A Binding Retrofit Gives
New Life to Old Technology
Photos, Story and Video
By Y.K. Idgadambr
How This All Started - This fall my twelve year old daughter said she’d
like to give telemarking a try. She’s been an alpine skier
since she was two and I guess she felt it was time to free her
heel. We bought a new pair of Garmont Teledactyls for her from
one of the Tt.com sponsors, and we already had a pair of Rossignol
skis in good condition ready to mount up, so the only question
left to answer was what kind of bindings to use. Relatively speaking,
the Teledactyl is fairly stiff for someone as light as my daughter.
She skis lift served slopes so skinning type motions were not
an issue. My main concern was helping her to make the alpine
to telemark transition as fun as possible. I had some old Riva
II’s in the shop but I was concerned that with her short
boot and the cable pivots on the toe piece that she’d pry
her sole right out of the toe box without flexing the boot.
A Little Bit of History - You’d had to have been in a pretty deep sleep
over the last several months to have missed all of the buzz created
by bindings with underfoot cable, strap or plate systems and
the control benefits they impart. Kudos to Mr. Rainey for bringing
a user friendly, high performance version to the market. Few
would argue that he is leading the race, with others in hot pursuit.
It is interesting to note that the idea of underfoot cable routing
has been around for awhile though, and no, I’m not thinking
about the Pit Bull series. The photo below shows a circa 1936
set-up. While it is a little hard to see, the cable through the
ski is a spring cable and there is a spring at the boot heel
also. Cable pivot point and retention all in one step. All you
have to do is drill a hole sideways through your skis. What,
the alpine guys are doing that now? (Does that mean they are
way advanced or just starting to catch up?) Good advice in the
note below the photo on that sock thing too!
Building the Concept - Anyway, back to those Rivas. A quick investigation
showed that even though the boots were short, there would be
enough cable between a new pivot point and the forward spring
ends to allow the cable to be re-routed. Instead of drilling
a hole through the ski(!), we thought it would make more sense
to drill a hole through a riser. A little bit of time on the
band saw and we had a riser that allowed a new pivot point and
also allowed some of the cable slack to be taken up in a stylish
way.
The areas along the riser bottom were cut
out so that the ski could flex more evenly without a big flat
spot where the riser was. On small skis this seemed like it might
be noticeable. It doesn’t show up well in this picture,
but there is a groove milled in the front end of the riser for
the cable to ride in. The cable is held in place by an orange
wire tie (color matched to her boots). The photo above shows
the pivot hole just behind the binding toe box.
The next step was to fabricate the pivot components,
which turned out to be the easiest part. The pivot assembly is
composed of the parts in the photos below; a through bolt and
self locking nut, and two cable guide clips. The clips are made
out of some UHMW polyethylene I had in the shop from before I
switched to using HDPE for risers. The holes where the cable
passes through are relieved on each end. The slots allow the
guides to be clipped onto the cable.
And Still More Modifications - You may have also noticed a non-stock toe bar. While
I was in the hot rod mode, I boxed the toe with some aluminum
stock because, well, I wanted to. The rivets were made out of
aluminum nails. The nail heads got reduced with a file while
I spun them in my drill press and then they were cut to the proper
length and peened in place.
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Normally I would have used t-nuts to mount
the binding to the riser, but in this case the binding is screwed
directly to the riser as this will afford more than sufficient
purchase to handle my daughter’s size and weight.
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Old and New Side by Side - With the pivot components installed in one riser
and the cables routed through the new cable clips the binding
now looked like this. |
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The binding toe in the rear of the photo has
the cables still in the old guide position. As noted before,
the groove in the front of the riser was milled just to take
up excess cable slack as they are standard cables with all of
the spacers installed. With shorter cables they could have run
around the front of the toe box in the normal fashion. The self
locking nut allows the bolt that retains the cable clips to be
left slightly loose so that the clips pivot freely.
Heel Risers Get Some Attention Too - The new riser for the toe meant a new heel riser
was also required. This all worked pretty well as I was able
to use most of the holes from where the alpine binding had been
mounted for both the heel and toe risers. The toe riser is constructed
from ¾” HDPE stock and the heel riser is 1”
HDPE stock. This difference in height gives her the amount of
positive delta or forward pitch that she felt was were she wanted
it. I also cut a relief in the back of the riser to lock the
springs and cable down when she is carrying the skis as shown
in the photo on the right, below.
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The hole in the heel riser was bored
to reduce weight.
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Finished! - With
all of the components assembled, the bindings looked like this
when set up for a size 24 boot on a pair of 150 cm skis.
How’d They Work? - Well, I was pretty sure that the modified binding
would help keep the ball of her foot down, but I was definitely
not prepared for what I saw when we compared the two set-ups.
The video below tells the story better than words ever could.
In both sequences my daughter is using the same forward pressure
to lift her heel and is applying the same downward force on her
toes. Note that the boot sole almost clears the top of the toe
box wing in the unmodified binding before the bellows is completely
closed and the binding is fully tensioned. In the modified Riva,
her heel does not come up as high because the bellows is completely
closed and the binding fully tensioned while the part of her
boot that is in front of the bellows is still largely on the
ski!
Link to movie
And on the snow you ask? First day out we took some runs on the groomers so
she could get a feel for the new world of the telemark turn.
I gave her perhaps two suggestions all day. The next time we
went skiing, she blew me into the weeds. Steep and bumpy black
diamonds she parallels and when the terrain gets smoother, she’s
laying down great T-turns and I’m having a hard time keeping
up ‘cause she is flying. I’m thinking that I’m
going to have to change those pivot points and find her some
old broken down leather boots if I want to keep up with her!
