Ski Flex?

Wow - that's a significant weight loss. It's a little hard to say what you
should expect at a lighter weight because closing flex is not a very good
predictor of performance for skate skis. Here's why: "closing flex" is
generally considered to be the load o the ski when there is 0.1mm of
residual camber left under the foot. It's a standard that was established
quite a while ago to allow for a layer or two of kick wax, and it is still
used for skate skis. Unlike classic skis, which tend to close fairly easily
at the end of the loading process, skate skis get quite stiff. I often look
at the "closing flex" of the ski, and also pay attention to how much
additional load is required to compress the ski that last 0.1 mm. So, my
numbers might read 76 + 12, which would mean that the ski closes to 0.1mm at
76 KG, and it takes an additional 12 KG to close the rest of the way. That
second number indicates how stiff or "hard" the ski is at closing. As you
can imagine, a 76 + 3 will ski very differently from a 76 + 15.

Your weight is now about about 69 KG. A 76 KG ski is about 110% of body
weight. For an Atomic that is stiff, but not out of the question. It really
depends on the pressure distribution on the ski at full body weight. The
2002 RS:10s tended to have a fairly soft forebody flex, so I would be
surprised of the ski plows really badly. I can imagine a scenario where you
might have a real "hot spot" in the mid-body of the ski, ahead of the foot.
If that is the case and the tip is fairly soft, the ski might be best suited
to sloppy soft conditions - especially slush. It is tempting to think of a
really stiff ski as a hard snow ski, but i hard snow the most important
thing is to have long edge pressure toward the tip and tail of the ski. A
ski with a soft tip and a "hot spot" won't be terribly stable on hard snow.

Then, of course, there's the scenario in which it turns out that the ski has
a harder tip than most and builds pressure evenly through the forebody of
the ski. In this case you might actually still have an all-around to
hard-snow ski.

And the ski might also simply be overfit and too stiff to be particularly
fast for you. I think my first scenario (soft snow) is probably the most
likely based on what I've seen. I think the last scenario(simply too stiff)
may be least likely. The best way to find out is to ski on them. But I
wouldn't recommend getting rid of them before the season starts if you liked
them last year.

I hope that helps. I suspect it might have just confused things a little
further...

Best of luck!
Zach


"Fitzgerald" wrote in message
news:wjM1b.235008$o%2.107375@sccrnsc02...
I've got a question for you Zach. I have a pair of 2002 Atomic Race Skate
skis,190cm.Flex #s on sticker were 76 and 2.3 When I bought them I weighed
180lbs. I skiied them all last year and loved them. Since October 2002 my
weight has dropped to 153. What can I expect when I get on snow this year?
Too stiff?
TIA
Fitzgerald
Derry,NH

Good to hear that the qualiy is fine. I hope they help. Remember, when
you're looking at the online pressure distribution curves at ernordic, that
those are generalized pictures of what a given model of ski might be like.
Skis actually vary quite a lot within a given model and flex. I think
everybody understands that the closing flex of a "medium" can be anywhere in
a large range. But equally importantly, the pressure distribution from one
pair to another can be significantly different. Those ernordic graphs do,
however, provide a very nice generalized brand vs brand description of
construction philosophy and performance.

Zach

"Bob" wrote in message
...
thanks Zach!
The quality is fine - I might be able to make some sense of those pressure
distribution graphs that some shop published... Does anyone have a link to
it? The store is in the midwest somewhere and the graphs show how the
pressure changes from unweighted to full weight in a nice 3-d chart for
each
ski.

TIA,
Bob

From: "Zachary Caldwell"
Newsgroups: rec.skiing.nordic
Date: Sat, 23 Aug 2003 09:18:39 -0700
Subject: Ski Flex?

OK - I've put those sheets on the website. This is probably a good
opportunity for another link:
http://www.engineeredtuning.net/

The PDF files may not be of fantastic quality, but they should get the
idea
across.

Zach


"kayakclc" wrote in message
om...
The ski flex question is an interesting one and any response pretty
much
has
to be limited. I do have some handouts with little pressure
distribution
graphics illustrating "overfit" and "underfit" skis. I made them for a
presentation at a coaches education program this spring. If you think
there's interest I could turn those sheets into PDFs and put them on
my
website...
Zach

Please do, I for 1 would be interested.

Thanks! Yep, qualiy is fine.

I liked the analogy of an underfit ski being like paddling a white
water kayak on flat water - since buying my skis 12 yrs ago I'm about
30 lbs heavier - hits the nail on the head. Up until last year I was
always packin' a kid so I never expected optimum performance from the
ski. Last year I spent 1/2 the time towing a kid and 1/2 in
freedom(don't get me wrong, I LOVE pulling the kids), that's when I
started paying more attention to the ski and started to remember how
it should perform. This year I want to get a new pair so I'm triing to
gain a knowledge base to make the right choice.

Thanks again!!