or Connect
EpicSki › The Barking Bear Forums › On the Snow (Skiing Forums) › Ski Gear Discussion › stand height & delta angle illustrated
New Posts  All Forums:Forum Nav:

stand height & delta angle illustrated - Page 2

Quote:
 Originally Posted by bud heishman I am no geometry whiz but do know that as lou states, angles can not be communicated in millimeters. and silly me, but when I hear "ramp" I think of angles not specific heights in mm's. This is in part why I tryed to do the graphic above to demonstrate how different binding heights between toes and heels create different angles that again will change with boot sole length mounted in the system. I am now confused too and will heretofore try to describe my intent rather than using a term that may be misinterpreted or misused on my part.
Bud, i was very interested in the thread you started from the moment i saw its title. I think that you should continue. IMO the problem was that you and Beta used different words to explain the same things. That was what confused people (and i was also a little bit confused too). So don't give up!

The only downside is that at the moment i am writing these things, less than 500 people decided to take a look at this thread. This shows one thing: the majority of skiers do not care about these things. Too bad b/c they are extremely important IMO.

Jamie
[quote=bud heishman]

This is in part why I tryed to do the graphic above to demonstrate how different binding heights between toes and heels create different angles that again will change with boot sole length mounted in the system.

QUOTE]

Yes but let's not forget that some plates can influence that. I have the Marker WC Piston Control plate and the toe is 2mm higher than the heel. This influences the binding ramp b/c i have 3mm of ramp instead of 5mm. this is important b/c i have less delta angle in degrees created. But this probably goes for a few bindings so only a few people benefit from this but it is good to know. If i had 5mm of binding ramp, i would have aprox. 1 degree of delta in the same size.
Quote:
 Originally Posted by sywsyw Bud, i was very interested in the thread you started from the moment i saw its title. I ...The only downside is that at the moment i am writing these things, less than 500 people decided to take a look at this thread. This shows one thing: the majority of skiers do not care about these things. Too bad b/c they are extremely important IMO. Jamie
Take heart and remember that,
"From a tiny acorn the mighty oak tree grows",or
"From a tiny acorn a mighty oak tree grows", or
"The mighty oak tree grows from a tiny acorn"
or something like that...

Angle calculations

Quote:
 Originally Posted by sywsyw Louis and Bud, thank you for your replies. Ramp angle is typically referred to in mm's. The angle increases in shorter boots and decreases in longer boots. Delta angle that is external influences (binding ramp) increases on shorter boots and decreases on longer boot soles. I measured the binding ramp which is 3mm. I measured the ramp angle which is 10mm (toe=10mm heel=20mm) and i also looked at the graphic and for my size (25.5 MP 294mm) i have just a little more than .5 degrees of delta.
SYWSYW:
I beg to differ and wish I could offer an explanation as to why your answer is incorrect but a 10mm change in height over 294mm length is 1.95 degrees., 3mm change over 294 is .6 degress. So at the very least you have 2.55 degress ramp. In actuality the ramp isn't measured over the length of the boot but over the length between the two points on which the boot or foot is suspended.

So in the case of binding ramp it is measured between the AFD and the heel pad. In the case of boot ramp you must remove the zeppa and measure its length. And if the zeppa has toe spring (not completely flat zeppa, but zeppa with reduction of overall angle, usually changing at the ball-of-the-foot you must measure between rearmost portion of zeppa and ball-of-foot.

I realize this seems like nitpicking but changes of only a few mm can make substantial changes in angle over the short distances we are using.

The overall angle you have quoted is the lowest by more than half than I have ever seen as angles of 5 degress and more are typical. See my article in this season's first issue of ski racing.

Lou
Interesting..., but : ;

What are the benefits of a reduced differential (low delta angle) and what advantages are there to a high differential (high delta angle)?

I have a moderately high delta on my Fischer WC RC with a Rossignol 140 T-plate binding. This is going to be used for high speed, hard snow cruising and masters racing.

I have a moderately low delta on my Intuitive 74 with Look P8 with the Maxplate under the toe and the Dynastar Wine-bottle plate (without the Look plate at the heel). This is my western conditions all-mountain ski.

What happens to my skiing if I change the delta angle on the skis?

Cheers,

Barrettscv
Quote:
 Originally Posted by barrettscv Interesting..., but : ; What are the benefits of a reduced differential (low delta angle) and what advantages are there to a high differential (high delta angle)? I have a moderately high delta on my Fischer WC RC with a Rossignol 140 T-plate binding. This is going to be used for high speed, hard snow cruising and masters racing. I have a moderately low delta on my Intuitive 74 with Look P8 with the Maxplate under the toe and the Dynastar Wine-bottle plate (without the Look plate at the heel). This is my western conditions all-mountain ski. What happens to my skiing if I change the delta angle on the skis? Cheers, Barrettscv
One setup is going to be closer to correct for you than the other. I don't believe in changing your delta based on skiing conditions/terrain. Being in balance is being in balance no matter what you're doing. I think you're in Chicago so you may have a tough time finding someone there who can help you, but if/when you get out West it may benefit you to search out someone (like Bud) who specializes in this area and can analyze all of the variables in the complete system (your body, boots, bindings, and skis) to determine what should work best for you.

That being said, the trend has been toward lower deltas and a more upright stance on modern shaped skis. We just don't need to pressure the shovels like in the old days so a more centered stance works best. Many times too much forward lean / ramp angle / delta (any combination) contribute to actually forcing a skier into the backseat to maintain balance.
Quote:
 Originally Posted by louis rosenfeld SYWSYW: I beg to differ and wish I could offer an explanation as to why your answer is incorrect but a 10mm change in height over 294mm length is 1.95 degrees., 3mm change over 294 is .6 degress. So at the very least you have 2.55 degress ramp. In actuality the ramp isn't measured over the length of the boot but over the length between the two points on which the boot or foot is suspended. So in the case of binding ramp it is measured between the AFD and the heel pad. In the case of boot ramp you must remove the zeppa and measure its length. And if the zeppa has toe spring (not completely flat zeppa, but zeppa with reduction of overall angle, usually changing at the ball-of-the-foot you must measure between rearmost portion of zeppa and ball-of-foot. I realize this seems like nitpicking but changes of only a few mm can make substantial changes in angle over the short distances we are using. The overall angle you have quoted is the lowest by more than half than I have ever seen as angles of 5 degress and more are typical. See my article in this season's first issue of ski racing. Lou

Yes you are correct and the overall angle is incorrect.

Boot ramp: i have to measure the height of the toe of the bootboard, the height of the heel and its length. I measured it and this is what i found: toe=9.5mm heel=19.5mm but i can't measure the length b/c i can't take it out anymore (it's a long story). So i can't measure it. Is this how the boot ramp should be measured? I think it is. And reading some posts again, this angle is in fact the delta angle you have been referring to, right? This is what actually confused me (i think). Reading Beta's posts the delta angle is in fact the boot ramp angle. And yes, in a 25.5 the ramp angle/delta increases compared to the same toe and heel height of the bootboard in a 28.

binding ramp: how do you measure it? The standheight of my Marker Comp 14.0 EPS is 19mm (w/o ski). This number is taken from a Marker website. from what i know, the difference in height between the heelpiece and the toepiece is 5mm.

So the delta angle/ramp angle is different from the binding ramp and from the stand height (with or without the ski ). So they are three different things!
Thanks again! I am trying to better understand these things so that i can use them later.

Jamie

Formula to determine Ramp Angle of Boot?

To find degree(s) of Ramp Angle, Is it not height divided by length X 57.3 (57.3 being used anytime the height is less than 50% of the length)?

Math brains where are you?

coup

Quote:
 Originally Posted by sywsyw Thank you for your answer. Yes you are correct and the overall angle is incorrect. Boot ramp: i have to measure the height of the toe of the bootboard, the height of the heel and its length. I measured it and this is what i found: toe=9.5mm heel=19.5mm but i can't measure the length b/c i can't take it out anymore (it's a long story). So i can't measure it. Is this how the boot ramp should be measured? I think it is. And reading some posts again, this angle is in fact the delta angle you have been referring to, right? This is what actually confused me (i think). Reading Beta's posts the delta angle is in fact the boot ramp angle. And yes, in a 25.5 the ramp angle/delta increases compared to the same toe and heel height of the bootboard in a 28. binding ramp: how do you measure it? The standheight of my Marker Comp 14.0 EPS is 19mm (w/o ski). This number is taken from a Marker website. from what i know, the difference in height between the heelpiece and the toepiece is 5mm. So the delta angle/ramp angle is different from the binding ramp and from the stand height (with or without the ski ). So they are three different things! Thanks again! I am trying to better understand these things so that i can use them later. Jamie

formula

Coup:
Trying to be subtle here but, what the _____ is that formula? I can't recall seeing anything like it. I'm not a math head per se, but as an engineer I was at least schooled in trigonometry. And the formula necessary to determine angle is straight from trig.

But for those out there without the benefits of a table or training to use them I suggest another way. And it is the one I use in my shop. Admittedly it is more expensive, but as many on this thread are very involved with their skiing perhaps the expense is worthwhile.

There are digital levels available that read in degrees. I use one with a very simple jig that allows me to measure boot ramp, binding ramp and their combined ramp.

Lou
Quote:
 Originally Posted by louis rosenfeld Coup: Trying to be subtle here but, what the _____ is that formula? I can't recall seeing anything like it. I'm not a math head per se, but as an engineer I was at least schooled in trigonometry. And the formula necessary to determine angle is straight from trig. But for those out there without the benefits of a table or training to use them I suggest another way. And it is the one I use in my shop. Admittedly it is more expensive, but as many on this thread are very involved with their skiing perhaps the expense is worthwhile. There are digital levels available that read in degrees. I use one with a very simple jig that allows me to measure boot ramp, binding ramp and their combined ramp. Lou
Lou,