Binding cable repair- A DIY universal field repair.

Simple DIY binding cable repair to allow a Telemark skier to ski back to base or ski for a week after breaking a binding cable.

Introduction

I have previously reported on field repairs to my ‘resort’ 7tm bindings with alpine tour pivot pins. Now I confess to having my second cable break on my much lighter Reva Rottefella bindings that I use for my backcountry telemark skiing on remote ski slopes (They are so old that they are no longer listed and spares are no longer available). “I can just hear people saying that I must be hard on my gear. I think this is not the case. I do use my gear a lot and keep it for a long time and it simply wears out or corrodes in hidden places.” A rusting cable inside a plastic sheath material was involved in the last two cable breaks.

I love the lightweight Reva binding for backcountry telemarking, but I am told that they are no longer made and replacement cables are difficult to find. “I did have my last spare cable (at home), but I did not take it with me on my first ski trip for the season.”

So I had myself to blame when I had my second cable break as we were skiing homeward. I hate walking on snow and the snow surface was a very hard frozen and rutted one that did not let me use my usual trick of Telemarking home on one ski. Consequently, I decided to put my field repair contingency plan (dreamt up over some time) into action to see if it worked in reality.

I see that someone else has reported on a similar temporary field repair for a broken duck bill when using a three-pin 75mm binding without a normally fitted cable. So I am not alone in my madness. Also, my suggested fixes should be applicable for the broken duck bill situation where a binding cable would not normally be in use.

I thought my solution may interest others who hate walking on snow and may find themselves in a similar predicament when a long way from other help.

It may be a helpful temporary repair idea for all other cable bindings and even for duckbill bindings without cables. My eventual repair kit I think is universal. “So if you don’t want to read all the intervening crap please go to Part 3 at the bottom of the post. On the other hand, you may wish to read the crap as it describes an evolution of repair ideas that may come in handy for you or your mates in the backcountry one day.

The function of a telemark binding. This is probably a gross simplification for many Telemark experts. “So accept my apologies in advance.” The most important function of a telemark binding cable is to hold the boot duckbill into the corresponding toe piece of the binding. Some even use a cable to supplement the three pin binding.

Tensioners devices allow for the cable tension to be adjusted to hold the duckbill firmly in the binding and springs within the cable loop stretch and allow the heal to rise during striding and Telemark turning.

“In support of this conjecture, I remember successfully Telemarking down a slope with a broken binding cable, while carrying a big load of beverages in my backpack. It was our first night out for a week-long trip and with fading light, we went out on a special mission to collect a cache of liquid refreshments that had been ‘planted’ during Autumn.

With a substantial, precious, dense liquid load in my backpack we skied down a lovely slope and a sharp snap sound told me that my Achilles or binding cable had broken. Undeterred, with my precious load on my back I finished the run with a flourish of Telemarks in the deep fluffy snow. I pressed the duckbill forward into the binding at all times. Then I announced to my accomplice that I had broken my cable on our first day out.”

When a cable breaks in the field, it is difficult to make a quick and strong join in it to repair the binding whilst maintaining the convenience of the original cable’s length adjustability and spring relief actions. “Anything that allows me to keep skiing is worth a try.”

The temporary cord trick was used to quickly get out of immediate trouble and deliver the precious load. Then, back at camp, we conjured up a more substantial repair. This repair lasted for a week of very active Telemark skiing in heavy falling snow and happily carried me back safely to that other world where normal people live.

This repair has inspired two more substantial repair methods described below: Part 2. Better temporary repair and Part 3. Universal binding cable repair kit. This repair: Part 1. The quick binding cable repair can be made simply from some strong cord, but the preparation of the cord with critically spaced hitching knot and melted and thinned ends will make all the methods very easy to implement on the snow while skiing. I used 3.5mm nylon cord but subsequently found that a 6.5mm polypropylene cord was a tight fit but very much stronger, less stretchy and less prone to abrasion damage.

Part1. The quick binding cable repair

A piece of strong cordage can be used as a substitute for the cable and can be loop hitched to the remnants of the cable (to keep it tidy). Then the cord can be tied behind the bulges of the main springs, with a clove-hitch that is backed up with more hitches (As shown in the photo below).

If no such spring bulges were available on a particular binding, the cord could just be continued to be anchored on the opposing sides of the tensioning cam lever pivot points.

The last clove hitch attachments on either side of the binding formed the load-bearing points in the tensile loop. This means that they bypass the stretching relief that is provided by the springs. However, I found that there was sufficient ‘give’ within the cord for the binding to function quite well with a normal Telemark heal lifting stance.

One of the terminal clove hitches was easily adjusted to provide a nice firm engagement of the tensioning cam at the heel of the boot (after an initial tensioning and stretching with the heel cam).

The repair took about 10-15 minutes on the trail, including the time that it took to retrieve the remnants of the cable that flew off at speed down the hill, while silly me, was searching for it up the hill. The time also included a search in a pack by a kind skier to find her trusty Swiss Army Knife with which to cut the cord (Shame on me for my lack of preparation, but at least I had the cord!).

I completed the trip back to base and was unaware of the temporary binding providing any lesser control in my Tele turns from the right-hand side (the repaired side).

“An unkind person might suggest that my turns from the left-hand side are so awful that I could not tell any difference.” Anyway, here is a little video of my Telemarks. You can judge if I am being rough on my bindings and how bad my turns are.

The real test was that I enjoyed the run down the mountain, with fading light and many tight Telemark turns on the icy surface and I just forgot about the repair. When I released the binding at the snow line I was also pleased with how well the binding tension was maintained.

Also, a simple device to provide heel lifting stretch would be another improvement (described in part 3). While my post focuses on a temporary cable repair for a cable binding, it seems to me to be another effective way of fixing the broken duckbill problem described in the above-mentioned post.

Avoiding an abrupt tie-off at the back of the duckbill bracket (as in the photos above and below) may avoid the cord wearing at this point (against keen metal edges) as described in their post. Running the cord around the front of the binding might be a better option. It would provide a long bearing surface for the cord. As shown in the next photo, running the cord around the heel to make the cord longer to enable it to stretch more and make a tension adjuster seems like a good idea. My repair described in Part 3 uses what I think is an improvement on this idea.

Part 2. Better temporary repair kit- Will a bicycle spoke do the trick?

I was delighted with my field repairs for a day trip. However, I had installed my last replacement cable from home,…. there was no more….. my particular beloved binding (like me) is so ancient that it appears to be no longer listed.

Consequently, I was keen to come up with a field repair that would be both quick and a more substantial repair option for ski trips that can last for a week. Ideally, it would engage with both the stretching/adjusting springs to provide full spring stretch and cable length adjustment of the original cable.

It is time for an ode about the relationship between necessity and invention in that popular saying:

What relationship have necessity and invention with each other?
Most unlikely to be siblings, sister and brother?
A causal relationship for one is likely true,
Search for that familiar word, I don’t have a clue,
Oh, I found it, I must be necessity’s father, or is it mother?

The key to such a repair is finding a strong fitting (preferably from rubbish, that’s trash for those over the big ditch) that can feed along inside the small diameter (~3.6mm) of the spring assembly. It then needs to be locked into place with the small slotted disk (or similar), as used on the original cable ends. The fitting also needs a suitable anchor point at the other end that can be connected to a cord or cable. Such an anchor point will clearly not be able to fit through the narrow springs during field repairs. It also should have broad soft edges where it connects to the cord and preferably accommodates multiple widths of the cord.

I had some high-tensile bicycle spokes that fitted through the springs and the threaded end device could then be replaced to become the retainer for the slotted disk.

I made a couple of prototype repair connectors with spokes. However, as soon as they were made, I could see that they could be much better and more appropriate for field repairs on-the-run in the snow with gloves and cold fingers.

It might even become a way of keeping my beloved but discontinued Reva Rottafella bindings going forever?

Before we leave the Riva Rottefella repair solution I should mention that the cable nuts are difficult to undo with out a suitable tool. So here is my little bush trick to get them undone if like me you forgot to pack your multitool.

Part 3. A universal binding cable repair?

Given my bad track record of wearing out bindings, I thought it would be good to make a simple repair kit that would work with:

• Any simple 75mm duckbill and cable type Telemark binding,
• A broken duckbill on a three-pin binding,
• Or even my 7tm bindings that do not even use a cable (They have a polymer strap below the boot that serves this holding function). If the strap pin broke, it would be nearly impossible to repair without a workshop.

While evaluating the previous repair method, using 3.5mm dia cord, I could see that the repair could be much stronger and less prone to cord damage if the cord was much harder and less stretchy polypropylene polymer and a much fatter. I found that a 6.5mm cord could just squeeze through the holes in the binding if the ends were melted, stiffened, thinned and shaped with a long taper. So the universal binding repair would be made with this cord (It would be equally applicable to the previous method).

A universal binding repair should ideally have a stretch/spring function inbuilt to allow for heel lifting when it bypasses the original springs. By my assessment, any stretching component would be best located at the heel. This would mean that it can serve both sides. It will also minimise the longitudinal movement of the cord that could cause abrasion damage to it. The design should also make it easy to quickly put the binding on and off. “Ohhhh…..and ideally should cost almost nothing and be made with rubbish. I think the following design ticks all boxes.”

The sliced/loop of a motorbike’s inner tube is the start and finish of the loop of the universal binding cable repair kit. The interlocking loop of the cord shown below was first sewn through and bound or whipped tightly in three places with strong polyester/cotton sewing thread.

Then the union was impregnated with diluted RTV silicone rubber before being whipped, once more all over, with a strong nylon cord that was also impregnated and glued*. A final whipping coating made from a stretched ribbon of pantyhose fabric and silicone rubber made a smooth finish to the union (see later photos).

Note* The RTV silicone rubber does not bond strongly with polypropylene. However, it keys into it to give grip and the impregnation repels water. The remaining whipping fabrics glue very well and their compression forces hold the polypropylene union tightly together. Details of the impregnation and glueing with RTV silicone rubber are described in another post.

The slice of the inner tube was flattened and wrapped in four folded laminates of simple ‘shirt cotton’ that were impregnated and bonded with silicone rubber. Hand stitching was used to hold the laminates together while the silicone was curing.

A lifting handle was attached at the top of the heel assembly with a glued rolled seam. This was added to make it easy to lift the tight heel assembly into place when standing in the bindings. “I found that, as luck would have it, it also can help to pull (or peel) the heel assembly off if the heel of the boot is lifted up from the ski.

I also envisaged that the handle could also be used to hold the assembly up in place if the heel shape of the boot would otherwise allow it to slowly slip down. This holding force could be provided by tieing a light cord to the handle and then tieing it around the boot ankle.

To demonstrate the potential universality of the binding repair kit, I used it to simulate its use with 7tm bindings that don’t have a cable but have a polymer strap below the boot instead. I have pretended that the main anchor has broken. This breakage happened to a friend’s skis while we were skiing in Japan and he was very lucky to find a kind technician who found a spare part and spent considerable time replacing the part.

Protective sleeves for binding cords and cables.

Previously, I assumed that my cable breaks have been due to unavoidable corrosion inside the protective plastic cover on the cable. However, closer examination of a much-used cable indicates that abrasion wear was probably the major contributing factor to the break.

A short sacrificial piece of tubing could be slipped over the cable or cord to provide abrasion protection. The tube could for example be a piece of plastic airline or laboratory tubing.

Lastly, in a rather circuitous way, it became obvious to me that fitting protective tubes to the original cables may prevent the damage that contributed to their demise in the first place. The tubes on a cable binding might not stay in the correct place, so I thought that some of my stiff rubber 12mm diameter glow-in-the-dark fishing beads might make good stops for the tubing. I normally use these beads as cord locks for the fine draw cords on my backpacking gear bags. In that case, I burn a smaller hole through the bead that has been cut in half through the original hole that is normally too big.

For the tube stop, I used a whole bead and enlarged the original hole with a heated piece of fencing wire. In this way, the cable could be tightly threaded onto the cable, using a drop of dishwashing detergent as a temporary lubricant.

Discussion & conclusion

A strong synthetic cord can be used to provide a substitute for a broken binding cable. For in-the-snow repairs, it would be best to cut the cord and melt the ends to make the threading easy. Marking the cord at the critical points along its length, for example, the hitch knot, would make the fitting much quicker. Pr-tieing the hitch knot in advance would be even better.

I think the ultimate, quickest and most convenient solution is the cord with a heel piece made from a slice of an inner tube and a tensioning loop tied in it. The rubber band can maintain steady binding tension during heel lifting and lowering. It can be fitted and unfitted with most of the convenience of normal cam action binding. A simple slice of the inner tube without the cotton cover could suffice, but it would not be as easy as the fully formed heel assembly for getting in and out of the binding. In any case, such a slice of rubber, even an extra one, would be a prudent addition to any repair kit.

The simple universal binding with the rubber heel assembly can be made to fit almost any 75mm duckbill type binding (your own bindings or a ski friends). If prepared at home it could be easily fitted and adjusted on-the-snow in less than 10 minutes.

[Add a photo of the repair kit with a spare rubber in a plastic bag]

Lastly, 3.5mm diameter cord will work, but 6.5mm cord can be used (it is a tight squeeze ) and if made of polypropylene it will have minimal stretch and should better survive abrasion and last longer. Suitable tubular cord covers should be able to totally prevent abrasion on cords and cables.

Addendum 1- First field test of the universal binding cable repair kit

I have just returned from a week-long backcountry ski trip where a friend broke their Targa G3 binding on the evening of the first day out. The cable broke where it feeds into the tube that wraps around the heal and no practical repair could be made.

My cable repair kit with the silicone cotton lifting handle was pressed into service and demonstrates that as expected it could work well with this third type of binding.

The cable repair kit functioned without fault for the rest of the week’s skiing and for the trip home. It required no further adjustment for the week of skiing.

It was easy to fit and also was as easy if not easier to engage the heal tensioner than the original cam tensioner. The handle could also be used to disengage the tensioner, as shown in this video.

My ski friend assured me that the repaired binding functioned just as well as the original one. I was carrying the makings of another 2-3 binding repair kits without the easy engagement handles and told my friend that if I broke a cable I would take back the one with the handle and he would have to make do with another repair kit without the handle. Luckily, this situation did not arise, but I did help with the repair of a broken ski stock with my trusty repair kit.

Tim