- tip-waist-tail: 90-91-90 mm
- length: 173cm
- sidecut: inside edge - 4mm standard, outside edge - 4mm reverse
- tail-tip type: twin-tip
Materials (top-to-bottom) clear P-tex topsheet, flannel with
hand-painted graphics, triaxial
fiber glass (22 oz.), core (birch and poplar) and UHMWPE tip and tail spacers, triaxial
braided fiberglass (2-layers), clear base material and
- epoxy: QCM; resin: EMV-0049; hardener: ECA - 315 (15 minute set); 5
to 1 mixing ratio
- pressing time: ~11 hours
- weight: n/a
- inserts: steel 1/4-20 thread inserts configured in G3-binding
- date manufactured: July 28, 2005
Ski Builders: Kam K. Leang and Kam S. Leang
written by Big Kam (Kam K. Leang)
Why Kanana? Because it reminds us of a banana -- the shape, that
is. As with every ski, there's a story. If you're impatient and want to know
why without having to read on, the skis got their shape by accident. Yes,
by accident. And there's nothing wrong with accidents, you know. The transistor was invented by accident.
Sticky Notes by 3M were also by accident. An apple fell on Newton's head,
by accident... Anyway, the shape naturally conjured up the thought
of a 'banana',...so we have Kanana. Originally though, I wanted to build a ski with no shape,
just zero sidecut. But to our surprise the base material warped after we cut
it. Instead of throwing out yet another pair of good base material,
Little Kam and I decided to just lay them up.
Coincidently, other SkiBuilders were also experiencing the warping base behavior
at the same time that Little Kam and I noticed the phenomenon. The topic
is discussed in the forum (click here to join the discussion).
The cause of the warping behavior isn't clear yet, or at least it's not clear
to me. We speculate that we got a bad batch of p-tex. If anybody
knows more, please share.
Over the month of July I went down to So. Cal. to visit my family. I
spent some time with Little Kam. Every time my cousin and I are together,
we talk about skiing or building skis. At first we
got our skiing fix by going to San Gorgonio Mountain and Jepson Peak (see the trip
report that Little Kam wrote). Then to satisfy our ski building
appetite, we built the Kananas in Little Kam's shop in Riverside, CA.
The motivation was I
wanted to try out his new press and share some ideas with him about design. Kam
has been busy making skis and he had a couple new techniques up his sleeves that
I wanted to investigate.
So at first I designed a zero sidecut ski that was approximately 125mm
underfoot. The skis were 178cm in length. We drew up the design, then
cut out the paper template. Before cutting out the base material, Kam and I
glued up the cores. I decided on a mix of birch and poplar.
My goal was to build a more backcountry friendly ski, i.e., something
that was reasonably lightweight, and perhaps narrow. Poplar is nice and light.
After the glue dried, we attached UHMWPE material to create sidewalls. Then
we profiled the core using Little Kam's planer. For the first time I saw Kam's new profile jig for
profiling with the planer.
This technique is described on this site. Kam's method is different than the way Kelvin and I profile our cores --
a router. Anyway, after we profiled the core, the next steps were to cut the
base material, bend the edges, make the graphics, and finally press.
Our progress came to a hault after cutting out the base material and gluing on the edges.
At this point we noticed
something strange. The shape of the bases were warped, including the edges.
Strange. At first we thought it was the template shifting during the
cutting process. So we cut out another pair of bases and glued edges to
them. And again the bases were warped. The bases warped from zero sidecut
to a design with sidecut on one side and inverse sidecut on the other.
It looked like a banana, hence the name Kanana. The warping was rather significant. We
measured up to 10mm of deformation over the 178cm length! Puzzled by the
behavior, we started to investigate the cause.
We did not find any evidence that the warping was dependent upon the method
used to cut the base material. For instance, using scissors, utility knife or router
didn't make a difference. One interesting observation was the warping
occurred within minutes after we cut the base material. This observation lead us to think that perhaps there were internal
stresses that, after we cut, caused the material to take on another -- more
stable -- shape.
The other cause could be related to temperature. It was rather hot in So.
Cal. in July. But temperature being the cause didn't seem to make sense
considering there wasn't much of a gradient. Kelvin found information that
claimed the p-tex had a very high coefficient of thermal expansion. That
could explain it, but during the time of warping, there wasn't much of a
temperature gradient. The garage temperature more or less
remained constant, ~90 degrees.
At the same time that Little Kam and I discovered the warping, a post
appeared on SkiBuilders' forum discussing the same subject (click
to see the forum).
What a coincident! Surprised, I we continued to investigate.
Interestingly enough, they were also working in a hot environment. We didn't
really come to a definite conclusion about the cause of the warping though. Maybe
they got a hold of a bad batch of p-tex too. Hmph.
Little Kam purchased his p-tex from Durasurf. I called Durasurf and
spoke with someone who I thought was an engineer. He pretty much told me
that it could have been a bad batch. Furthemore, he told me that the
effect, also known as "cambering", was rare, but it occasionally pops up and is usually associated
with a mistake in the manufacturing process. Whether I believe that or
not, there wasn't much I could do.
So I decided to lay up the warped base material. Being that homemade
skis is an experimental process (and of course we're trying to have fun), we
welcomed the Kananas as an addition to
our quiver of prototypes. It's definitely an odd design, where one side
has sidecut and the other has inverse sidecut.
Anyway, below is a close up
of one ski, showing the
inserts and the sidewall. For durability, the inside edge sports a UHMWPE
sidewall. The outside edge has birch sidewalls.
The graphics were simple. We used cloth and painted over it with cloth
paint - nothing fancy. The QCM epoxy was new to us. We used the
fast 15-minute setting version, and it was fast! If you decide on this
type, then work fast. We laid up one ski at a time and when working in a
garage where the temperature was >80 degrees, there was little time to spare before the
epoxy set. We managed, but a bit slower setting time would be nice.
Overall, the Kananas turned out pretty nice. The final design has a
narrow shape, roughly 91mm underfoot. The original design was 125mm, but that would have
been a bit much for a backcountry ski, especially on steeper terrain. I toned it down quite a bit, and
I'm satisfied with the profile 90-91-90mm.
Test Reports (by Kam K. Leang)
July 30, 2005, Columbia Glacier
Soon after the Kananas came out of the press (cure time: 2-days), I took them back up to Seattle for
a test drive. The day after I arrived in Seattle, my friends Chris Cass and Skip
Swenson and I went to look for some skiing in the Monte Cristo area. If
you're not familiar with this place,
I've written a
few words about it here.
Instead of coming at it from the north, we decided to approach from the
south. Our goal was to find snow on the Columbia Glacier, just below
Columbia Peak, a neighbor of Monte Cristo Peak. Our thought was the
approach from the south would be fun, requiring some additional gear, e.g.,
We split the weight of the raft by carrying different pieces. In the
end it was worth the hassle because to get at the glacier, it was much easier to
paddle across the 3/4-mile lake instead of trying to find a way around the edge
of the lake, which was pretty much steep and overgrown terrain.
After hours spent on the approach, we finally stepped on the glacier.
There wasn't much left, mostly neve and water channeling through runnels.
I'd never seen so many runnels. There were rocks everywhere, but that didn't seem to deter us.
(Keep in mind that we're not typical skiers...at best, think of us as Patch
Skiers.) We managed
to find some skiing, and below is a photo that Skip shot of me making turns for
the first time on the Kananas. They were pretty fun to ski... think of
something with a split personality!
I enjoyed them very much, and they seemed to handle pretty well. I was
surprised to find how predictable they were. At first I was expecting them
to take me for a ride because of hybrid sidecut design, but they remained in
control. I liked feeling the regular sidecut on the inside edge -- felt
comfortable on harder snow. The
inverse sidecut on the outside edge was noticable -- they turned at the
slightest pressure. The narrow design was nice, too, especially on
harder conditions. Again, the snow was far from perfect. We found a
nice section of corn, but everything else on the glacier was pretty much like
Skip demonstrates the mandatory technique of a jump turn that
patch-skiers utilize frequently.
We skied to where the snow stopped....literally!
August 02, 2005, Paradise Glacier, Mt. Rainier
A few days after the Columbia Glacier adventure, I got a hold of Greg Louie
and we went to look for some skiing around the Paradise Glacier, on Mount
Rainier. The first thing we found was this neat little patch that Greg had
his way with...
After that, we got a little more serious and found some decent skiing near
the lower Paradise Glacier. We yo-yo'ed a bit and I got to test again
the Kananas. And they were great! I pushed them a little harder and was
surprised to find that they carved nicely. The one thing I noticed about
them was they required me to stay well balanced. I think the reverse sidecut
demands a little more attention than traditional sidecut skis, which
isn't a surprise, especially on harder snow. Anyway, here are a couple
more photos: first one is of Greg with Mt. Rainier in the background and the
second one is of me carving on the Kananas (photo by Greg, of course).
Greg getting busy. Mt. Rainier in the background. Not
bad for August.
Me on the Kananas.
Is there a future for this design? Of course. There's a future
for all sorts of other designs too. Variety is the spice of life....