The Numbers Game: Bindings, Part 2

[cantunamunch]

I read what Phil wrote as saying the mapping from torque to indicator value shown in the window is not fully specified by the standard.

I think you did get the gist.

I think I understand your surprise now - it's kind of like the surprise some people have at, for example, 30 minute+ 1 lap racing; nowhere is it actually specified how much distance the racers will cover.

 

[Bill Talbot]

I think the use of 'DIN Setting' came about (approx. 1979?) when the binding manufactures switched from a 1-5 type scale representing the minimum to maximum release setting. With no overlap from binding model to different model even within the same manufacturer, let alone the other brands. The new 'DIN/ISO' standard now meant they were directly related to that new standard. Now the indicator window might be 4-10
or 5-12, etc. These were numbers that were 'real' in the sense that they were comparable even brand to brand back to that standard.

So while the term "6 DIN" only relates back to the release force dictated by the new standard, it was a huge leap forward. I expect that
@Rick Howell will chime in here and correct all my inaccurate info, but that is my general take on the change and how the term DIN setting came to be used.

Couple of pix, first a "pre-DIN" Look Toe piece with a 1-5 indicator. Then a "DIN" Look Toe piece with a 4-10 based on the new standard.

And just how Look addressed the setting of that old system Toe piece;

 

[Philpug]

We/you/us/them can call the binding settings a DIN value but in reality it is not. DIN is a standard, there are variations from one binding manufacturer to another, while there are some consistancies...it is not a standard.

 

[Bill Talbot]

We/you/us/them can call the binding settings a DIN value but in reality it is not. DIN is a standard, there are variations from one binding manufacturer to another, while there are some consistancies...it is not a standard.

No, I said it came to be called that as a result of the switch to that new standard. It is a 'setting value' based on the then new standard. There were no standards at all for the settings prior to that although the manufacturer's had their own adjustment recommendations

 

[rj2]

LOL, DIN settings and the metrics behind them have always been kind of a bullshit thing to me. For example, mine says I should be at 6 but I'm here to tell you 6-7 has taken me out prematurely a few times. They always want to dial it down one because of my age too which I found laughable. Anyway, I run all my "recreational skis" at 9 and have found it to be a fair setting. My son has found this to be true as well. The shop set his to 5 when I bought him the new Atomic 95's. He was ejecting all over the face of Killington and getting pissed. Actually dented his helmet pretty good in one premature ejaculation. I went down to the car and dialed them up to 7. He only went down a couple times after that and one time he had an ejection and the other time he didn't. He's been a happy camper ever since. It's hard to ski with confidence and some aggression when you're worried about ejecting all day. Talk about a buzzkill.

He's still young, he'll learn to control his urges. Good thing he had protection.

 

[mdf]

Well, "DIN" is skier shorthand for

ISO 9462:2014, "Alpine ski-bindings -- Requirements and test methods"
ISO 8061:2015, "Alpine ski-bindings — Selection of release torque values"
ISO 9465, "Alpine ski-bindings — Lateral release under impact loading — Test method"

which are standards.

So I am still confused about the point Phil is making. Is it that the torque level is specified but the value on the scale in the window is not?

 

[cantunamunch]

^Don't forget 5355, 9462, 11087, 11088 (insert appropriate update year as needed) ...

 

[Philpug]

Well, "DIN" is skier shorthand for

ISO 9462:2014, "Alpine ski-bindings -- Requirements and test methods"
ISO 8061:2015, "Alpine ski-bindings — Selection of release torque values"
ISO 9465, "Alpine ski-bindings — Lateral release under impact loading — Test method"

which are standards.

So I am still confused about the point Phil is making. Is it that the torque level is specified but the value on the scale in the window is not?

They are methods how to test bindings and specifications...NOT the values that you get in the window.

 

[James]

Well, "DIN" is skier shorthand for

ISO 9462:2014, "Alpine ski-bindings -- Requirements and test methods"
ISO 8061:2015, "Alpine ski-bindings — Selection of release torque values"
ISO 9465, "Alpine ski-bindings — Lateral release under impact loading — Test method"

which are standards.

So I am still confused about the point Phil is making.

I agree. Until notified otherwise, to me , indicator is simply Din value with an allowable error range. Shop uses a torque wrench or test rig to set the actual DIn value on the indicator scale.

Setting the inficator without testing doesn't take in the error range from actual DIN.

 

[James]

They are methods how to test bindings and specifications...NOT the values that you get in the window.

Well what's the allowed error between indicator and DIN?

 

[mdf]

Then where DO the values in the window come from? And why are so similar across brands?

 

[Philpug]

Well what's the allowed error between indicator and DIN?

I will watch what I say here and WILL correct later, when I get a testing book in front of me. (if someone has one, pelase feel free to post it) There is a range, up and down one line. So, if you are an "M", the Nm range of L to N is within range. This is where you could be say an 8, but the window might show a 7 to get it to torque within range.

 

[Philpug]

Then where DO the values in the window come from? And why are so similar across brands?

Again "similar", not the same, there are differences from brand charts to brand charts. IMHO there is the desire to keep it the same, I agree there should be one chart, a standard and the bindings should conform to that chart. Again, as I said in my initial post, I was surprised with this as much as you were. Again, it is just a misused term as "Canting" is on the side of the boot. I don't think was done maliciously it was just easy to do and simple for a layman to understand.

 

[Marker]

I don't believe there is such a thing as "effective BSL". BSL length can't be change by any boot punches. Punching out the toe doesn't change the location of the sole block. Anything that does change the location of the sole block would be unwise (and unsafe) to do to any regular ski boot.

Yeah, I'm not phrasing my concern very well. Can boot toe punches affect the forward pressure enough to require a reset so that the retention forces of the bindings correspond to their indicator settings?

 

[Philpug]

Yeah, I'm not phrasing my concern very well. Can boot toe punches affect the forward pressure enough to require a reset so that the retention forces of the bindings correspond to their indicator settings?

No, because the chassis isn't changing. Now, I have seen to punches interfere with the toe and thus inconsistant release functions.

 

[PisteOff]

I will watch what I say here and WILL correct later, when I get a testing book in front of me. (if someone has one, pelase feel free to post it) There is a range, up and down one line. So, if you are an "M", the Nm range of L to N is within range. This is where you could be say an 8, but the window might show a 7 to get it to torque within range.

This is true. I've had the shop dial them up higher than normal on an older set of bindings because the scale on the binding no longer represented what the machine was torquing the release at when tested. Basically, the spring was weakened over time and what was once a 7 now required an 8.5 on the binding scale to release at the desired value on Hans's machine.

 

[CalG]

Think of it.

A single binding type is mounted for two different skiers that Both are catagorized at a DIN release setting of 7.

One of the skiers has a BSL of 367 mm.
The second has a BSL of 245.

HOW CAN THE BINDING INDICATOR SCALE possibly indicate the DIN release for both at the same indicator position.

It can't!

That's why the skier fills out the information sheet and the test tech applies a separately calibrated measurement tool to accurately evaluate the actual release forces appropriate for each.

In the same way, Friction, spring variations, and wear can cause variations between indicator position, and realized release forces.

DIN actually has nothing to do with the indicators, they could as well be labled with alphabetic symbols.

 

[PisteOff]

Think of it.

A single binding type is mounted for two different skiers that Both are catagorized at a DIN release setting of 7.

One of the skiers has a BSL of 367 mm.
The second has a BSL of 245.

HOW CAN THE BINDING INDICATOR SCALE possibly indicate the DIN release for both at the same indicator position.

It can't!

That's why the skier fills out the information sheet and the test tech applies a separately calibrated measurement tool to accurately evaluate the actual release forces appropriate for each.

In the same way, Friction, spring variations, and wear can cause variations between indicator position, and realized release forces.

DIN actually has nothing to do with the indicators, they could as well be labled with alphabetic symbols.

Agreed. In my case the BSL was within a few mm so the effect was minimal but did figure into it on the machine. I will have to hang out through the whole process and ask some questions this weekend when I get the bindings mounted on the Wailers. I usually just stand back there and suck a beer and shoot the shit or hang out the back door smoking a cigarette. Or I'm out in the store spending more money!

Also of note.....I have one binding (heel piece) that is about a 1/2 or (.25 on the scale) turn different than its mate heel piece on the other ski.

 

[pchewn]

I did some analysis of this DIN chart here: https://www.pugski.com/threads/din-settings.7994/page-2#post-207660

My conclusions are:
1) The DIN settings follow the Boot Sole Length (BSL) linearly within about 4% deviation (as expected).
2) The DIN settings follow the nominal torque values linearly within 2% deviation (as expected).
3) The permissible variation of the torque values for a given DIN setting is +/- 10% (I didn't know what to expect)
4) The nominal release force for the toe can be calculated by F(toe) = 26.8 * DIN + 24.2 (force in Newtons)
5) The nominal release force for the heel can be calculated by F(heel) = 115.3 * DIN + 48.7 (force in Newtons)

 

[pchewn]

Think of it.

A single binding type is mounted for two different skiers that Both are catagorized at a DIN release setting of 7.

One of the skiers has a BSL of 367 mm.
The second has a BSL of 245.

HOW CAN THE BINDING INDICATOR SCALE possibly indicate the DIN release for both at the same indicator position.

It can't!

That's why the skier fills out the information sheet and the test tech applies a separately calibrated measurement tool to accurately evaluate the actual release forces appropriate for each.

In the same way, Friction, spring variations, and wear can cause variations between indicator position, and realized release forces.

DIN actually has nothing to do with the indicators, they could as well be labled with alphabetic symbols.

Well, I have to disagree.
Skier A: BSL=367 Skier code M (based on height, type, weight, age) DIN=7
Skier B: BSL=267 Skier code L (based on height, type, weight, age) DIN=7

A setting of DIN 7 with BSL=367 results in a nominal toe release force of 63.55 N
A setting of DIN 7 with BSL=267 results in a nominal toe release force of 63.55 N

A setting of DIN 7 with BSL=367 results in a nominal toe release torque of 23.3 N-m
A setting of DIN 7 with BSL=267 results in a nominal toe release torque of 16.97 N-m

So the DIN setting is exactly in relation to the release force setting. It becomes a torque through the lever-arm distance of the boot sole length (BSL).

In the case above the skier with the extra-short boot (267), he needs a higher DIN setting due to his shorter boot, and a lower DIN setting because of his skier code.
The skier with the long boot (367), he needs a lower DIN setting due to his longer boot, and a higher DIN setting because of his skier code.

Both need DIN 7, both need 63.55N of release force.