Telemark Talk / Telemark Tips Forum

I just received my Rottefella Magnum NNN BC manual bindings and skiis in the mail (Rossignol BC 80). I'm going to attempt to install my bindings myself using the included paper pattern (stop me if this is a bad idea) and it will be my first time installing any ski binding, so I am trying to make sure I do it right.

I did notice that there is an odd shim or peice of metal with an eyelet in it shown in the manual and in some but not all pictures of the binding online. This item was missing from the box and I am not sure if I should move forward with installing the bindings or return them to where I purchased them and ask for a new set.

My questions are:

1. What the heck is this thing used for?

2. Can I install the bindings without it?

I've circled the metal item in question in the attached photo from the manual that came with the bindings and also a photo I found online. Again, not all photos of these bindings installed seemed to include this peice of metal.

Can't help you with that mystery, although you've made me curious. I've got Magnums in my mother's suburban basement to mount, but I'm 50km away in my tiny city condo.

Don't sweat mounting them. I've mounted NNN BC Automatics twice; also Voile 3-pins twice. Yes, 'measure twice, [drill] once.' In the end, I found 'TLAR' ('that looks about right...') more effective. Once I got the bow-most screw seated loosely, I could adjust to get the two behind it in the perfect spot.

Good luck.

It's for a leash. I haven't had a pair include them in many years now. They seemed to have dropped away.

Also the instructions will tell you to pre drill 14.5mm or something egregious. This is for old bindings that had longer screws. Don't do it. I think 9.5mm is plenty, check the screw length. (I'm not home right now)

This binding can sometimes wander when installing. A clamp on the flat part (rails) can help keep things steady. Start with the nose. Make sure everything is seated flat to the ski when you are done.

Ahh, for leashes! That makes sense. I didn’t know leashes were even a thing for these skiis so I think it will be fine to leave them out.

And regarding the ski install, I’m understanding that you should drill the first hole in the front and loosely install the screw and then clamp the bindings down and use the other holes as a “jig” to guide the drilling of the rest of them? This is opposed to using the paper pattern to drill all of the holes before attaching the binding?

I was sad to see that the directions and videos online showed the use of a purpose made jig for this task. Obviously I don’t have such a thing nor do I install bindings often enough to justify the purchase. If it’s necessary to have the purpose made jig I’m better off driving them to a shop that can install them for me. But I do like to do things myself if I’m not at a high risk of botching the job.

I have installed several pairs of these bindings.
Before starting, I looked for a jig to buy, but was not able to find one.

I am not a "well, that's good enough" sort of person (in other words, neurotic, OCD, perfectionist, ...)
I always stress out about drilling holes in skis, and did once really make a mistake, but life goes on.

To mount the bindings, I:

1. Put tape on the ski top sheet, where the bindings will mount;
2. Mark the balance point of the skis (they will likely be different between the two skis, so I average the located between the two skis);
3. Mark the centerline of the ski in front of front screw and behind back screw;
3.a. (Measure center of ski referencing the base of the ski, not the top or sidewalls of the ski);
4. Using the above two marks, draw a straight line down the center of the ski;
5. Tape the paper template to the ski, lining up the balance point marks and centerline marks that are on the template with the marks you have already made on the tape applied in step #1;
6. Use something with a sharp point (awl, center pinch, pointy knife blade) to mark (indent) the drill locations;

- I then use a small drill bit (1/16") to drill the first holes (be sure to tape the drill bits so you know the proper depth, i.e. when to stop drilling.
- Compare depth marked on drill bit to the ski to visually confirm that you will not drill through base of ski).
- Sometimes (often) the first holes I drill are not exactly centered in the location marked on the paper template.
- By using a small drill bit first, I am able to adjust the final hole to be closer to the specified location.
- I usually use progressively larger bits before drilling the final hole.
- The fiberglass strands in the ski layup tend to push the drill bit off location, so the above is how I work around this. With a jig, the drill bit is locked in the proper location and can't wander.
- Also, be careful to drill the holes square to the ski surface -- it's easy to tip one way or the other when doing this by hand.
- I also use a countersink to VERY slightly campher the final hole, so that there is less bulging of the top sheet material when the screw is inserted (this is quite optional).
- It also helps to have the proper #3 PoziDriv driver bit to install the screws. A #3 Phillips will work, but you must be very careful to not let the bit spin out on the screw head.
- I then use a wooden match or toothpick to work polyurethane glue into the screw hole. You don't want to fill the hole with glue -- just make sure the inner surfaces have a coat of glue, to seal the wood from moisture. If the hole is full of glue, the screw will compressively force it into the ski core and might possibly case delamination (maybe I'm just making this up, but it seems theoretically possible).
- When tightening the screws, I progressively tighten them, going around a final time to make sure they have reached the point where they stop turning, at the same time, being extra careful to not strip the screw out -- it's a by-feel thing gained by tightening lots of screws.

I don't mean to make this sound intimidating or beyond what you can do, just trying to point out the details to pay attention to.

Or, have someone mount them for you. If you do, I would first confirm they have the proper jig.

Stephen wrote: ↑

Wed Oct 13, 2021 4:20 pm

[...]
3. Mark the centerline of the ski in front of front screw and behind back screw;
3.a. (Measure center of ski referencing the base of the ski, not the top or sidewalls of the ski);
[...]

Hi Stephen,

Right here at the beginning is where I usually have trouble. How do you mark the center of the ski using the base of the ski for reference? Do you use a tool to find the center?

I liked your detailed write-up.

Scott.

Calipers?
Two square sided blocks, one on either side, and measure?

Sort of a difficult process, but doable.

But, you made me look...
And I found this:

Don't know if the legs are long enought to reach down to the ski base.

It seems like one could make a jig like above.
It wouldn't be perfect, so mark one way, reverse the homemade jig (side to side) and mark again, this gives a second line, parallel to first line and center is exactly in between. Wish I had thought of this sooner!

To find the centre line of the ski I run a piece of tape laterally at two points fore and aft and running the tape down the side of the ski .Next carefully trim off each side of the tape pointing down along the metal edge. Open the residual tape out both sides while still stuck to the ski. Measure the length divide by two and mark your centre line.

To be precise on centerline, measure edge to edge. Although I am a proud America the metric tape is better for this. Flip the ski to the top side, put a square to the ski edge, use a sharp pencil and make a mark at the center line.
You are not building a church!
I’ve held tolerances to -.0001” (no there is not an extra zero there) in a tool shop to -.75” pouring foundations. I’ve never seen uptight help hold a tolerance.
My best advise is to use a fine center punch on the paper template, followed by a bigger punch. Also if you get nervous walk away, breath. Any operation that can be easily completed by using a paper template and a hand drill doesn’t need to be complicated by Chinese arithmetic.

I like @Nick BC's idea!
Can't get much more simple than that.