(Editor’s Note: This is a telemark tinkerer’s system which resembles the commercially available Telemark Tech System® but only in terms of using a Tech Toe. Just about everything else is modified within the limits of a zealous but amateur home workshop. Ben did an outstanding job of creating his own version of a telemark binding using tech toes but some of the conclusions or references to TTS should be understood as creative variations but are not representative of the Telemark Tech System® sold by Olympus Mountain Gear.)

Like many telemarkers I was skeptical of the Telemark Tech System (TTS®) when it was unveiled at the 2011 Outdoor Retailer Winter Show. Being familiar with Dynafit bindings, I knew that the tech toe piece couldn’t be as robust as a standard telemark binding. By removing the heel it was essentially emasculated, becoming a flimsy toe attachment with no controls. Little did I know how two little pins could be so much more. Once the gears were rolling it was only a matter of time before I started to tinker with my own version.

I mounted my first set of tech-toes on Dynafit-telemark shift plates. I used the extra telemark mounting holes behind the tech toe mount to locate the hold downs for the heel assembly. I made the spring assembly hold down (fulcrum) from a polyurethane shim (cutting board) reinforced with aluminum channel and I used a steel pin as the pivot point. I added a riser (more cutting board) to the Dynafit toe to improve clearance between the boot sole and the hold down, and to equalize rocker induced heel rise.

Round 1
My first version of a home-brewed TTS used the expansion cable springs from Voile’s three pin cable binding. Despite the older design, the expansion cable spring wires worked surprisingly well, providing decent spring travel and better retention than expected. Being light weight and having a convenient side closure, this style of retention shows promise in combination with a tech heel because it might allow both telemark and AT capability in the same rig.

Round 2
For round two I tried the Hardwire cartridge assembly. As expected it provided more lateral control and more activity (retention) than the expansion spring wires — similar to HH position 2-3, but still not as much as I’d hoped for. I had compromised on the fulcrum position, placing it 65mm from the tech pins to prevent maxing out the cartridges too quickly. Given longer cartridges with more spring travel, I think the fulcrum could be moved rearward an additional 5-10mm to increase activity.

A unique challenge with tech toes is that forward rotation of the boot toe is not limited by a toe box/bale, as a result it takes significant heel retention and spring travel to effectively control the boot. The real surprise was that the Dynafit toe piece held the boot much better than I’d anticipated, though I did switch it into tour mode to minimize release.

Though TTS worked better than expected I still wanted it to be more active and have sufficient ROM while under power to be a viable option for low-stance tele-skiers. The Axl’s long, stiff springs seemed liked an ideal match for that result.

Round 3

Since the Axl allows more spring travel I moved the fulcrum back to 75mm between fulcrum and tech pins (nearly identical to ‘beta’ version of TTS®). I removed the cable and spring assembly from the Axl and threaded the cable through the hold down. Unfortunately the cable was too long, barely providing any preload even with a mondo 30 boot. On the carpet it felt like HH#3-4. On snow, however, it felt like barely any retention at all. I was dumbstruck – it felt so solid on the carpet. Clearly my implementation of the Axl cable system needed further work.

Round 4

Over the summer I let the TTS ideas fade until early Fall when the bug bit again. It seemed what was needed was a way to mount the Axl cable assembly to incorporate the moveable slick pin and flex plate, this would improve the cable run and allow for a more rearward hold down. I had an idea to use a channel, not unlike the NTN frame design. As luck would have it, a friend provided some binding mounts, which, with minor modification allowed me to mount the entire Axl spring and heel assembly, from the aluminum cable retainer rearward.

In contrasting the two Dyna-Axl bindings, note that both bindings have about the same sole angle and spring compression, but the revised binding has a more forward cuff angle, greater bellows flex, and a more rounded ball of foot. I believe this is due to the flex plate allowing a fulcrum further back. Small changes can make a big difference.

An early cold snap had our local hill open in November, so it was to the hills of North Carolina that I went, Dyna-Axl in hand, just one week before Thanksgiving. The white ribbon of death was looking good all things considered, crowds were few, and the snow was firm corduroy, narrow, fast and smooth. I set the Axl slick pin in position one (least active) and started making turns. Not bad at all. Action was smooth, retention similar to an HH#4-5.

The most amazing part was that it worked so much better than the complete failure of the previous Spring. On my second run I skipped to position three (most active). Quickly I realized that this was far too active for early season turns, it felt like my heels were tied to the skis, it literally made my tips auger into the slope. So I backed off to position two (medium activity) and took a third run, and the rest is history.

In position two the Dyna-Axl bindings were still quite active, equal to an HH position 5 with stiffy springs, which is a bit much for many skiers, but just the way I like it! I proceeded to take a number of runs to get the feel of the system. Then it dawned on me: it worked, the darn thing worked! And not only did it work, but it worked incredibly well. It was as smooth as any binding I’d ever skied, it had a modicum of release, brake potential (available with La Sportiva and ATK tech bindings), it was lightweight, it had three effective levels of activity, and because there’s no toe box, there was no toe crunch or bellows collapse. I skied for three hours that day, made hundreds of turns, and it felt great!

The real proof came at Thanksgiving when I skied three days at Brighton in Utah. It was early season conditions with thin cover, but a good base allowing for fast groomers top to bottom, some mild bump action, and a little fresh in the trees. The bindings performed amazingly well. Over a three day period I did nothing more than adjust the preload as the Axl cables and springs stretched out. I maintained the binding in position two and skied them hard. I suffered no releases, no pre-release, and no failures. I give the Dyna-Axl Two Thumbs Up!

More nitty gritty details on page 2
© 2011

The Nitty Gritty:

Activity:
How retentive is my home brewed TTS in terms of ball of foot (BOF) hold down, resistance to heel lift, etc.? Comparing the Dyna-Axl to the Hammerhead (HH), both outfitted with standard springs:

The activity level of the Dyna-Axl is not only more than I expected and more than a standard Axl, but the action is very smooth and comes on as soon as you lift the heel/push the cuff. I did not ski the Dyna-Axl with the pin removed, but in carpet tests it had a very neutral feel, on par with a Switchback or 7TM.

Touring Function:
In order to use the free pivot, the heel throw must be “stowed” behind the heel riser. This can be done with skis on by simply squatting down and flipping the lever off the heel, lifting the climbing bar, then slipping the heel throw over the back of the riser. The tech toe is a true free pivot, minimal resistance while skinning means less energy expended, getting in and out of the toe is as simple as flipping the release lever with a ski pole tip. A full 90° ROM for touring is available, even if you never really need that much.

Lateral heel displacement:
How far does the heel move across the ski under lateral pressure?

This is an area of concern voiced by many interested in TTS. At first glance it would seem that the tech fittings would be insufficient to contain the boot during a hard telemark turn, but this could be no further from the truth. I weigh 200#, driving mondo 30 boots, skiing very low and very fast. As an acknowledged binding breaker, you would think that I’d be blowing out of the toe on every turn, but after hundreds of turns I never had a wiggle. In truth, the tech fittings work in telemark for the same reasons they work in alpine touring, it’s a good design.

Durability:

Can the tech fittings and pins take the abuse day after day?

With TTS still in it’s infancy, I can’t say how long the fittings and pins will last before they wear out or fail, but in alpine skiing the tech system has proven itself durable over the years and has become the standard by which other lightweight AT bindings are compared. According to Mark Lengel, his TTS bindings have been skied for multiple seasons with no signs of excessive wear outside of what would be expected from AT use.

Release:
The Dynafit tech binding is a system binding designed with a simple pincer toe that relies on a heel piece for stability and to set both lateral and vertical release. TTS incorporates only the tech binding toe piece, so lacking the tech heel, there is not an adjustable release per se. In ski mode, without the heel engaged, the tech toe piece releases easily, hence my use of the binding in “locked mode” (touring). Lateral stability would seem to be a problem for TTS, but in reality the heel throw and spring assembly provide for some of the missing stability, though less than with a tech heel piece. In bench tests I found that the Dyna-Axl in ski mode (unlocked) would release laterally with about the same effort as a complete Dynafit binding set at a DIN 5. In locked mode the Dyna-Axl took more effort to release depending on the number of “clicks” that the toe piece was engaged, approaching DIN 10.

This short film clip shows the release function in ski mode ~ DIN 5:

In tour mode with the lever locked the release requires significantly more effort, ~ DIN 10.

There are tech bindings that have an adjustable release toe piece (La Sportive, ATK, Plum), but the cost for these bindings is double the Dynafits, so there’ll be no tests forthcoming for this budget garage tinker; plus my wife said no. That said, the Dynafit toe has an acceptable disaster release option for use in avy terrain or when protecting injury prone legs. Additionally, I found the Dynafit toe was quick to re-center when incompletely released, which is a nice trick in case you induce a partial release. I did not get the sense that the system would pre-release any more than  other releasable telemark bindings, but I do believe that the release will be better and more reliable, especially in a twisting fall. I did not ski the binding unlocked since I did not want to release too easily.

Forward rotation and Retention Fade:
My early TTS set ups with the hardwires and spring cable wires did a good job of limiting forward rotation to the point where the boot was ~30 degrees to the ski, but beyond this point it seemed as though binding activity “went away”. In non-engineering terms; I am not an engineer, this seems to be due to the boot arc maximizing spring length early on (zero to 30 degrees), then as the boot continues forward past the peak of the boot arc, the optimal angle of retention is diminished and the springs become less capable of controlling rotation. In contrast, the Dyna-Axl provided continuous retention (activity) throughout the boot arc because the cables are continuously leveraged by the boot, providing a progressive feel, from heel to ski to knee to ski.

Cable Pivot point:
The real meat and potatoes of TTS, lots of variability here to optimize the feel. I can’t say enough about the three settings I adopted from the Axl, at 70mm, 80mm, and 90mm from the fulcrum to the tech pins. These settings provide the ideal mix for me as I could see using the third position for racing gates and carving, the middle position for all around skiing, and the first position for softer snow. There is also a zero position with the slick pin removed which I could see being useful for softer boots, smaller skiers, and Nordic styled skiing. What I did notice is that the “optimal” fulcrum position seems to vary depending on the retention system used, so a different spring assembly might need more or less distance between the pins and fulcrum to optimize activity.

In summary, I found that my Dyna-Axl variation of the Telemark Tech System works, and it works well. There remain issues to be resolved such as optimizing retention and fulcrum position, developing TTS specific tech toes that provide for adjustable release, and providing binding kits that allow a non technical person to assemble a telemark tech system. By utilizing the tech fittings, TTS avoids the complications inherent in having a toe and heel that are co-dependent, allowing for a multitude of retention options and a free pivot that is unencumbered by the means of retention.

It’s a sweet trick, that’s for sure 🙂

© 2011