Wednesday, December 29, 2010

Why No Isotropic Structures?

I am occasionally asked why ski bases don't have random or non-directional structures.    Typically the question is posed with the addition of "...like a golf ball!"


The idea of random isotropic surface structures seems attractive at first.    Something simple, elegant, and maybe even something easy to apply to a ski.     Imagine a surface finish on a ski that could be sprayed on! Perhaps smooth indentations on the ski base from a shot-peen gun, or cuts from an abrasive sandblasting apparatus.    That seems simple and relatively inexpensive.    But would it work?

Golf balls travel through the air, spinning, without a set orientation to the travel direction (imagine having to line up the golf ball just so on the tee...!).     Additionally, the axis of spin can translate while the ball is flying through the air.      So a non-directional isotropic arrangement of the dimples is best.  

Angled pattern, but the structure elements are
all aligned length-wise.
But a ski doesn't travel randomly; it doesn't behave the same in all directions.    Cross country skis travel in a straight line, and always work through the snow tip-to-tail.     For this reason, the base structures are optimized to maximize the benefits, and minimize any negatives.      Structures and base finishes need to take into account the motion of the ski against the frictional interface.

Note that while skating there is typically a bit of torsional force and movement of the ski in the snow.   Additionally, skate skis usually slide through less transformed snow than a ski in a set (classic) track.    So skate skis and classic skis are sometimes treated differently.

The skate ski structures are tending toward broken patterns, which have easier separation and less stickiness in the ski release.      Long, straight, continuous linear structures with continuous frets tend to track well but have a stickier release or separation from the snow.        Broken structures with linear elements, but with angled interference patterns are proving to work very well on both skate and classic skis.

So, skis don't get the simple isotropic base structures, but rely on lengthwise oriented patterns.    The ski structure designs utilize depth, spacing, orientation, and pattern to optimize the ski speed through the snow in various conditions.

Monday, December 27, 2010

Maine, mainly

The Technolami Mantec Ski Numericontrol 140 NC
Sixty five pairs of skis showed up, in big clumps, during the 4 days before Christmas.    Primarily they were skis needing last minute grinds before US Nationals in Rumford.        It resulted in a week of long days, but all the skis were completed on time, and are on their way.        I have a hunch that some of those skis will be on the podium next week.       Good luck to all the skiers heading to Rumford!

January Stone Grinding Schedule


Your big ski events are coming up in the coming weeks, so make sure your skis are as ready as you are.

Prepare all of your skis to run their best with a fresh grind and hotbox service. At Nordic Ultratune, a grind batch starts every Thursday and those skis are ready for shipping on the following Monday -- just 4 days later.

Return shipping is FedEx Express Saver, which is 3rd day delivery. So, skis that are shipped out on Monday will arrive back to you on Thursday.

Here's the upcoming service schedule at Nordic Ultratune. Use these dates to make sure you get your skis ready before your most important races.
  • Skis in by Dec 30th will ship out on Jan 3rd and arrive back to you by Jan 6th.
  • Skis in by Jan 6th will ship out on Jan 10th and arrive by the 13th.
  • Skis in by Jan 13th will ship out on Jan 17th and arrive by Jan 20th.
  • Skis in by Jan 20th will ship out on Jan 24th and arrive by Jan 27.
  • Skis in by Jan 27th will ship out on Jan 31st and arrive by the Feb 3rd.
There is still plenty of time to get a fast grind on your skis before the season's big marathon races kick off!     But don't delay... ...fast boards are a joy to ski on, and they're a real advantage.

Saturday, December 25, 2010

Merry Christmas

Christmas day here in Mazama has been a nice day off.     Today is the first day off that Margaret and I have had together since September!  
At the Basecamp Bridge over the Methow River
After an early breakfast, we skied from the back door, heading up-valley at a relaxed pace.   Stopping for photos and chatting, but wary of tree-bombs from the heavily laden pines and cottonwoods along the trail; the trees are dropping snow and branches today.

Margaret stole my "Lake Express" hat.   It definitely fits her better than me.
The Methow River is just a trickle at this time of year, and sometimes there is no surface water at all.    This year there is noticeable flow; it makes a pretty backdrop with the snow.     The ski trails pass by the North Cascades Basecamp, which was taken over by Steve and Kim Bondi this past autumn - they're doing a great job there.    From the Basecamp, the trail crosses the river, and offers long kilometers of trails in the narrow valley near the confluence of the Lost River and the Methow.
Skis leaning against the side of the house.
We skied for 2 hours and looped back to the house.   Back at home this afternoon, there's time to relax and get started on a book.    Some phone calls with family and friends.      There's not as much to do when you live in a quiet, snowy, rural mountain area, but it takes longer to get anything done.   So it works out well.

I hope you all are having a peaceful day and are finding comfort and joy with family and friends.

Saturday, December 18, 2010

From the house with the spouse

Skiing with Margaret
We've got a ton of great snow here in Mazama, WA right now.    About 3 feet of snow in our yard.

It's a Saturday morning, and for me that means a chance to get up early and ski right out the back door with my wife Margaret.     We get up early and out the door at the first light since my ski hours are constrained by my work schedule.    For Margaret it's a normal weekend - and she'll often ski with me, then sneak out later for another ski later in the day.

Of course, I've got to get to the shop by 10 to get things rolling.    Nordic Ultratune is really hopping right now, right in the final days before Christmas.   If you're in town, stop in at Nordic Ultratune and say Hello!

Rode Super Extra Blue
The classic skiing has been especially good in the past week.    I've been skiing on the same Rode Extra Special Blue for several days, just a little touch up before going out each day.    While the weather holds in this pattern, I'll stick with it.

If you need any Rode grip waxes, just let me know.   Nordic Ultratune has all the Rode stick waxes and klisters in stock.     Rode grip waxes are very versatile, and should be part of your wax box.

Monday, December 13, 2010

Moving Snow

22 inches of new snow fell on Saturday night here in the upper Methow Valley.

I spent most of Sunday morning moving snow so that I could get to the shop, where I got the opportunity to shovel a couple feet off of the sidewalk and entryway to the building.

Moving two feet of new snow.
Needless to say, I didn't get any skiing done on Sunday.    But all the outbound skis were ready for FedEx, and the Nordic Ultratune stone grinding schedule wasn't affected by the big winter storm.

The local trails association is hustling to get all the trails packed down and beautiful, and I'm hoping to get a really great long ski outing on my day off this week.

Stone Grinding Schedule

Here's the upcoming service schedule at Nordic Ultratune. Use these dates to make sure you get your skis ready before your most important events.
  • Skis in by Dec 16th will ship out on Dec 20th and arrive by the 23rd.
  • Skis in by Dec 23rd will ship out on Dec 27th and arrive by Dec 30th.
  • Skis in by Dec 30th will ship out on Jan 3rd and arrive by Jan 6th.
You can see that there are still a few service batches scheduled before Christmas and the post-holiday races (including Sr Nationals!).     There is still time to get a fast grind on your skis before your biggest events! But don't delay... ...fast boards are a joy to ski on, and they're a real advantage.