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Binding forward pressure - how much?

post #1 of 28
Thread Starter 
Does anyone know the approximate amount of forward pressure used in bindings (ie, in pounds or newtons) or the spring rate (ie, pounds force per inch of travel or equivalent).

I did a search and found plenty of references to setting the forward pressure, but these were always based on looking at the indicator mark, not an actual value.

TIA,

Tom / PM
post #2 of 28
PM,
Not sure if this is what you're looking for...
DIN & release chart
post #3 of 28
Thread Starter 
Thanks Fox, but that table only gives the 2 release settings (in real units), but unfortunately, not the forward pressure setting that I am looking for.

Tom / PM
post #4 of 28
Sorry, if I'd realised it was a race against the maggots, I would have stripped down a binding immediately.
The answer I got for a Salomon 810 at 26C, 998mmHg and 30% humidity was 95.473lb, approx.



S
post #5 of 28
Thread Starter 
> Sorry, if I'd realised it was a race against the maggots, I would have stripped down a binding immediately...

Now that's the spirit, old boy! Hop to it & you won't be letting young folks pass you by on such important matters.

Actually, I was fairly amused that maggots (who are sometimes maligned for their lack of technical expertise) picked right up on my question.

Tom / PM
post #6 of 28
You win..I bit..go fish..
I had to break out my Mitutoyo mic's from my machinist days
HEHEHAH..I placed a bathroom scale on my stolen road sign(THICK galvanised) that I use to make plates(ski/binding) out of.
The only pair of skiis that were handy..I weighed them.Then I pressed the heel piece down as I reweighed at the beginning and end of the travel..

Beginning of travel..20 lbs forward force..
End of travel........80 lbs forward force..

You brought up a very good point..Sometimes it is these springs that go weak..and are pretty much not accessible to replace.I just know that when they are too easy to step into..they're finished.

There is a bit on this at the Vermont Ski Safety site..regarding inadvertant forward releases(phantom)that are caused by just this..I don't recall them getting into specifics..just that an awful lot of skiers tighten the releases thinking this is the problem..
post #7 of 28
Thread Starter 
Excellent. Thank you very much for the measurement. I like the way you did it.

BTW, the reason I wanted an independent estimate of this number doesn't have anything to do with fatigue issues. Rather, its that I don't believe all the hype that "integrated binding systems" significantly change the under-foot stiffness of skis. I think this particular effect is quite small and that people are really feeling other effects of these binding systems. I've done some measurements and also wanted to do some calculations to back up my conclusions. Stay tuned.

Tom / PM

PS - A: You mentioned that you had a micrometer but you didn't say how much travel it took to go from 20 to 80 lbs. By any chance, did you happen to measure this as well?

[ August 24, 2003, 11:19 PM: Message edited by: PhysicsMan ]
post #8 of 28
Quote:
Originally posted by PhysicsMan:
I don't believe all the hype that "integrated binding systems" significantly change the under-foot stiffness of skis. I think this particular effect is quite small and that people are really feeling other effects of these binding systems.
PM:

I agree with you in this assessment. Personally I think each manufacturer gives you a diferent "benefit" from their integrated binding system. FWIW, I like to think of the "benefits" more along the line of design changes.

In the case of Salomon's Pilot I believe the benefit is the removal of the traditional mounting plate in the ski which does in fact significantly increase the underfoot flexibility of the ski.

In the case of Volkl's Motion system I have alot more trouble understanding the design change. In the first iteration of the motion plate onto which you could mount any binding the benefit was that you could change the area the binding apploied pressure to the ski by moving the pin holding the plate to the ski. In some of the current iterations with plastic rails and no plate I see the system allowing alot more flex in the roll coupling and not allowing more underfoot flex since they still have the mounting plate in place. In the newer "Double Edge" metal rail iterations I see a system that applies more pressure to the front of the ski. In Piston Motion I find a system that removes the rebound from the ski.

Dynastar's Auto Drive (while not an integrated binding system but a "binding interface system" - my naming in quotes) is very successful in allowing more longitudinal flex from the middle of the ski through the tail while increasing torsional rigidity in the same area. This additional fexibility is due to the removal of the binding mounting plate within the ski from midfoot back. The forebody of the ski in AutoDrive has less torsional rigidity which allows the skier to really shape the turn entry any way they want.

I'm not familiar enough with other systems to comment at length on them but I think it is safe to say that some systems do allow more underfoot flexibility but others do not. I also think the underfoot flexibility systems are enabled through the removal of the mounting plate in the ski. When I look at systems by companies like Atomic, Head, Rossi, etc I basically see a plate that is factory mounted and drilled specifically for the company's bindings. Thus, I think it is safe to say that the design change for the ski is very simply that the ski designer knows exactly where the ski will be drilled and the exact flex characteristics of the binding interface.

Anyway, those are my layperson impressions of the existing systems. I'm quite interested in finding out the outcome of your bench tests and other research.

Aar
post #9 of 28
Tom/Pm..guinea pig here..HEHEHA..ok now that you've got me going on this tangent..hey I love doin'this kinda stuff..'SPECIALLY when it pertains to skiing!!
Sheesh..I thunk I've fiddled with these things..skiing../bindings/skiis..for..like EVER..then along comes a NEW question..thanks..

Ok..no.. I didn't break out the mic's..I really think that measurements to within 1/16" are ok..((here))setup plusthe testing method..risk of damaging expensive mics..on risky/not tested measuring set ups involvng the hand compressing of fairly strong springs..

Ok here's how I did it..didn't take long.
I placed the ski tail down on the scale on the stolen sign.I used a 2x4 about 3' long braced across the heelpiece..and with both hands I pressed down..watching the scale.I could nail it down to within a couple of pounds..the beginning of travel..end of travel..within about 7/8 lbs.

You and I were both in luck!..3 of my other ski friends had FOOLISHLY entrusted their skiis to me for service(sure I ski them when they turn their back)..ahh..I know what I'm doing..bit of testing for "research purposes" will never hurt..ceratinlly not as much as when I "borrow" them.And of course I'll tell them..maybe.

4 skiis.

Lowest activation point..15 lbs.
Highest activation point 80 lbs.

Lowest pressure to attain maximum travel..80 lbs.
Highest pressure to attain maximium travel..110 lbs

Minimum travel..3/8 "
Maximum travel..11/16"

Individual tests..:

Ski 1:..20 to 80 lbs..1/2" travel
Ski 2:..15 to 100 lbs 7/16" travel
Ski 3:..80 to 110 lbs 3/8"travel
Ski 4:..40 to 90 lbs 11/16" travel

I'll be swimming in the pond..like a good little fish..waiting for the hook..
post #10 of 28
Quote:
Originally posted by PhysicsMan:

Actually, I was fairly amused that maggots (who are sometimes maligned for their lack of technical expertise) picked right up on my question.
Some maggots actually work in shops and don't mistake self-serving, techno-babbling, one-upsmanship among instructors for technical expertise.

Quote:
Originally posted by Arnold:

Individual tests..:

Ski 1:..20 to 80 lbs..1/2" travel
Ski 2:..15 to 100 lbs 7/16" travel
Ski 3:..80 to 110 lbs 3/8"travel
Ski 4:..40 to 90 lbs 11/16" travel

How's about letting us know what bindings were on skis 1-4?

Forward pressure "phantom" releases can happen when the ski is rapidly deflexed, think springing up from the trough of a mogul, or a pronounced jump turn.

I wonder if it's possible for failure or fatigue in a forward pressure spring to go undetected in a standard release torque test?
post #11 of 28
Thread Starter 
AarHead - I'll reply to your spot-on comments in a new thread about integrated bindings, probably tonight or tmmrw.
-------------

Arnold - Thanks once again!

From your data, I calculated approximate spring rates:

Ski 1:..20 to 80 lbs..1/2" ..travel -> 21000 newtons per meter
Ski 2:..15 to 100 lbs.7/16" .travel -> 34000 newtons per meter
Ski 3:..80 to 110 lbs.3/8" ..travel -> 14000 newtons per meter
Ski 4:..40 to 90 lbs..11/16" travel -> 12750 newtons per meter

The worst case scenario of a binding interfering with the flex of a ski would be the binding with the stiffest forward pressure spring, ie, your ski #2. I need to make up some drawings and get them up on the web before I can post the first set of results/calculations. When I have them done, I'll start a new thread and post a link to it here. Thanks again.
--------------

Ugli Pupferknick:

> ...I wonder if it's possible for failure or fatigue in a forward pressure spring
> to go undetected in a standard release torque test?...

Not only do I think its possible, I think its almost certain to go undetected.
--------------

Tom / PM

[ August 26, 2003, 03:25 AM: Message edited by: PhysicsMan ]
post #12 of 28
EEeek..I somehow just knew that someone would ask this..seeing as how I was fiddling around..I got those skiis done..and back to the owners..I just tested 'em/wrote the info/down.From memory.

Ski 1 I remember had Salomon.997
Ski 2 had older Salomon. ...plastic
Ski 3 had old metal Salomon...OLD..
Ski 4 had metal Tyrolia's..I'm not really a Tyrolia man so I'ld only be guessing at their age.

When I dropped these off I picked up a pair of skiis with Salomon 957 C.These tested the same as the first ski 1..this didn't surprise me.
I also was given a pair of Rossi 9S with Tyrolia 790..these I will just drop off at a charity today..but I did test them too!..40 to 90..7/16" travel.
There was also a pair of later Markers in a box to be mounted..I didn't really look at them.Maybe I'll test them/post when I do them.
And a pair of ANCIENT Salomon 747 metal "E".s..that are gonna go on a mono setup.Ditto.

Phantom releases..
Personally..I think that any binding during testing that exhibits weak forward spring pressure..should be rejected.And I have done it..are they unsafe?Depends..I have told people of this..and they've said they never had problems.Some rental bindings..it simply amazes me how they stay on.
It does affect the release value to a very small extent..not really noticeable.
It can have a noticebale effect on the release value if the heel is adjusted too far forward..and the boot is jammed in.
Bindings with a large screw to control the forward pressure..have been notoriously cranked up with a huge screwdriver..AFTER the boot is in the binding.This can/has led to coil bind..and NO release.

I think phantoms are caused by the heelpiece jamming in it's own track..either caused by ice/snow/road grit..not greased..OFTEN without adequate spring travel to begin with(junk/worn track)Some bindings you simply cannot take the heelpiece of it's track..to clean/lube..Others..slide easy..on/off.OR by the flex of the ski/lifting of the boot heel to one side/torsional twist.This doesn't allow the spring pressure to force the heelpiece forward.
Dampning in this area started..a LONG time ago..some bindings had dual springs here.
I don't think that any use would not allow the spring to maintain heelpiece contact..UNLESS the binding was not jamming in it's own track.
It has been said that at extreme speeds..on a rough course can cause the heel of the boot..to bounce up and down to the point where it is vibrating..the heelpiece moving back and forth rapidly under spring pressure.ADD the flex of the ski to this..maybe some torsional twist of the ski/twisting the binding track,junk in the track..out ya come..
post #13 of 28
Quote:
Originally posted by PhysicsMan:
Ugli Pupferknick:
> ...I wonder if it's possible for failure or fatigue in a forward pressure spring
> to go undetected in a standard release torque test?...

Not only do I think its possible, I think its almost certain to go undetected.
Tom / PM
Why? I would assume (I know, there's the rub) that a forward pressure spring that was applying less forward pressure than the bindings is designed for would allow the boot to "slip" out of the binding at lower torque than one applying designed forward pressure and vice versa. I believe that would be a reason for the binding to fail when adjusted within the "in use" test range on the DIN chart even if the torque adjustment springs are functioning within specification. What am I failing to take into account?

Aar
post #14 of 28
Thread Starter 
> ...What am I failing to take into account?...

If they set the release values by a torque wrench or any other independent measuring device / machine (ie, and not by simply setting the visible on-binding indicators to the presumed correct values), then by definition, the bindings will release at the correct values.

In the other case, if the tech simply uses the on-binding scale and indicator, as you suggested, the binding will likely not release at the expected value, but the size of the error will depend on the detailed design of the binding.

For example, consider a sideways release at the toe. In some bindings, movement of the boot past a certain point on the wing is integral to the release process, whereas in other bindings, the internal mechanism of the binding completely controls when the wing will snap open and release the boot. In the latter case, the wings will snap at the same sideways force whether you are pushing on them with a boot or with your hand (ie, and zero forward pressure). Obviously, most bindings fall between these two extremes.

Tom / PM

[ August 26, 2003, 09:08 PM: Message edited by: PhysicsMan ]
post #15 of 28
Tom:

Thank you.

The shop where I moonlight tests every customer's binding every time we adjust it and tests all the rental bindings once a season at different DINs. Since the other shops I've worked at have the same policies and shop owners I meet complain of the requirement to test whenever the topic comes around I assume all shops test every binding at adjustment time. At least, I assume they adhere to the industry standard of testing customer's skis once per season and once for every 25 days of skiing when they adjust them throughout the season. Thus, I figure most shops could not simply adjust a binding and send it out the door unless they had records of testing it that season.

Aar
post #16 of 28
Boots don't "slip out" of bindings per se..With homogenization(the real inception of din)..in the early 70's..boot/binding interface was pretty muich standardized.ie..toe/heel height,toe/heel configuration.True some adjustments on some bindings remained for toe/heel height..and for toe configuration..wing adjustment.I can't remember when heel height pretty much left..I'm thinking around the mid to late 80's.
When "step in" bindings first came out there was next to no adjustment for forward pressure..BUT there was heel height adjustment.
True..before din homegenization/standardization..there were different boot heel configurations..and different binding heel piece configurations.Some were not compatible.In other cases it was really not possible to even adjust the heel height to work with some bindings properly.
The earlier of the "step in" bindings..heel height/boot heel configuration was critical..you stepped in..the binding heelpiece did not move backwards.The boot was almost jammed in there.There was no forward pressure.True with some boot heel/binding heelpiece configuration it was a pretty good fit.And the binding heelpiece did release properly ina forward fall.In other boot heel and binding configurations the boot did release well..it was binding/jamming on it's attempted release.This ranged from perfect to unsafe.
And chewed up the ski boot toes/heels.
Some old heelpieces used basically the same spring..and allowed for some forward pressure on the rear of the ski boot.The binding did slide somewhat towards the rear on release.These were junk.You ended up having to jam your boot(chewing it up)into these things.These stupid things were HARD to get on.And when in..they releases at WAY to high a level.Backing off the release..meant next to no forward spring pressure on the rear of the boot..and a release way too low.The boots came out of these things easy.
Next came the "latch in" step in bindings.These had to be manually latched in.BUT the advantage here was that the forward pressure could be controlled.True there was none.But at least with the boot now secured with little..or no forward pressure they could work on making the boot heels and binding heelpieces compatible and concentrate on the pure release.These worked ok.There wasn't enough ski flex in those days to alter the overall length of the distance between the toe and heelpieces.And the binding heepiece could not move backwards..therefore no phantom releases.
Latch ins stayed around..din homogenization/standardization came in.The boot heelpieces and the binding heelpieces were standardized.Forward pressure springs..AND adjustments were added to bindings.The true step in bindings..not latch ins..came into their own.Incorporating their own forward pressure springs,adjustments.

Careful observation of step in bindings in action shows the bottom of the boot heel pressing down on the lug of the heelpiece.Further pressing down of the boot heel jams the part of the boot between the sole and the heel and part of the heelpiece.Somein's gotta give.The forward pressure spring now comes into play.The binding heelpiece is now forced backward against spring pressure.Continud observation..and at some point the heelpiece moves forward..(it has to)taking up a position against the heel..if it is adjusted properly..there will be plenty of travel..the binding forward pressure spring will move the heelpiece forward..in event that ski flex changes the distance between the bindings.

If you back off the release on the heelpiece..and test the binding..it will have x.If you have a weak forward pressure spring..the actual release of the binding doesn't really change.If you adjust the binding so that the forward pressure adjustment is almost at the end of it's travel.In effect..to allow the maximum amount of forward travel.This does not really affect the release.The release is pretty much only effected/affected by the upward pressure of the boot heel..where it contacts the bottom of the area on the rear binding heelpiece.

Hope this clears this up..
post #17 of 28
Arnold, etc., I agree that a lack of forward pressure due to a failing forward pressure spring wouldn't affect release at the heel, but wouldn't it prevent proper coupling in the toe cup of the binding and affect release at the toe?
post #18 of 28
Good point!Well sure it would at some point..if the spring was THAT weak..(even 15 lbs of forward pressure..maybe as low as 7 or 8 is plenty..providing the heelpiece can slide easily in it's track)((this allows the forward pressure to not only maintain forward pressure on the heelpiece/heel of the boot..BUT allow the toe of the boot to be continually forced into proper contact with the front,sides(wings) of the toe piece..)) the binding was flopping around/or jamming in it's track/or the housing broken..This wouldn't apply to an older latch in binding..without a spring.
post #19 of 28
Thread Starter 
FWIW, I just started a new thread which contains an analysis of whether a boot in a conventional binding has even a remote possibility of interfering with ski flex. Comments?

Tom / PM

[ August 29, 2003, 10:07 AM: Message edited by: PhysicsMan ]
post #20 of 28
Thread Starter 
Arnold - I just got a chance to look back at this thread. Your earlier post on the evolution of bindings (4 msgs above this one) was GREAT and was pretty much exactly the way I remember things going. Thanks.

Ditto on your response to Ugli's question about if the forward pressure becomes too low.

In the other direction (ie, excessive compression), I would add one more comment. In the experiments I reported in the other thread, putting 150 lbs all on one ski did compress the forward pressure spring to its limit on that ski. I don't know if running into the limit at that low of a loading was an isolated case and simply due to a poor mounting job, or pretty typical of those particular bindings, but I would certainly like to see more forward travel than that.

Tom / PM
post #21 of 28
I think what we really have to look at here is "average Ski".."average skier"..under "average skiing condtions.(or simulated)

We'd have to establish some parameters..a 200 plus lb Olympic skier..putting the boots to a ski from a 70mph plus blast..with enough leg strength to leg press 1200 lbs..

The sheer loadings on this ski from speed/vibration..sheer brute strength..and most doubtedly a ferociously stiff ski..
If someone like this tells me he can flex a ski..into coil bind with conventional non-intergrated bindings he can.

If the ski is a soft ski..and worn out..a strong skier probablly can too.

But for the 99.9% of us mere mortal skiers..I say nope.

I do of course appreciate your test..I too have seen POOR mounts,gummed up,salt corroded tracks..literally the other day a neighbour was throwing out some skiis..hey these might do for some testing..sure..they were soft..and beat..and the heelpiece was so corroded..it could not be adjusted..not only that..the track was corroded to..so that the heelpiece couldn't even move.I left those in the garbage.

There is also the issue of proper toe piece height..there is supposed to be a little clearance.

I gotta go back to the inception of these threads..and agree with you and Aarhead..this adding of plates etc. to the ski..and to the binding mounting..this very seriously confuses/confounds this whole issue..especially what now with the added complexity of availability/and not..of all the various combinations.

Forward testing!
post #22 of 28
Last year I demoed a pair of K2 AK launchers with Salomon
demo binding. I set the toe and heal dins to 7. ( My normal setting) I tested the settings on the snow by twisting
the toe out and leaning forward ( not flexing the ankles )
until release. The rear binding was set so that the heal
of the boot just touched the back of the binding when set
into the binding and pushed the heal back once the boot
was fully into the binding.
The bindings worked find and I felt were set properly.
On my first demo run with the skis a person stopped in the
middle of the slope 100 ft in front of me. The snow was hard.
I did a hockey style stop to the right with the skis chattering
excessively so I lifted the skis to perform a hockey style stop
to the left. About half way thru the stop both skis came off my feet and I proceded to go flying down the hill face first.
Not much fun. Considering the following comment by Arnold:

It has been said that at extreme speeds..on a rough course can cause the heel of the boot..to bounce up and down to the point where it is vibrating..the heelpiece moving back and forth rapidly under spring pressure.ADD the flex of the ski to this..maybe some torsional twist of the ski/twisting the binding track,junk in the track..out ya come..

Questions:

1. Is this a known problem with some binding manufactures?

2. Is there a way to ensure adequate forward heel pressure
to prevent the binding from pre-releasing in a high vibration
situation?

3. I've skiied the Look Nevada bindings for years and never had
this problem with the turntable heal. Is this a problem with
the newer stepins?

Thanks,
post #23 of 28
Thread Starter 
> ...K2 AK launchers with Salomon demo bindings...
> 1. Is this a known problem with some binding manufactures?

Comparing different bindings and binding mfgrs, there are definitely varying ammts of vertical elasticity (at the heel), twist-out elasticity (at the toe) and forward pressure elasticity (ie, travel), and it sounds like you might have been testing these limits. However, even with a quite a bit of chattering in a hockey stop, skis will rarely go much past flat camber during it since there is always considerable friction from the snow on them even during the "release" phase of the "grab-and-release" cycles that constitute chattering. One usually only worries about vert and forward binding elasticity with respect to very agressive skiing in bumps when the binding opens up when the skier pops off a bump (ie, pretty much the opposite situation to a hockey stop).

Is there any chance some other problem (that you are not condsidering) could have been the cause of this particular ejection, for example, worn boots, bad height adjustment (if the binding has such an adjustment), snow under the boot, etc. Anything worn or corroded on the demo bindings this happened on?
---------

> 2. Is there a way to ensure adequate forward heel pressure
to prevent the binding from pre-releasing in a high vibration
situation?

While the set-up procedure you used for forward pressure sounds reasonable, did you also check that the little forward pressure mark/indicator was showing the correct pressure (if there is one on your bindings)?

One off the wall comment: Bindings that are attached to solid plates instead of directly to the ski don't have to deal with forward pressure variations as the ski flexes, and are (in some cases) even somewhat insulated from high frequency vert motion of the underfoot area of the ski.
---------

> 3. I've skiied the Look Nevada bindings for years and never had
this problem with the turntable heal. Is this a problem with
the newer stepins?

Looks still have among the highest elasticity and are excellent performers in situations where the skis are getting buffetted around. With respect to other mfgrs, other than the usual "Markers suck - low elasticity" comments that one always hears, most modern bindings seem to work pretty well. I personally never had a problem like you described, but most of my current binders are Tyrolias FF's (lots of forward pressure elasticity/travel) and Looks.

Sorry I couldn't be more specific.

Tom / PM

PS - Edited for spelling and sentence structure.

[ September 03, 2003, 07:49 AM: Message edited by: PhysicsMan ]
post #24 of 28
blstocker,
Along the lines of PM's questions...
Who set up the bindings for you?
Were they familiar with Salomon demo bindings?

It's possible to be presented with new bindings that the shop hasn't seen before, and just setting the releases to a value, but not checking things like toe height, wings, release plates, etc.
This rarely happens, shops normally advise you that it's not a binding they deal with, but you'll find someone who'll "take a go at it", provided you are prepared to accept responsibility!

Then again, it may have been had a faulty binding.

[ September 03, 2003, 04:12 AM: Message edited by: Wear the fox hat ]
post #25 of 28
Team,

Thanks for the input.

I rented the AK's from a reputable shop at lake tahoe.
They where Salomon reps. and set up the bindings on a
bench at their shop. They also "lever" tested the bindings
to ensure proper release.

I did my own tests once I was on the snow. I was able to
test side release of the toe and forward release of the
heal. I was NOT able to test if the heal had enough forward
pressure on the toe. I checked the binding and unfortunately
there are not WHITE MARKS on this model.

I'll going to check out the Tyrolia FF's as recommended.

Thanks,

Barry

Quote:
Originally posted by Wear the fox hat:
blstocker,
Along the lines of PM's questions...
Who set up the bindings for you?
Were they familiar with Salomon demo bindings?

It's possible to be presented with new bindings that the shop hasn't seen before, and just setting the releases to a value, but not checking things like toe height, wings, release plates, etc.
This rarely happens, shops normally advise you that it's not a binding they deal with, but you'll find someone who'll "take a go at it", provided you are prepared to accept responsibility!

Then again, it may have been had a faulty binding.
post #26 of 28
Quote:
Originally posted by PhysicsMan:
Does anyone know the approximate amount of forward pressure used in bindings (ie, in pounds or newtons) or the spring rate (ie, pounds force per inch of travel or equivalent).

I did a search and found plenty of references to setting the forward pressure, but these were always based on looking at the indicator mark, not an actual value.

TIA,

Tom / PM
The acual forward pressure value in todays bindings is in the range of about 27-28 newton meters.

Coup
post #27 of 28
Thread Starter 
Quote:
Originally posted by coupdevill:
The acual forward pressure value in todays bindings is in the range of about 27-28 newton meters. ...Coup
Coup - Thank you very much for your input. However, I am concerned about your result.

First, "newton-meters" is a unit of torque, not of force. By some chance are you looking at some torque parameter associated with the forward pressure in bindings such as (a) the torque needed to tighten the forward pressure adjusting screw, or (b) the upward torque applied by the leg in order to force a release at the heel?

Second, assuming you meant the unit to be just "newtons", 1 Newton = 0.224808943 pounds force (*), so 27 newtons turns out to be only 6.1 lbs (force), which is obviously way too low.

Where did you get this number (and its units)?

Thanks,

Tom / PM

Note:

* - Google now has a built in calculator and unit converter. This conversion came from:

http://www.google.com/search?hl=en&i...wton+in+pounds

[ September 09, 2003, 08:28 AM: Message edited by: PhysicsMan ]
post #28 of 28
Quote:
Originally posted by PhysicsMan:
</font><blockquote>quote:</font><hr />Originally posted by coupdevill:
The acual forward pressure value in todays bindings is in the range of about 27-28 newton meters. ...Coup
Coup - Thank you very much for your input. However, I am concerned about your result.

First, "newton-meters" is a unit of torque, not of force. By some chance are you looking at some torque parameter associated with the forward pressure in bindings such as (a) the torque needed to tighten the forward pressure adjusting screw, or (b) the upward torque applied by the leg in order to force a release at the heel?

Second, assuming you meant the unit to be just "newtons", 1 Newton = 0.224808943 pounds force (*), so 27 newtons turns out to be only 6.1 lbs (force), which is obviously way too low.

Where did you get this number (and its units)?

Thanks,

Tom / PM

Note:

* - Google now has a built in calculator and unit converter. This conversion came from:

http://www.google.com/search?hl=en&i...wton+in+pounds
</font>[/quote]Sorry! My memory bank was not running at full tilt! It has been sometime since I really spent a lot of time, on this sort of thing, never felt it was of much value other that debateing binding desgin theory. Let my second guess be about 27-28 kilos of force or there abouts, actually pretty std. among binding copanys.
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