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Steals & Deals DIN spinoff thread - Page 2

post #31 of 46
I will start off I'm running on only a few hours sleep and not enough coffee. Coupled with that I'm not an engineer and prefer less complex math. However, here are some observances.

I could be completely misunderstanding what is going on, but from reading what didn't make my head explode in this thread and the link, the layman's version is the tension release setting is the force needed to start the travel and the travel distance is how far it goes while at least at that force before it releases, right?

If that is the case, other than the durability/reliability of better made bindings (i.e. higher DIN range tend to have more metal), why do I care if my setting of 7 is on a 4-10 or a 6-18 as long as the Binding Testing Machine states they both release at 7? Isn't 7 on a big spring 7 on a smaller spring?

When you bring your skis, bindings and boots to a shop to have the bindings tested ON A MACHINE, it tells you at what setting your bindings are releasing. So if I bring my 4-10 set at 7 and my 6-18 set at 7, if everything is working properly, they will both release at 7. All I should care about is whether or not they do indeed release at 7. I shouldn't care which one has the bigger spring but if it is accurately calibrated or not.

Then there is travel. Again, there are different travels and yes I should care what the distance is, but I should NOT blame the release value because of a shorter travel. Something I always thought as odd is that people crank the release value up to compensate for (what I believe is) a shorter travel. How many times have people posted about how a binding sucks and they had to crank it up 2 notches when the real issue very well may have been they went from a (making it up) 35 mm travel to a 20mm travel). There recovery time was shortened and they stating it as premature release and blaming the release tension and not the travel.

Anyway, that's how it sits in my head. Please point out where my thinking might have gone astray, especially if you can do it without hardcore math.

Happy Saturday,
Ken
post #32 of 46
Quote:
Originally Posted by L&AirC View Post

I will start off I'm running on only a few hours sleep and not enough coffee. Coupled with that I'm not an engineer and prefer less complex math. However, here are some observances.

I could be completely misunderstanding what is going on, but from reading what didn't make my head explode in this thread and the link, the layman's version is the tension release setting is the force needed to start the travel and the travel distance is how far it goes while at least at that force before it releases, right?

If that is the case, other than the durability/reliability of better made bindings (i.e. higher DIN range tend to have more metal), why do I care if my setting of 7 is on a 4-10 or a 6-18 as long as the Binding Testing Machine states they both release at 7? Isn't 7 on a big spring 7 on a smaller spring?

When you bring your skis, bindings and boots to a shop to have the bindings tested ON A MACHINE, it tells you at what setting your bindings are releasing. So if I bring my 4-10 set at 7 and my 6-18 set at 7, if everything is working properly, they will both release at 7. All I should care about is whether or not they do indeed release at 7. I shouldn't care which one has the bigger spring but if it is accurately calibrated or not.

Then there is travel. Again, there are different travels and yes I should care what the distance is, but I should NOT blame the release value because of a shorter travel. Something I always thought as odd is that people crank the release value up to compensate for (what I believe is) a shorter travel. How many times have people posted about how a binding sucks and they had to crank it up 2 notches when the real issue very well may have been they went from a (making it up) 35 mm travel to a 20mm travel). There recovery time was shortened and they stating it as premature release and blaming the release tension and not the travel.

Anyway, that's how it sits in my head. Please point out where my thinking might have gone astray, especially if you can do it without hardcore math.

Happy Saturday,
Ken

Increasing the DIN doesn't shorten the elastic travel. People increase the DIN because the forces they generate skiing--not falling--are high enough to release the binding when they don't want it to release, or because they are skiing in terrain where the consequences of a prerelease are high. DIN is always a trade-off. Beginners ski at a lower DIN than experts. That isn't because beginners' bones break more easily. It's because a) they fall more and b) their skiing doesn't generate high forces, unless they fall. When experts set a higher DIN--within the recommended value for a level 3 skier-they accept a higher risk of injury from a fall as the price for not releasing when they don't want to. The skier who sets their bindings even higher than the level 3 or level 4 (one more row down the chart) accepts even higher risk of not releasing when they should. The same is true whether they are using a binding with a low elastic travel or a high elastic travel.

post #33 of 46
Quote:
Originally Posted by oldgoat View Post

Increasing the DIN doesn't shorten the elastic travel. People increase the DIN because the forces they generate skiing--not falling--are high enough to release the binding when they don't want it to release, or because they are skiing in terrain where the consequences of a prerelease are high. DIN is always a trade-off. Beginners ski at a lower DIN than experts. That isn't because beginners' bones break more easily. It's because a) they fall more and b) their skiing doesn't generate high forces, unless they fall. When experts set a higher DIN--within the recommended value for a level 3 skier-they accept a higher risk of injury from a fall as the price for not releasing when they don't want to. The skier who sets their bindings even higher than the level 3 or level 4 (one more row down the chart) accepts even higher risk of not releasing when they should. The same is true whether they are using a binding with a low elastic travel or a high elastic travel.

og,
I understand the risk mitigation the charts suggest and skiers go through. The point in the scenario I tried to explain is not about risk mitigation but how some skiers perceive binding performance. Let me expand on my scenario-

A skier has been using bindings from Acme company for a couple seasons for primarily mogul skiing. His bindings are set at 7. For whatever reason, the skier upgrades his gear and now on a similar ski with bindings from Acme's competitor, Mace company. Still has his bindings set at 7.

In both cases the bindings have passed a Binding test machine at a shop. The problem is when the skier uses the bindings from Mace, he pre releases while skiing in the moguls and has turned the bindings up to 8.5 to make it stop. Nothing has changed with the skier or typical terrain he skis. He is unhappy with the Mace bindings and says they're crap.

The one difference between the Acme and Mace bindings is the travel of the toe piece; Acme is 30mm and Mace is 20mm.

I'm asking in the above hypothetical scenario, are the Mace bindings being turned up because they are crap or because the skier is exceeding the toe piece travel prior to recovering?

Often skiers post here and on other forums stating their new bindings are crap because they have to turn them up and I wonder if the real issue is a shorter travel they have for recovery.

Everything I posted above is made up and I don't even know if the travels I picked are even close, but is does point out difference that usually aren't considered when purchasing bindings.

Ken
Edited by L&AirC - 10/12/14 at 5:56am
post #34 of 46

Oldgoat,

Yes the formula work = force times distance, and the formula for force is distance times k (for a spring in it's elastic range, using 1st order approximation), so to multiply force times distance you have to integrate, which is just like finding the area of a trapezoid with width times height where height changes along the width.  Integrating is just multiplying!  The integrated formula for work is W- 1/2k( (Xf^2 - (Xi)i^2).The final x will be different for the smaller spring and the larger spring, but the difference (xf-xi), i.e. the elastic travel will be the same for both springs.

 

L&Airc,

I think you have it right; a lot of folk compensate for poor binding design by cranking up the DIN.  Personally I think they would be beter off with a better binding.  Qustion is what makes a better binding?  Sure, more work to relase at a given DIN would be better, but what if the achieve that by having a binding that becomes sloppy initially by having less force applied at the very start of the travel, allowing the ski to get a little out of control in the first place where another binding might not cause problems until it really had to?

 

Richard Howel posted a nice graph here in this thread. http://www.epicski.com/t/117938/what-if-kneebindings/180

 

Now, "retention" ( "anti-pre-release" ).  Pls see graph, below:

 

Forward retention ( anti-pre-release ) as a function of release;  binding brands 'A thru F'.

 

Clearly you can get better retention at the same DIN by switcing bindings, but which binding will work better depends on where you set it, AND just because it will require more work to release doesn't mean it won't release more often as allowing it to travel might just set you on the road to disaster in the first place.

post #35 of 46
Quote:
Originally Posted by L&AirC View Post
 
Quote:
Originally Posted by oldgoat View Post

Increasing the DIN doesn't shorten the elastic travel. People increase the DIN because the forces they generate skiing--not falling--are high enough to release the binding when they don't want it to release, or because they are skiing in terrain where the consequences of a prerelease are high. DIN is always a trade-off. Beginners ski at a lower DIN than experts. That isn't because beginners' bones break more easily. It's because a) they fall more and b) their skiing doesn't generate high forces, unless they fall. When experts set a higher DIN--within the recommended value for a level 3 skier-they accept a higher risk of injury from a fall as the price for not releasing when they don't want to. The skier who sets their bindings even higher than the level 3 or level 4 (one more row down the chart) accepts even higher risk of not releasing when they should. The same is true whether they are using a binding with a low elastic travel or a high elastic travel.

og,
I understand the risk mitigation the charts suggest and skiers go through. The point in the scenario I tried to explain is not about risk mitigation but how some skiers perceive binding performance. Let me expand on my scenario-

A skier has been using bindings from Acme company for a couple seasons for primarily mogul skiing. His bindings are set at 7. For whatever reason, the skier upgrades his gear and now on a similar ski with bindings from Acme's competitor, Mace company. Still has his bindings set at 7.

In both cases the bindings have passed a Binding test machine at a shop. The problem is when the skier uses the bindings from Mace, he pre releases while skiing in the moguls and has turned the bindings up to 8.5 to make it stop. Nothing has changed with the skier or typical terrain he skis. He is unhappy with the Mace bindings and says they're crap.

The one difference between the Acme and Mace bindings is the travel of the toe piece; Acme is 30mm and Mace is 20mm.

I'm asking in the above hypothetical scenario, are the Mace bindings being turned up because they are crap or because the skier is exceeding the toe piece travel prior to recovering?

Often skiers post here and on other forums stating their new bindings are crap because they have to turn them up and I wonder if the real issue is a shorter travel they have for recovery.

Everything I posted above is made up and I don't even know if the travels I picked are even close, but is does point out difference that usually aren't considered when purchasing bindings.

Ken

I completely misunderstood what you were saying--thought you were implying that raising the DIN decreases elastic travel and makes retention worse. Re-reading your post I see you said no such thing--you were talking about increasing DIN to compensate for a binding with poor elastic travel, which makes perfect sense (your post, not cranking up the DIN.) I shouldn't post late at night.

post #36 of 46
The older biometric toe markers bindings were notorious for their very limited elastic travel. Apparently Marker felt limited elasticity was a performance benefit. The market felt otherwise.

Probably not a coincidence that Marker started releasing these bindings with DINs higher than anything else on the market (to my knowledge) with bindings that would DIN well into the 20's.

Also worth noting that the new Duke/Squire toe has plenty of elastic travel, and the biometric toe is all but gone. I think Marker has given up on the idea that limited elasticity makes for a more precise binding, or at least that this benefit is more important than overall retention.

I still don't see any reason to think that different springs at the same DIN setting in the same binding will affect elasticity. Yes, spring rates will be different with different springs, but that is different from elasticity, and a seriously doubt that springs rates on that limited amount of travel is going to make any measurable difference in binding performance.
post #37 of 46

The older Biometric toe on the markers made a big difference in how the toe piece released.  Any upward/forward pressure greatly reduced the side release force.  The easiest way to see this is push hard on the biometric piece and push/pull a wing for release.  Easy!  No pressure on the biometric piece and it becomes a lot harder.

 

Once you learned not to sit back and hook in on the toes life was good :D but if you didn't figure this out, bad :eek.

 

If I recall correctly it was to help with the backwards twisting fall during the time were a lot of binding companies started adding some sort of upwards release/influence on the toes.

 

BTW I still have my Marker M48R's and used them for a long time (loved them once I had figured it out by accident).

post #38 of 46
Quote:
Originally Posted by oldschoolskier View Post

 

Once you learned not to sit back and hook in on the toes life was good :D but if you didn't figure this out, bad :eek.

 

And to pre-absorb compressions :D:eek:D

 

Flying so high
trying to remember
How many heel clicks
did I turn the screw?

 

The M46, now, there was a piece of hardware. 

post #39 of 46
Quote:
Originally Posted by cantunamunch View Post
 

 

And to pre-absorb compressions :D:eek:D

 

Flying so high
trying to remember
How many heel clicks
did I turn the screw?

 

The M46, now, there was a piece of hardware. 


Why pre-absorb when you could sit back and jet over them :D at least until the Biometric toe were jetting with them involved learning a new skill of running in ski boots on landing as your skis had jettisoned on take off :eek.

 

Cranking up the bindings to max did help a bit though.

 

Notice binding are mounted on 205's :rolleyes

 

post #40 of 46

My last Biometric Toe binding was a Marker 14.0 Free. http://www.evo.com/outlet/alpine-ski-bindings/marker-comp-14.0-wide-brake.aspx

 

Mounted on a pair of Atomic Sugar Daddies.

 

DIN was set to 10 (level 3 height weight etc) and I had no pre-release problems. But, I wasn't dropping cliffs on them either.

 

I did notice that there was very little lateral elasticity in the binding.  In several binding I have had after this (Salomons and Marker Dukes), I've had some "events" where I saw the toe move way out, but still snapped back into place and retained the ski.  So perhaps some falls in the Biometric toe where skis came off could be considered "pre-releases"- falls in a different binding may not have popped out- but that is muddy territory.

 

Those Marker 14.0's are now on my wife's S7's.  She also has some older markers (I think M48's) on some early 2000's rock ski carvers.  She doesn't ski hard enough for the elasticity issue to be a real problem. I discussed the limited travel with her and she had no issues, so we mounted the 14.0's.

post #41 of 46
Quote:
Originally Posted by anachronism View Post
 

My last Biometric Toe binding was a Marker 14.0 Free. http://www.evo.com/outlet/alpine-ski-bindings/marker-comp-14.0-wide-brake.aspx

 

Mounted on a pair of Atomic Sugar Daddies.

 

I had that exact combo for a long, long time.  

post #42 of 46
Quote:
Originally Posted by cantunamunch View Post
 

 

I had that exact combo for a long, long time. 

 

Was your binding bastardized into the hostage plate? ;)

post #43 of 46
Quote:
Originally Posted by anachronism View Post
 
Quote:
Originally Posted by cantunamunch View Post
 

 

I had that exact combo for a long, long time. 

 

Was your binding bastardized into the hostage plate? ;)

 

No - I had a basement full of Atomic parts at the time, including Variocharger 9mm flat plates.  

 

I did have the goofy elastomeric Marker pads tho.

post #44 of 46
Quote:
Originally Posted by cantunamunch View Post
 

 

No - I had a basement full of Atomic parts at the time, including Variocharger 9mm flat plates.

 

I did have the goofy elastomeric Marker pads tho.

 

Yep, those remain on my wife's skis.

post #45 of 46
Quote:
Originally Posted by oldschoolskier View Post
 

The older Biometric toe on the markers made a big difference in how the toe piece released.  Any upward/forward pressure greatly reduced the side release force.  The easiest way to see this is push hard on the biometric piece and push/pull a wing for release.  Easy!  No pressure on the biometric piece and it becomes a lot harder.

 

Once you learned not to sit back and hook in on the toes life was good :D but if you didn't figure this out, bad :eek.

 

If I recall correctly it was to help with the backwards twisting fall during the time were a lot of binding companies started adding some sort of upwards release/influence on the toes.

 

BTW I still have my Marker M48R's and used them for a long time (loved them once I had figured it out by accident).


I don't make a habit of leaning back, but I can recall one time when I got knocked back upon landing some unexpected air (poor visibility - hit a mogul that I wasn't expecting on Spectacular at Blue Mountain Collingwood doing about a mile a minute) I was waaayyy back - from the knees back, I was horizontal.  I eventually managed to do a situp and pull myself back into position, but I am very glad that I was clamped in with Tryolia 490s  (with the spring that only went to 10, but same housing as the 490 RD) and not a bionic toe piece.

post #46 of 46
Quote:
Originally Posted by Ghost View Post
 


I don't make a habit of leaning back, but I can recall one time when I got knocked back upon landing some unexpected air (poor visibility - hit a mogul that I wasn't expecting on Spectacular at Blue Mountain Collingwood doing about a mile a minute) I was waaayyy back - from the knees back, I was horizontal.  I eventually managed to do a situp and pull myself back into position, but I am very glad that I was clamped in with Tryolia 490s  (with the spring that only went to 10, but same housing as the 490 RD) and not a bionic toe piece.


I went from 360D's to the M48R's what a painful learning curve that was.

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