Garage Mount your Dynafit TLT, Comfort or Vertical
Randonnee AT bindings

Homebrew backcountry skiing binding install tricks and tips

Disclaimer: By using these mounting instructions and templates, you agree to not hold Wildsnow.com, its owners or associates liable for anything. We provide no support or help with using these instructions -- you are on your own. If you have questions, please bring them up as a blog comment on our homepage.

By Louis Dawson

The fine-print packaged with Dynafit bindings says you should get them mounted by a pro with a mechanical jig. In my experience, while using a jig can save time, using careful measurement and paper templates can yield a mount equal to that of a shop-jig, if not superior. I've done dozens of mounts this way, and they have all turned out great. Instructions below are more specific to the TLT model, but work for the Comfort and other Dynafit models as well.

Warning: The paper templates sometimes supplied with Dynafit bindings may have screw holes marked inaccurately. These instructions are based on using a paper template you will download.

The keys to success in home mounting bindings are careful measurement, going slow, and using the paper template and your boots as a substitute for the mechanical jig used by a shop. Also, if you're new to ski work slow down and do a practice mount on a pair of dumpster skis or a 2x4.

What I'm presenting here is one of many ways a craftsman could achieve a good backcountry skiing binding mount. If you're comfortable with tools and measurements, you'll probably figure out a few variations along the way. Whatever you do, just remember the theme here is to center the bindings left/right on the ski, and locate the boot so it matches the boot location mark on the ski.

Here's how to do the deed:

For mounting Dynafit bindings you need a good workbench or kitchen counter with a straight outside edge. Cover your counters with something liked taped butcher paper, but leave the outside edge exposed. Tools and materials needed:

• carpenter's combination "tri" square
• carpenter's 24 inch framing square
• handheld screwdriver with pozi-drive bit to fit screws that come with the binding (with care you can use a jumbo philips bit, but pozi is much better*.)
• electric drill with sharp 5/32 inch bit or special ski bit (see below*)
• electrical tape, clear office tape, masking tape, and of course some duct tape
• sharp center-punch, with associated hammer
• straight steel or plastic "yardstick" type ruler
• tape measure
• fine point Sharpie type marker
• 1-hour epoxy or synthetic wood glue
• paper jigs packaged with Dynafit binding, or the Portmann super template
• scissors, blank paper and paper punch

Step 1 Make sure you know where the mounting mark (aka "sole midpoint") is on your backcountry skiing boots. It's usually a small vertical line, arrow, or triangle molded into the side of the sole about midway between heel and toe. If your boot doesn't have it, compare to another boot of the same size that has the mark, and transfer the mark. Or, as most of these marks are simply half the distance between toe and heel, just locate it by measurement. Enhance the mark with your Sharpie so you can't miss it.

Step 2 Align your skis so they are parallel to the edge of your work bench. The idea is that an imaginary line drawn down the center of the skis would be close to parallel to the edge of your bench.

Next, double check that the skis are exactly next to each other in length, by again holding a straightedge against the tails. When you're happy with your arrangement, draw some small reference marks on the skis and bench so you'll know if they get moved, perhaps tape the skis to your bench with duct tape.

If you're in doubt about this, simply make center marks on the tip and tail of the skis, and locate these marks equidistant from the bench edge, so you have them close to perfectly parallel. But don't obsess on this. The idea is to be able to use a carpenter's square to make a reasonably perpendicular mark across the ski, as shown in photo below.

Step 3 Find the boot mounting mark on the skis; usually a small triangle or line that's at the approximate midpoint of where you'd imagine a boot sitting on the ski. Be sure you get the right mark -- if in doubt ask a shop rat, or call the ski seller. Grab your framing square (now you're a carpenter). Using the edge of your workbench as a straightedge for the square, draw a set of nice black lines across the boot position marks, so you have a good visual reference. Now you know why the ski centerline needs to be somewhat parallel to the edge of the bench. The idea is that by using the edge of the bench for the square, you can scribe lines on the skis that are close to square with the long axis of the skis -- thus giving yourself excellent reference marks.

Step 4 Set a boot on a ski, and align the mounting mark on the boot over the mark you just made on the ski. I usually eyeball this. If in doubt, make a small square out of cardboard and use it to reach up from the ski to the mark on the boot. Take care that you get this somwhat exact -- to the nearest millimeter or so.

Step 5 Now your boot is sitting on the ski where it'll be located once in the binding. Move your operation to the toe of the boot. Set the combo square on your bench, and use it to transfer the location of the binding pivot "pin" point down to your workbench, or simply mark on the top edge of the ski.

"Binding pivot point" simply means the center of the steel dimple built into the toe of the boot.

Again, move slow and take care to be accurate. While large mistakes can be rectified by drilling a few extra holes in your skis, small mistakes are hard to fix, as new holes will overlap the wrong ones.

Step 6 Remove the boot from your ski.

Using the same framing square technique you used to mark the boot location line, scribe a nice black line across the skis, matching the pivot point you marked in step 5.

Before doing this, triple check that your skis are still parallel to the edge of your bench, as you want this line to be perpendicular to the long axis of the skis.

 
Step 7 Now the origami begins. Dynafit user Bob Portmann was kind enough to create a super accurate paper template with center lines (and other layout lines). Download template here (it's a PDF that requires Adobe Acrobat Reader). Print the template, and make sure it prints at 100% scale and that your printer doesn't change it from 100% scale. This is easy to check. Print a template and simply set your binding on the paper, if the holes line up you're good, if not, play around with your printer settings. When printed correctly this template is a joy to use -- it's dead-on accurate. We'll host the Portmann template here, and make any updates that are necessary if the bindings change or we think of ways to improve it. Portmann's template works best using a longitudinal (tip/tail) center line you draw on your skis. Used correctly, it'll result in a mount that's more accurate than a mechanical binding jig. Thanks Bob!

(As near as I and others can tell , the actual physical hole dimensions of the Dynafit binding are: On the toe piece, the 4 hole pattern is 30mm X 26.5mm and the front hole is 18mm. On the heel piece, the hole pattern is 32mm on the front holes, 36mm on the rear holes and 52.5 mm between front and rear holes. If necessary, verify all with calipers.)

A. Make super-accurate center marks/dots (left/right) on your skis, about 12 inches for and aft of your binding toe and heel unit locations. These marks are important so take your time. You can make left/right center marks by eyeballing a ruler and double checking, using a drawing compass to measure from the edges is a good method as well, but our favorite is to simply use folded paper:

To find center using paper, simply wrap a strip of paper around the ski, crease it over the sharp steel base edges, remove and fold in half using the edge marks as reference, then place back on ski and use the crease to locate center. While simple, work carefully (mainly, mark the spot on your ski where you place the paper, as moving it towards the tip or tail will throw things off because of the ski’s varied width.)

Connect your left/right center marks with a your yardstick and draw an accurate line using the edge of the yardstick as a guide. The idea is to create a long mark down the center of each backcountry ski in the binding mount area (in the tip/tail direction). Be sure this mark is long enough to go well past the mounting area of both front and rear binding units.

B. Center the paper template by aligning with the center marks you drew on your skis.

Using strip of paper to find left/right center of ski.

Step 8 Once you've centered the template and have it in correct front/rear position, tape the toe unit template to the ski. The trick here is to align the pivot point line on the paper to that you marked on your ski, then accurately center using the marks you made using the methods described above. Take your time, and tape securely to the ski (leave the ends of the centerline visible so you can check for movement off alignment.)

Skis with toe template located, ready for the center punch.

Be extra careful to point the template in the correct direction. An arrow points towards the ski tip.
 
Step 9 Now the moment of truth. First, use a sharp finely pointed object to divot the paper template on the exact screw location marks, this mark helps locate your center punch by feel, as center punches are sometimes too thick to visually locate (thanks goes to Jonathan S. for the tip). Next take your your sharp center punch and lightly dimple the ski at the exact center of the screw marks. Remove the paper jig.

Notice that the hole pattern for the toe unit includes one forward mark/hole that's centered on the ski. Before drilling, make sure your center-punch mark for this hole is on the tip/tail centerline you drew on the ski. Check the other marks as well, and make sure they're equidistant from the edges of the ski.

Once you're sure the marks are where you want them, center punch the forward hole with a harder hit from the hammer, to make sure your drill bit doesn't wander when you drill. Leave the other marks alone for now.

(Remember: Measure twice -- drill once.)

Step 10 Ahhhh, now, power tools! Chuck that sharp bit in your drill. (Using a sharp drill bit prevents the bit from wandering sideways while you drill.) Place a screw in the binding (with the plastic shoe that goes under the toe unit) as if it were already in the ski, and use the protruding screw as a gage to to figure how deep you will drill. Tape a depth stop to the bit by wrapping tightly with electrical tape to create the stop. Drill the marked skis with minimal pressure, so you don't mash the bit through a ski. Remember, only drill the one front hole at this point, and be clear that you're only working with the toe unit at this point, the heel heel comes later.

If you do totally klutz it and drill through a backcountry ski, it's actually not that big a deal (repair with epoxy and P-tex), but it's considered poor style -- to say the least -- and is none too good for your kitchen countertop. By the way, if you got the brakes for your backcountry skiing Dynafit bindings, put them on after you've done the mount, as they make it harder to work with the bindings.

(We recommend using drill bits specially designed for ski binding mounting, see bottom of page for more information.)

 
Step 11 Screw the toe unit onto the ski, using only the front/center screw in the one hole you've drilled. Snug down the screw but don't tighten aggressively, as you'll be removing it again, (don't use a power drill to torque screws unless you're a tool ace). Remember the plastic shoe that fits on the base of the toe unit. Snap the boot in the binding toe. Mark a center line on the heel of the boot with your Sharpie, below the metal binding fitting, using the center of the screw as a reference.

 
Drop the heel of the boot onto the ski, and center by matching with the tip/tail center mark on your ski. (The idea here is to get the boot heel and binding toe-unit centered on your ski, mark everything well, and be able to keep rechecking it.)

Keep the boot centered, and very carefully unlatch the toe unit and remove the boot. Study the punch marks you made on the ski for the remaining four holes. Do they line up close with the holes in the binding? If so, remove toe unit, center-punch the holes a bit deeper, and drill the holes in the ski. If they're off more than a smidgen, place the boot back in the toe, re-center heel, and repeat checking the alignment. Sometimes the combination of boot machining and whatnot results in the holes needing to be drilled slightly off (never more than a millimeter or less, in my experience). Recheck several times. If you're still sure your punch marks are off, re-punch, re-check, and drill the new marks once you're happy with them.

Step 12 Again, screw the Dynafit binding to the ski with just the forward center screw. Snap in the boot, drop the heel on the ski, center the boot, and remove with care. Study the holes. Several will usually line up perfectly. Run the screws into those first. Don't heavily tighten the screws as you'll be removing them again later. Again, snap the boot into the binding toe, drop the heel, and use the boot as a lever to nudge the binding so that the heel lines up with your center mark (while you do this, pull the front tab up to lock the binding in touring mode, so you can thrust the boot side-to-side without it popping it out of the binding). Keep repeating this process until the screws are tight, and the heel is lined up -- well done equipment is essential for safe and successful backcountry skiing!

The process is all less tedious than it reads -- but don't skip any steps if you want successful backcountry skiing!

CLICK HERE FOR PART TWO -- MOUNTING THE DYNAFIT HEEL

*(Drill bits: Ski shops use special drill bits for drilling skis, usually 4.1 mm for skis with metal layers, and 3.5 mm for skis without metal. If you mount a lot of backcountry skis, it's a good idea to buy some special drill bits from an outfit such as SlideWright, along with such bits, buy a threading tool (tap) to thread the holes. In my experience, it's okay to use the slightly larger 5/32 inch drill bit as suggested above, without a tap. If you do so, especially with non-metal skis, just be careful as you twist the screws in so you don't over-tighten them and strip the holes, and use epoxy in the holes since they're slightly oversized. (to remove epoxied screws, lightly heat with soldering iron before twisting out). Pozi screw driver bits are also available from SlideWright, and highly recommended.)