does play a legitimate role as a control element in a standard three pin binding. With it, a skier might be able to shift weight more confidently. This confidence could add speed into the equation. But none of this will affect actual weight transfer because it is still about gravity, skier weight, skier ability, and the duckbill.

I have most of my arguments in the other thread, but the equal and opposite force holding the spring to the rat trap is generating torque on the rat trap. You seem to constantly forget about that part. In a static situation that torque is the same but opposite as the torque generated by the ground and the ski tip. And the torque generated by the skier leg, too. So yes, the forces cancel each other out, so nothing is moving, you are right. But there is now more pressure on the tip of the ski than the rear of the ski. On a TTS binding, this would be impossible without the cables (I mean springs).