Monday 30 March 2015

Dynamic Transition

Onemississippi.  If the time to say that is the length of time it takes to make a short radius turn, then the dynamic transition between turns is about half way through the one part of onemississippi.   That's sliding a 20-30 lb weight (skis, boots and feet) 4 feet sideways in 0.1-0.15 second, about 50 to 40 km/ hour.  Fast.  
I mentioned before that there are 4 ways to make the transition. One is to start the transition by a quick turn of the hip, another is to knock the previous dominant ski knee against the other, and the last two are similar.  The third then is moving the previous dominant knee quickly toward the other. The last is moving the previous dominant knee towards the other and then pressing on the big toe, steering the ski.  They all have one thing in common in that the inside edge of the previous dominant ski is engaged for a fraction of a second flipping both skis from one side to the other.  
My preference, the last, is steering the ski.
   When I start the transition, say, turning to the right, my right foot drops back slightly so I can press on my big toe (pad). At the same time, I tilt my right knee in and press on my big toe, thus engaging the front edge of the ski. The left ski is released and mimics the motion of the right ski. For an instant, both skis can be disengaged and then, the front of the left ski engages, followed by the right.  I control how and when the left foot engages. Almost like hopping from one foot to the other.  After some practice, it becomes automatic.  I spent about a season before I was comfortable with the process.
One of the characteristics of the dynamic transition is that your leg relaxation time is less and so, using it continuously can be tiring if you are not in shape.  This is caused by being in full control of the turn, right from the top of phase 2 to the end of phase 3. For racing that may last only a few minutes; an athlete wouldn't notice.   When toppling through the transition, you get a bit of a break and start your turn later with a foreshortened phase 2, the other extreme. 
Steering the ski has an advantage. You can control the length of the transition by controlling the amount of steering.  This gives you more control for adapting to changing terrain.
Your body is always facing in the general direction of travel.  
The first few times, it feels as though you are tripping yourself with the skis crossing beneath you. The initial engagement of the right ski is enough to make the transition and so you  can choose to lift both skis off the ground if you wish.  Playing around with this is fun  and adds a new dimension to recreational skiing.
 My ski lessons, and previous blogs are prerequisites for the dynamic transition and the "raison d'etre" .  My words of wisdom are to start slow and get the movement right before turning on the speed.

Monday 23 March 2015

Flat Boot Fitting

When standing on your skis, on the snow, with your feet about a boot width apart, the skis should lay flat.  If they don't, you may have problems making your turns and gripping the snow with your edges.   Some boots like mine have a side cant adjustment (bottom picture left side) but for me, I need a lot more.
I have a problem being bowlegged and so, to flatten my boots, I have to add shims to my boot insert.  My shims are about 3/8" thick and made of rubber (1/4") and a couple of pieces of heavy felt. You can make them with just rubber.  I fasten them in place with duct tape and then push the insert carefully into the boot shell.  
Then I relocate the buckle catch on the top boot buckle to make room for the shims in the shell. Bottom picture.
The shims on my boots are located on the left side of the right boot insert and on the right side of the left boot insert.  
This is an easy, inexpensive, and very effective way to adjust your boots' soles to lay flat.
To check your boots, put them on and snug them up. Then stand on a hard flat floor.  
Start with you boots touching. With your one foot flat, only the outside edge of the other boot should touch the floor.
If not, you are knock-kneed and need shims on the outside side of your inserts. 
Or continue.
As you separate your feet about an inch at a time, you should reach a point where both boots sit flat on the floor, about a boot width apart.  This should be your normal stance on skis.  
If not, keep widening your stance until both feet are flat on the floor.  You  are probably bowlegged and need shims like mine, on your inserts at the insides of your legs.  
The best way to make a shim it to use rubber from an old tire inner tube (Tire Shop?).  Cut a number of squares to make layers. Then, by trial and error, add layers until your boots are flat at your normal stance.  Try stuffing the rubber shims in place before fixing them with duct tape. 
I know there are some companies that will mill a bevel on the bottom of your boots but this is expensive and you only get one chance to get it right.  A ski shop where you buy your boots should be able to help if you show up with all the parts.  
List: scissors, inner tube squares and the rest of the tube, contact cement, duct tape.  

Monday 16 March 2015

A New Beginning and About Physics and Skiing

Three years ago I had another new beginning.  For me it changed the way I ski and explained most of the mysteries that I have puzzled me for years.  This new beginning helped me put together all the various pieces that I have accumulated into an integrated package that makes good sense to me. 
The final piece was to change the transition phase between the end the arc of one turn to the beginning of the  next.   Instead of toppling (leaning into the next turn) from one turn to the next, I learned how to steer between turns.  This enabled me to gain control not near the middle of the turn but at the very start of the turn, the next arc.  I spent the following ski season, playing with various parameters that affected the outcome.  I found four different ways to affect the transition but in the end found that steering the skis through the transition is the best.  During this time I tried to define what skills are needed to perform the transition.
What I found was that we need a new way to teach beginners how to ski.  We need to concentrate on the basic skills.  I found that it is really hard to initiate a new beginner course into an old traditional system.  Hence my free manual in previous posts. In the manual lessons, I stress what I believe are the basic moves in skiing.  
I call this move the Dynamic Transition Phase.  Besides the basics for intermediates, I suggest learning how to side slip on groomed runs,  braquage (  
and side slipping on moguls. Notice the upper body in the video is always facing down hill in the general direction of travel.  Besides side slipping, this is a good demo of counter rotation or pivoting.  For a more complete description of the Dynamic Transition Phase, I have included another download of my notes,  About Physics and Skiing . See The Turn, Phase 1 on pages 3-5.