Head Binding Placement?

[Bearmani]

As I have just recent bought a pair of Head Monster iM 72 in 170 cm, I thought that I would check the "ski technical balance point" versus the manufacturer's ski mounting mark. For the technical balance point, I used the same method printed on the Campbell Dynamic Balancer PDF file on realskiers.com. Am I mistaken that the technical balance point appears to be almost 9 cm forward of the manufacturer's mark?

I'm interested in the answer because my previous Volkl skis were mounted using this method and the difference was much less. Also, I haven't mounted my Railflex bindings onto the new Heads. If anyone has looked into this issue, I'd be interested to know if I am correct.

[Jim Ratliff]

Bearman:

Don't mount the binding 9 cm forward, it's too much.

Sounds like you are measuring apples and oranges when you want to be measuring oranges and oranges (or maybe apples and apples). The manufacturer's mark indicates where the midsole line of the boot is supposed to be. Peter's approach determines where the ball of the foot is supposed to be. The difference from the midsole line of the boot to the ball of the foot may be 3-4 inches (7-9 cm) just because of the change in reference point (or more if you have big feet).

You should focus on where the midsole of the boot is (relative to the mark on the ski) WHEN the ball of the foot-boot location is over the "technical balance point".

I have done this same measurement on my iC160's and more recently on my iM77's (railflex bindings on both). In both cases, Peter's "ball of foot over mid-point of running surface" indicated a location where the midsole of the boot would be between 15 and 20 mm forward of the Railflex 0 position. So I just take Harald's advice and ski with the railflex in the +15 position most of the time.

I even had a person recently ask me why I had silver lines marked on the sides of the soles of my boots and on the sides of my skis. It's my ball of foot mark on the boot and center of running surface on the ski.

[Bearmani]

Jim, thanks for the information on how the manufacturer's center mark relates to the boot. If I account for the difference between my BOF position and the boot midpoint, it turns out that I would still be a little more than 4 cm forward of the ski midpoint with my small 291mm sole length.

[Jim Ratliff]

Bearmani:

That's really interesting. I hadn't really pondered much about the impact of longer vs. shorter boots. My boots are 315mm, so yours are 24mm shorter than mine. Half of that is in front of the mid-sole (half behind) so it's reasonable to 'assume' that you ball of foot is 12mm farther back then mine.

Anyway, assuming that the Railflex plate is came pre-mounted on your iM72 (I don't know if it even comes flat) here's what you could try. It is actually pretty easy to slide the bindings off of the rail and change where the toe piece and heel piece attach to the connecting bar. Consider moving the toe and heel piece +15. That way when the screw is at +15 you will really be at +30. When the screw is at -15 you will really at 0.

Note that the numbers on the connecting rail are doubled. So, your toe and heel piece are currently attached at 290. Change the toe piece to attach at the 320 number (this is really only 15mm). Change the heel piece to attach at 260 (if it goes this short, I can't remember). While the numbers take some thought to understand, this is effectively a +15 on the connecting rail. Then you slide the bindings back onto the rail. Now the zero is really +15.

One of the joys of the railflex setup is this flexibility to decide whether you really want to go 3-4 cm (30-40mm) forward without having to drill any holes in the ski.

DISCLAIMER. I am not a ski tech and don't have any money or insurance, so play with any of the above at your own risk and reward.

[Bearmani]

While I appreciate the liability disclaimer, it won't be an issue. I purchased the skis and bindings separately. The skis are actually flat. So, I can mount the LD12 Railflex II "almost" anywhere on the ski that I please. Now, I just need to talk to my local shop guys to see if they are willing and capable of mounting these bindings in the way that I am thinking. Thanks for the information on the marks.

[Ken]

I demo'ed the i.M72 170s. Fine skis. My 325 mm boots were set with the boot marks 1.5 cm forward of the ski marks, and they skied great.


Ken

[Stormin]

One of the key points on the Railflex bindings is that you have adjustability to .5cm. Not only can you move the binding on the rail, you can also adjust the toe and heel (by removing the binding, e.g. from 335/335 to 345/325 moves the binding forward 1cm when the binding is set at 0).

This gives each individual skier the ability to fine tune the ski to their liking. I?ve done this with 3 or 4 different Heads (and other ski mounted with a railflex) and I?ve found it an amazing way to fine tune each ski.

Stormin

[Jim Ratliff]

.... 335/335 to 345/325 moves the binding forward 1cm when the binding is set at 0).

Stormin:

I agree with everything you said except your example. The numbers on the toe and heel piece are both numbered twice as big as the real distance. For example, to go from a 320 boot to a 330 boot you move both the toe and the heel from the 320 number to the 330 number. This means that, in reality, the toe and the heel each moved only 5mm to get the total increase of 10mm longer boot. the numbers are designed to make it easy for the ski tech to get the correct setup for a given boot and not really like a ruler. So, your example above really only moved everything forward by 5mm (1/2 cm).

As far as the flexibility and ability to fine tune the balance, I agree whole heartedly with what you said. I think the Railflex is a wonderful setup.