Binding Ramp Angle Measurement Thread

[Spats]

How To Measure Binding Delta and Stack Height!

Use digital calipers. Make sure the jaws of the calipers are flat to the base of the ski.

1) Put a boot in the binding and see where the flat part of the boot heel begins. (Heels and toes are beveled.) Remove the boot, and measure from there to the bottom of the ski. (Some binding heelpieces have a lot of forward ramp (i.e. old Look turntables) and the rear of the heel is much higher than the front.)
2) Measure from the top to the bottom of the ski at that point. Subtract 2) from 1) and you have your rear stack height.
3) Measure from the top of the toepiece AFD to the bottom of the ski.
4) Measure from the top to the bottom of the ski at that point. Subtract 4) from 3) and you have your front stack height.

If you have skinny skis you may be able to put the boot in the binding and measure directly from the ski topsheet to the boot. Please note the method you used!

Here's what I've got so far. Please post yours!

9.5mm: Rossignol Scratch (= Look P10/P12/P14 w/no risers)
9mm: Rossignol FKS
7mm: Look PX12 Lifter (corrected)
4.7mm: Salomon S900 w/Fischer RC4 Race boots
4mm: Marker Dukes, with Daleboots (this will depend on your boot toe)
3mm: Fischer FX10 (= Tyrolia Railflex 10)
3mm: Tyrolia SP100 Demo
2.1mm: Marker Dukes, with Fischer RC4 Race boots

Note! 5.5mm of height = 1 degree of ramp angle for a 315 BSL.
Also, 1 degree of ramp angle = your knee moves 9.4mm forward for a 55cm distance from knee to bottom of boot heel.

[Big Steve]

Shouldn't that measurement be called "delta" rather than "angle?"

[Spats]

Good point -- but you can't edit titles. Maybe The Suit or someone will come in and do it.

Anyway, I added the tidbit that 5.5mm of delta = 1 degree of ramp for a 315mm BSL.

[Jonathan S.]

I think the heel piece measurement should be with the boot in the binding -- otherwise, can be hard to measure exactly where the boot heel is going to rest.
Also, maybe this is what you meant in your description, but measurement should be to the ski topskin (since otherwise the varying ski thickness is going to be a factor).

[Mustonen]

Also, maybe this is what you meant in your description, but measurement should be to the ski topskin (since otherwise the varying ski thickness is going to be a factor).

2nded, on both counts, really. Bottom of boot heel to ski topsheet would make sense, no? Maybe while pushing down on the boot.... Also, how about just heel and toe stack height, let john q. reader do the math. Then this thread becomes doubly useful (stack height and delta).

[Spats]

Also, maybe this is what you meant in your description, but measurement should be to the ski topskin (since otherwise the varying ski thickness is going to be a factor).

This only works if you have skinny skis...otherwise the caliper jaws don't reach to the boot sole and the measurement isn't very good. Maybe I have small calipers, or too many fat skis :D

Also, ski thickness doesn't change much between AFD and heel: mine vary by a maximum of 0.8mm, typically <0.5mm. But I'll remeasure and take that into account.


Also, how about just heel and toe stack height, let john q. reader do the math. Then this thread becomes doubly useful (stack height and delta).

That's a good idea. I'll go back and redo those measurements. Updates soon.

[Core Shot]

I would love to see more data.

Seems some of the burlier bindings these days are made with small or no ramp angle since that is better for switch skiing.

Is high ramp angle a dinosaur?

I saw one website (tyrolia I think) that said they lowered their heels since FIS changes allow it (implying that less ramp is better?)

I am so confused

[Jonathan S.]

I saw one website (tyrolia I think) that said they lowered their heels since FIS changes allow it (implying that less ramp is better?)
FIS max stack height for ski + binding (including any plates/lifters in between) = 50mm. (Another max is 43mm for bottom of ski boot sole to top of any interior footbed.)
Any modifications to comply with that reg would affect delta only if toe unit stack heights were not changed in a corresponding manner (which could very well be the case).

[splat]

Can I throw a unicorn in the mix, spats? Won't the angle can be affected by the curvature of the core in the ski and mounting positions, i.e., if you go back -2, the taper of the core thinning to the tail can reduce the effective angle (higher heel), if that is the delta you're measuring?

[stuckathuntermtn]

This is the most ridiculously anal thread I have ever seen.

Also, the ramp angle on bindings with separate heel and toe changes depending on your boot sole length. So pretty much only a few systems, and of course AT bindings other than dynafits are the only bindings with a steady ramp angle.

[Spats]

Can I throw a unicorn in the mix, spats? Won't the angle can be affected by the curvature of the core in the ski and mounting positions, i.e., if you go back -2, the taper of the core thinning to the tail can reduce the effective angle (higher heel), if that is the delta you're measuring?

Yes, it can. This is why the revised technique in the first post measures and subtracts the thickness of the ski, which should take into account any variations due to core profiling, mounting position, etc.

Thanks to Jonathan S., Mustonen, and Big Steve for helping debug my original post. Unfortunately I haven't added any new bindings to my gear closet yet...perhaps others can add their own?

Re-measurements of bindings on the list are also encouraged, to see whether the results are consistent.

[Gripen]

This is the most ridiculously anal thread I have ever seen.

Also, the ramp angle on bindings with separate heel and toe changes depending on your boot sole length. So pretty much only a few systems, and of course AT bindings other than dynafits are the only bindings with a steady ramp angle.

That's why the OP stated BSL and why it is called delta, not angle.

[splat]

Yes, it can. This is why the revised technique in the first post measures and subtracts the thickness of the ski, which should take into account any variations due to core profiling, mounting position, etc.

Thanks to Jonathan S., Mustonen, and Big Steve for helping debug my original post. Unfortunately I haven't added any new bindings to my gear closet yet...perhaps others can add their own?

Re-measurements of bindings on the list are also encouraged, to see whether the results are consistent.

Yeah, that's right....now that I read it again I see you have taken that into account. well done!

[The Duke of Hurl]

Maybe I have small calipers...

No need to confess your shortcomings here...;)

[stuckathuntermtn]

I can't wait for the discussion on how +/- 1mm totally changed the ski for someone.

Fuckers.

[single]

I can't wait for the discussion on how +/- 1mm totally changed the ski for someone.

Fuckers.

dude. you suck.

[Spats]

Another tidbit: assuming 55cm from knee to bottom of boot, this means your knee will move approximately 9.4mm forward for every degree of ramp angle in the binding.

If you can tell a 1cm difference in mounting point, you can probably tell a 1 degree difference in ramp angle.

[stuckathuntermtn]

dude. you suck.

Go shine Merkel's shoes.

[Core Shot]

click on the link for a more readable version.
Its interesting how the racing geeks really value this info.
There also seems to be some ramp angle in the boots
Why does the R2006 have so much less ramp than a RS130 ?

http://racingusa.dynastar.com/doc/Binding%20ramp%20formulas%2010-11%20dyna.pdf


Calculation:
Equation:
arctangent Opposite = Difference between Binding heel height and toe height in mm Adjacent = Athlete's bootsole length in mm
hypotenuse
Degree (q) or Ramp angle adjacent
[(arctan(q)=opposite/adjacent)*(180/3.14159)]
BINDING & BOOT RAMP ANGLES
degrees, depending on size degrees, depending on size degrees, depending on size degrees, depending on size degrees, depending on size
Small size boots more ramp Large size boots less ramp
(q)=opposite/adjacent *
*the result of the above calculation is in radians and needs to be converted to degrees by multiplying by (180/Pi) Pi= 3.14159
opposite

[cyclerower]

is there a reason the low-end bindings have so much more ramp angle than the high-end ones?

[splat]

If you can tell a 1cm difference in mounting point, you can probably tell a 1 degree difference in ramp angle.

Skiing in demos to find optimal bcl's a bit, I find the dif in 3mm all the time, since that's one click on demo bindings. Ramp angle adjustments should be no different for anyone who takes the time to experience the change in various heel heights.

[Shorty_J]

Splat: which demo bindings are you using to allow 3mm changes in location?

I just installed Railflex II's on some planks, which have three locations (-1.5cm, 0, +1.5cm), but maybe I could "fake" a smaller increment by moving the toe peice to a larger BSL and the heel piece to a smaller bsl. I think this would allow a 5mm difference though.

[splat]

Tyrolia SP130s.

[Tuckerman]

This is what I picture Epic Ski threads are like only all summer long.


Its not your equipment.

[61N149W]

I am in the process of mounting Rossignol FKS 180 XXL bindings on Rossignol S7 skis. I am very aggressive, but I do not ski switch. Is there any reason for me to install the "kit lifter"? I honestly did not know there was such a thing. The kit lifts the toe piece 5mm. If I understand this correctly, this effectively takes away the ramp if installed. Do I need it? What's it for?

Thanx

[Shorty_J]

I just checked a couple of my pairs of binders and came up with the same delta for Tyrolia RF14's (3mm), but got a different value for Loox PX12Ti lifters (6.5-7mm).

I used calipers to measure but it was on fatter skis so I had to eyeball the under side of my boots to get the measurements. And I didn't measure from the very front or very back of my boots because they have a small upward bevel built in to the sole. Instead, I measured from the front-most flat section of boot to the rear-most flat section of boot.

Side question: does anyone think that different binding deltas are more suited to different mount locations? I.e. is a flatter/lower delta better with a more centre mount, and a steeper/higher delta better for a more rearward mount?

[Spats]

I just checked a couple of my pairs of binders and came up with the same delta for Tyrolia RF14's (3mm), but got a different value for Loox PX12Ti lifters (6.5-7mm).

Good call. I remeasured mine and I'm getting more like 7mm. I'll update.

Yes, you definitely have to measure from the flat part of the boot. I measure the toe at the AFD, and the heel at wherever the bevel stops.

Keep in mind that toe thickness is not constant, so different boots will have more or less space under the toe on non-adjustable bindings (e.g. everyone but Salomons and Dukes).

[gunniride]

I would be very interested to learn the delta of salomons, dynafits, and fritschis. I have tweaked the angles of my bindings other than the dynafits so my measurements wouldn't be worth anything (and I don't have calipers).

Considering adding the 4-5mm shim under my wife's Fritschis for the same reason I've done it on mine, but so far I have resisted.

Anyone else ever shim one side of their bindings to make the ski perfectly flat under foot and not rocked to one side or the other?

[Shorty_J]

I removed the plastic spacer on the toe piece when I had Fritschi's. Added a few mm of forward delta. I had to shorted the screws with a dremell before re-installation.

[Spats]

Anyone else ever shim one side of their bindings to make the ski perfectly flat under foot and not rocked to one side or the other?

They used to make those as a predrilled plastic part for popular bindings in the 1980s...they were called "cant plates". I have a pair with Salomon hole pattern sitting in the closet (they're much too extreme for me).

These days people generally try to plane boot soles instead, because it works with all your skis and you don't end up with a left and right ski...and you can fake it a little bit with boot cuff tilt adjustments at the ankle (often incorrectly called "canting"), which didn't exist back then.

[Spats]

Added measurements for Salomon S900, and another for Marker Duke with a newer boot.

[Crampedon]

Another tidbit: assuming 55cm from knee to bottom of boot, this means your knee will move approximately 9.4mm forward for every degree of ramp angle in the binding.

If you can tell a 1cm difference in mounting point, you can probably tell a 1 degree difference in ramp angle.

Now we're talking. If I want my knee more forward over my toe, (stiff ankles!) increasing ramp angle help driving the knee forward and down?

[Spats]

Now we're talking. If I want my knee more forward over my toe, (stiff ankles!) increasing ramp angle help driving the knee forward and down?

Yes. Increasing the forward lean on your boot (if it has an adjuster) can also do this -- but unless you also increase the ramp angle *inside* the boot (with heel lifts), your stiff ankles may not like the result.