Technical effects of binding placement fore and aft

Do you already know the answer? Hopefully it isnt a test; I don't want to risk failing.

I would like to describe this in terms of where your CM is in relation to the sweet spot of the ski, when you are in a normal neutral stance (not forward or back).

Normal Mount: In the above position your CM is at the sweet spot.

Forward Mount: Your CM is ahead of or toward the front of the skis sweet spot.

Rearward Mount: Your Cm, in a natural position is toward the back of, or behind the skis sweet spot.

Most of you probably already knew that. now the question is: How do you ski each of these setups, and what might they be good for?

The normal mount is of course the recommended position on all skis. This is typically the best position for a variety of conditions (powder, park, groomers, edge to egde quickness, etc). I find this to offer the most versatility on a ski. Msot expert skiers know how to move their body position so taht their CM hits different parts of the sweet spot of the ski. The skier will do this based on terrain they are skiing, and point they are in a turn. If you ski one terrain or do one type of skiing exclusively, you may want to specialize your skis to one of the other options. Being a racer, on all skis, regardless of type, I feel more comfortable on groomers when I am mounted in the proper position. I'll get to why in just a few lines.

A forward mount obviously decreases the amount of tip in front of you. Naturally this is great for creating equal swing weight for your skis, and makes it easy to land large drops/jumps and not end up on your back side. In tight places the skis will tend to hang the tails up on terrain features. Also, if you ski these skis too far froward, you will end up lifting the tail off the snow, so you rarely will see a rider skiing far forward on this type of mount. This is why I don't usually enjoy this mount on groomers. If a backseat driver were to get on the skis they would love them, not because they would fix how they skied, but the rider would now be over the sweetspot, even if they were still skiing in the back seat.

A rearmoutning position is something that I have only heard of in recent years. I have heard of it on powder skis most recently. This mounting position is great if you have NO problems moving forward over your tips. To get yourself over the sweet spot on the ski you have to always be up over your tips, or if you are working the ski in a freeride type situation, you have to be able to move back and forth over the ski, but if you get in the back seat... you better be able to get over the tip. This would be fun in powder - if you werent catching air. If you start dropping cliffs, you may want to get more tail behind you so you arent burying yourself or slapping the snow on every drop. With a short tail in powder you can easily sink the tail and use slight rotary to "break" and slow yourself down, but again you will have to move yourself forward again or you will constantly be fighting staying up near the sweet spot. I have also heard of similar mounts to this used in SL racing, but that is slightly off topic.

I hope that helps a little bit.

Later

GREG

MoJo binding placement results

On my Head Mad-Trix MoJo's, (124/89/117) the default binding position resulted in very quick turns, especially in bumps, where the ski would pivot quickly and easily. Carved well, deep snow O.K., but ski felt "short" for its length. (176)

Head says the boot center mark on this ski is a compromise position between park and pipe performance, skiing backwards, and powder.

After playing with a pair of MoJo's mounted with demo bindings that allowed me to play with fore/aft position, I remounted my bindings 1 1/8" to the rear of the boot mark. This significantly improved deep snow performance, (ski felt 10cm longer than before, much better float) and did not noticeably affect carving on groomed. The ability to quickly pivot was greatly reduced. Stability in chop at speed was improved. The rearward mounting also was consistent with the mounting position (relative to ski length) of my other gear.

After remounting, I was much more willing to let the skis run in deep snow, where before, at the manufacturer's default position, I had to be concerned with keeping the tips from diving, especially in west coast "powder".

Also, ditto the above post in regards to the tails hanging up on terrain features when mounted in the "forward" position.

one major thing to consider that most peoplenever think about is where is the center of the sidecut. Often times the center of sidecut (narrowest point) is a little in front of the recomended mount postion. From my experiences, I prefer a slightly forward mount, 1-3 cm in front of the recomended mount point (on my K2's) and while there has been occasionally (VERY rare) a tail grab, its has been so rare that it wasn't enough to discourage me from mounting there and I found the ski much quicker turn to turn. However, on skis where the mount was more forward (around +5cm), 4FRNT and Pistol, I noticed what I described as to much tail, the skis didn't feel like they wanted to turn properly and felt like they wanted to bury the tips (even in around a 180 length).

Now, on my Fischers, I can move the binding about +/- 1.5 cm from neutral, and on those, the forward position felt foreign, I could feel the shovel, but it just didn't feel like it wanted to engage. However, on the neutral point, it felt very under foot, and not very forgiving to fore/aft adjustments, however in the aft mount position, the ski felt much more forgiving and just as capable. Comparing the Fischers (Rx8Fti railflex) to the K2's (PE's), I think the biggest difference is where the sidecut is located, sidecut center felt underfoot on the Fischers and Forward on the K2's. Personally I think its more important to match up the sidecut center and mount point (to your preference of CM location - I like the sidecut center under/near the ball of my foot).

Now in terms of how they ski, with a forward mount, you have less leverage to engage the shovel, thus you need to actually be more forward to engage the ski properly (this seems to disagree with previous comments). With that said, if this is a powder oriented ski, this need to be more forward also then means the ski should be longer (to prevent the feeling of tip diving) to allow the tip to float. On some skis, you may be more prone to "feel" the tail during turns (it may feel stiffer because of the slightly longer effective edge behind the heel), and if that is the case, often times, people will lean back relying on the tail to ski (which is innefficient, although does work).

Now, these examples are somewhat different from racing applications. If you are racer and attack gates (more forward skiing) a forward mount can be beneficial, somewhat seemingly shortening the ski, allowing quicker turns. Conversly, if you are a power racer (really driving by the tails and using strenth and the strength of the ski to propell forward into the new turn), a slightly aft mount can help by providing more length in front of the toe, potentially engaging the shovel better into the new turn (with the aft->fore explosion between turns).

Now, park specific mount point adjustments are a different scenario again. Moving forward helps to center the swing weight for spins, and helps to "center" balance on rails/boxes. Also, a forward mount adds tail length (obviously) which can help when landing slightly aft, skiing out from a jump, instead of bailing. Also, the forward mount (often as far as true center - typically about +7.5 cm) aides switch skiing, making the regular and switch turns more equal.

Just my $.02

Great posts so far. This is really a huge issue and there's a ton of good info on this (especially at Keelty's site realskiers.com). The most important fact to come away with is that the mounting point (midsole mark) may or may not be the best place for you depending on the ski manufacturer and your body stature. I've found that for me I'm much better off using the BoF (Ball of Foot) method for determining a better mounting point (at least as a starting point). All of the already mentioned issues regarding sidecut, waist width, and ski flex will also have an effect.

I still hold a major belief that one of the reasons you sometimes see wildly varying opinions on skis is completely due to the mounting position and the body types of the reviewers. I wish every binding made it easy to adjust the fore/aft position, not only to adjust for body stature, but also to adjust for snow conditions. I'd like to see these adjustments go beyond what we have available today with only a few "static" positions available (Atomic, Tyrolia). I'd like to have much more granular adjustments available.

I agree Noodler, it really depends on how you are built, where you ski, and how you ski that terrain. No two skiers are going to be built alike or ski alike (hence why I used a neutral stance to base my observations from - to give some sense of a constant). The unfortuante reality is that nothing is really constant in this situation, so it really should come down to personal preference, terrain, body build, and technique/skill.
Later
GREG

This answer my question from a few months back on my 1080s and the tails banging into each other and feeling all over the place.

My 1080s are mounted at the recommened spot but I always feel like there is too much tail especially in cutup.

Since I don't ski in the park that often and only ski switch while messing around I wa thinking of mounting them slightly back.

Determining BoF mounting position

Scalce - I'd be interested in how your current mounting position compares to the BoF method of determining the mounting position.

Tools needed: Tape measure (I have a metric one), two 6"+ straight edge rulers, pencil, screwdriver, pen, marker

Here is the method I use:
1. Determine the running length (contact length) - put the ski flat on a fairly level floor. Slide a "straight edge" between the bottom surface of the ski and the floor at the tip of the ski. Slide it in until it is stopped by the contact between the ski and the floor. Repeat for the tail with the second straight edge. If the ski has a ton of camber you may need to press it flat against the floor before doing this to ensure you are getting a true contact length measurement. I like to use long straight edges for this so that I can take the contact length measurement on both sides of the ski to double check that I have positioned the straight edges properly. That's why I prefer to use longer ones that stick out on both sides of the ski. Some people use business cards (or credit cards), but I find that my small steel rulers give me better results. Measure the distance between the "contact" points to determine the true running length and mark the contact points on the ski with a pencil (both sides!).

2. Determine the BoF position - Divide the running length measurement in half and mark this position on both sides of the ski with a pencil. This position is where you want the ball of your foot to be placed.

3. Find the midsole mark on your foot - I use a slightly different method for this than you'll find in other places. I've found that the arch of my foot is much more sensitive than the ball of my foot. I place my bare foot in the shell with my footbed (the footbed is positioned approximately where it would normally end up in the shell). I then tap the outside of the shell at the midsole mark with a screwdriver and take note of where that point is hitting my arch. I then mark that point on my foot with a pen. To double-check my mark I then use a marker to place a mark on the inside of the boot that corresponds to the midsole mark on the outside of the boot. (You kind of have to come up with a method that will work for your boot. My Flexons and Krypton allow me easy access to this section of the boot so it isn't that difficult). While the mark on the inside is still "wet" I put my bare foot back in the boot, make sure it is lined up properly, and then press it into the side of the boot. This transfers the marker line to my foot. I then checked that the ballpoint line (determined through tapping) and the marker line (determined through a visual line-up) match fairly well. If they don't something is screwed up.

4. Determine the distance from your boot midsole mark to the BoF position - Now that you have a midsole mark on your arch you can measure the distance to the ball of your foot. This certainly isn't exact science, but I just place a ruler on the floor and with my foot ON THE footbed I measure the distance from the midsole mark on my foot to the ball of my foot. For me this measurement is a nice even 60mm.

5. Mark the "new" midsole mark on your ski - With the measurement from the midsole mark to the BoF determined from the boot, mark the new midsole mark on the ski with a pencil. Measure back from the BoF mark on the ski and make a new midsole mark.

With my Volkls this new midsole mark was always about 30mm forward of the factory mark. On my Stocklis it is about 20 mm forward. Surprisingly, on my new Elans it's right on the factory mark.

BTW - I'm always looking for feedback on how to improve this process.

Marmot - good points. Please remember that no matter how much "testing" a manufacturer does to determine the midsole mark, that mark will still be based on an "average" size skier. Unfortunately they don't publish what their idea of "average" is. I'm short (5' 7") with small feet (26 to 26.5). With a shorter than average boot sole length the ball of my foot is going to end up further rearward than the "average" sole length when mounted at the manufacturer's midsole mark. That's why I usually mount more forward (usually about an inch or less).

My advice is to use either an Atomic or Tyrolia Railflex binding which gives you some adjustment for experimentation. The problem though with these systems is that you only get 3 settings, but you could adjust the toe and the heel fore/aft and get some additional groups of 3 different settings. I also use plates on many of my skis. The plates allow me to change the fore/aft placement of my bindings without re-drilling the skis.

So if you don't think your of "average" build it's probably worthwhile to investigate the effect of binding mounting position on your skiing.

I thought there might be some interest in the midsole mark adjustments I calculated for each of my skis:

Elan 2005 S12: 0.75cm
Elan 2006 M666: 0.85cm
Stockli 2005 Stormrider XL: 2.20cm
Stockli 2004 Stormrider DP: 2.50cm
Volant 2004 Machete FB: -0.50cm
Volant 2004 Machete Sin: -0.15cm
Volant 2004 Machete Soul: 2.15cm
Volkl 2003 T50 5-Star: 2.50cm

Positive values indicate that the midsole mark should be moved forward, negative values rearward. It's interesting that the Machete Sin and FB manufacturer marks are actually too far forward based on my calculations. You may see some threads about how most people hate their FBs mounted at the suggested position - most people mount them further rearward to improve the tip float. I remounted my Stormrider XLs for this season so that they are right on my calculated mark (22mm forward). I haven't mounted the Elans yet, but I think that they're close enough that I'm just going to use the manufacturer mark (and I'm putting a plate on the S12 so that will give me some adjustment if needed).

Marmot: What bindings are you mounting? If you're thinking Tyrolia or Atomic, I would suggest mounting them center and then using the standard adjustment on them. I assume youre thinking of using a Marker, Look/Rossi, Salomon, or other binding that does not have a center adjustment feature... If you are concerned about having versatility, you may want to look into one of those types of bindings.
Later
GREG

Hi guys,
F.Y.I. there is a new website in development as we speak that will focus on ski equipment testing aimed at more scientific bench testing supported by on hill testing. One of the topics for skis will be determining the reccommended mounting position for skis taking into consideration sidecuts, waist, flex, skier size, etc. to determine optimum mounting position.

I like your idea Noodler, of having a binding which had infinitly adjustable positioning of the binding on the mounting area of the skis. The Atomic binding 3 position is nice but having more incremental adjustment over a greater range would be awesome.

Bud:
What is the website?

Lou

Personally, I wouldn't. You are talking about making bindings more complex, more expensive, more likely to break, and less likely to do its job well without bending/twisting all over the place.

Modern system type skis are often very easy to achieve different boot positions with Marker Motions of recent vintage can be adjusted in 5mm increments without much work.

The variable position crap (ESS, later Atomic) had an annoying tendency to suck.

The various demo bindings that still allow individual discrete movements of the toe and heel can also move the boot position in fairly small increments, but they all tend to suck very hard from a skiability and reliability standpoint. Nothing sucks worse than bindings that aren't rigidly attached to your ski.

Perhaps if someone designed a system that used more than a stamped metal part and plastic to accomplish this I wouldn't object to it. I doubt you'd want to pay for it.

Also, there is the issue of the mounting points, which today are often not directly related to where the boot is. If you move the boot 2cm forward on a plate that is designed to float only at the rear, the results will not be that similar to moving that plate 2cm forward and leaving the boot where it was on the plate. I know this from experience. In many cases you can't actually move the plate anymore, but in the case of real race skis you certainly can.

I like the idea, I just don't think there is any way to implement it well for a reasonable cost.

For best mounting Position change binding, try out the VIST system (metal pins)

It has incredible stiffness, while still allowing you to move the binders. It is even used Sometimes in the Worldcup by people who cannot afford to have that many skis.
The system by Atomic is a bit soft the railflex somehow changes the ski flex too drastically.

One more thing to consider.

In pow it depends mainly on the steepness, snow condition and Turning length. Don't forget a single one of them when adjusting your Powder Skis. (hey Snowboarders might do this twice daily, if conditions change - finally skiers copy again)

I'm curious. Can you talk about this?

I also noticed watching WC DH races that the faster, stronger guys tend to be mounted father back.

Noodler:
you are right on track with your ideas of BoF and other variabilities. The average position marked by the manufacturer is just a place where the ski should work for most people. Doesn't mean it will work well, just work. Mounting too far back makes it a bitch to balance and the 2.5 cm you used on the Stocklis sounds about right to me. And yes ski tests are more about binding position differences than actual differences in the skis. Different manufacturers recommended position can vary greatly (easily by several cm). There is a reason racers and their coaches test for position and don't simply use some absolute recommendation from the designers. It simply is not possible that each skier should be mounted with their boot centre in the same place.

Regarding Mounts in Racing

As a disclaimer, I would say that WC racers mount themselves on the ski where they, their coach, and their ski tech feel that they are performing the best when on the snow. An interesting aside to theis conversation that I have heard of and noticed in talented racers is that they do not mind playing with the ramp angle of their bindings. If you think about it, it accomplishes nearly the same thing as moving the binding, but you are only adding or removing material from under the binding, or from within the boot. Bode Miller is a classic case of this. His boots are actually machined from the inside so that his heel sits lower than his toe. This increases the angle that his shin is at inside the boot, putting him in a more athletic stance. I do not know if this is still true to this day, but I do know that when he was using Dobermann's that he had them set up this way. I discussed this about two years ago with his team mate Erik, since at the time they were both using the Dobermann boot.

If you think about it, the ramp can make a huge difference in your stance if you assume that however your ramp angle adjusts your upper body stays in the same place. Without moving your shoulders or upper body at all, you can be given more forward pressure (ramping up the toe) or less (ramping up the heel). I experimented with this in my own skiing and found that I ski best with a flat ramp. I typically ski on Salomon bindings, which put you very far forward, so i machine new lifters for between the binding and plate that put the ramp at nearly flat, or just a millimeter or two higher in the toe. As far as obtaining more forward pressure: It works. Without moving your CM out over the tips of the ski, you can still have huge amounts of forward pressure due to the increased angle your shins are at. If you don't keep that angle however, and use the flex of the boot, it is easy to drift into the backseat... but if you are able to bring yoruself forward again you can really work the skis a lot more than with a forward ramp.

Later

GREG

I remember Bode acknowledging (when he was still in High School) that he needed his bindings on his various skis to be the same model, cuz he could tell the difference in ramp angles and his balance position on the skis when different-

Re: mounting positions: This summer, after a few days on her last year's skis, we moved a highly skilled 14 yr old girl to a 175 GS ski (mounted to race specs) - immediatley she was jacking at the waist and slamming the ski around - (it was ugly...) - that night I moved her bindings forward on the lifter plate (approx 1cm) and the next day, she skied fine and adapted as suspected she would to the fuller length.

I've mentioned this before in another thread, but since you were talking about "tricks" to modify the ramp angle of your bindings I thought I'd mention again that anyone with Look P series Lifter bindings can easily remove the lifter under the heel and leave the lifter under the toe for a 0mm ramp angle. Of course you'll need shorter mount screws for the heel, but this modification did wonders for my stance on my Machete FBs - it completely eliminated the tip dive feeling that comes from the default mounting point.

These exact same bindings are used with the Rossi T-Plate which actually has more lift in the toe than the heel. In fact I didn't come up with the idea on my own. I read about some racers that were doing this with their Looks. I highly doubt that the 6mm reduction in lift at the heel would affect the bindings ability to function within normal specs.

Ramp angles in bindings are modified frequently across many manufacturers to improve skier fore/aft stance. The adjustment amounts we're dealing with shouldn't be a problem for any of them. I wouldn't be worried unless we were talking about more than 10mm and even then it would only have a bigger impact on shorter boot sole lengths.

I should also point out that my shop did test these bindings and I doubt they even noticed the heel lifter was missing for their tests.

One of the reasons bindings are cheap is that there are very few parts held to tight tolerances. Modern bindings perhaps more so than older ones. Note how many parts are molded plastic.

Do it. I do, and find it quite worthwhile. My Fritschi Freerides are way up there, and the fave binding I've had yet on those skis.

I gained an additional 4mm (10mm total) over the normal 6mm by using a Rossi T-Plate below my Look P series bindings (this is my setup on my Stockli Stormrider DPs - they now have a 1mm delta). I also found out that the new PX series for this season can be mounted on the NX plates (maxplate) for more lift also.