chevron structures

Where's the science behind chevron structures ?

A "diagonal" structure has certainly an effect to create water
droplets and broke them into smaller droplets to glide onto.
But I don't imagine a ski acting like a wheel and evacuating water all
base long. Evacuating water is perhaps not desirable at all..

What about the new Swix T405 rolling (expensive) tool ? does it
produce real "diagonal" structure/imprint or are they common straight
lines with a back offset, giving a diagonal look.

On Mar 18, 12:09*pm, wrote:
Where's the science behind chevron structures ?
A "diagonal" *structure has certainly an effect to create water
droplets and broke them into smaller droplets to glide onto.

I do not know what the science is, but my understanding of heavy
structures like these are to reduce the "suction" or "adhesion" the
ski shows when you are in warm, wet snow. My descriptors of "suction"
and "adhesion" probably are not technically correct, but I think folks
know what I mean. My shop calls them "arrow" structures -

http://highpeakscyclery.com/page.cfm?pageID=199

What about the new Swix T405 rolling (expensive) tool ?

I've never seen this tool in the US, but it looks like the V2 Rilling
tool Jenex sells. Look at the structure here on p.12 -

http://jenex.com/cat2009binder1.pdf

You can see that it does press an actual arrow structure into the base
material, not just giving it that "look".

Does that help?

- Bob

On Mar 18, 12:09*pm, wrote:

What about the new Swix T405 rolling (expensive) tool ?

It just hit me that this tool is over US $ 1300!!!!!!!! (1027 Euro's)
No wonder I haven't seen one. It makes the rolling structure kit that
Boulder Nordic sells seem like a bargain at $ 500!

- Bob

On Mar 18, 10:22*pm, highpeaksnordic
wrote:
On Mar 18, 12:09*pm, wrote:

I do not know what the science is, but my understanding of heavy
structures like these are to reduce the "suction" or "adhesion" the
ski shows when you are in warm, wet snow. *My descriptors of "suction"
and "adhesion" probably are not technically correct, but I think folks
know what I mean. *My shop calls them "arrow" structures -

Suction, adhesion... This is well understood by anobody interested in
making his skis faster, I guess.

My question is why a "chevron" (as mentionned by Swix on the T405
information. Sorry if this is not the correct english term for it)
structure is better than the same structure, not chevron ?

And to push the question to a higher level : Why a nice looking,
perfectly regular structure would be better than a random structure ?
Snow crystals or water droplets are random, aren't they ?
So, interaction beetwen base and snow is random, anyway. This is
science or what ?

On Mar 18, 6:00*pm, wrote:
My question is why a "chevron"
structure is better than the same structure, not chevron ?

Maybe I'm missing something here, but the answer seems simple to me -
by virtue of its design, a roller or drum tool has to press "a nice
looking, perfectly regular structure" into the ski base.

This is science or what ?

It is rapidly becoming a science, just listen to the predictions about
how important structure will be at the Canmore Olympics. There are a
few "random" structures out there that seem to run pretty well in
widely varying conditions and some that work spectacularly well in a
very narrow range. Many people on this newsgroup hold Zach Caldwell
up as the Guru of Structure; having spent time with him, I think he's
got way too much common sense (along with a quick wit) for me to tag
him as a "scientist". He is a guy, though, who seems to have the best
handle on snow interaction with ski base material and tries anything
and everything to get a ski to go faster.

- Bob

highpeaksnordic wrote:
On Mar 18, 12:09 pm, wrote:

What about the new Swix T405 rolling (expensive) tool ?

It just hit me that this tool is over US $ 1300!!!!!!!! (1027 Euro's)
No wonder I haven't seen one. It makes the rolling structure kit that
Boulder Nordic sells seem like a bargain at $ 500!

Even more of a bargain:

The local ski shop near our mountain cabin (Solbu Sport) is run by a
retired couple, longtime skiers both of them.

During winter break I had a pair of Madshus dry snow classic skis in for
grinding: These skis had never been grinded, and they actually had a
very pronounced depression in the middle, i.e. the edges were raised
compared to the center.

Mr Solbu first ran them through his machine multiple times to make them
flat, then added the final structure.

Total cost: NOK 230 or less than $40.

I could do this a _lot_ of times before getting close to $1300, right?
:-)

Terje
PS. Former Olympic and World champion, father of Bente, and Norwegian
Fischer distributor Odd Martinsen supposedly has had his skis grinded by
Solbu. :-)
--
- Terje.Mathisen at tmsw.no
"almost all programming can be viewed as an exercise in caching"

*Many people on this newsgroup hold Zach Caldwell
up as the Guru of Structure; having spent time with him, I think he's
got way too much common sense (along with a quick wit) for me to tag
him as a "scientist". *He is a guy, though, who seems to have the best
handle on snow interaction with ski base material and tries anything
and everything to get a ski to go faster.


I think I read from him years ago something about chevron structures
being nice looking but no more efficient than the same structure, no
chevron.