questions on ski choice and ski length

Question
QUESTION: Hi Glen,

I had a couple questions if you could please,

I was interested in buying either the Fischer RX8 or the FIscher Race SC ski from 2006 or 2007.(Please note this is not the the world cup version, but the model between the world cup and RX8.

If your familiar with them, can you give me the real difference between those skis?  Ive tried the rx8 which I really liked, but then someone suggested I would be better on the race sc.  Im worried that the race SC might be stiffer and too aggressive than the RX8.

Lastly Im having a tough time deciding on ski length.  I have demoed the rx8 only in a 175.  There are no Race sc models in my area to try.  

Im thinking of either the 160 centimeter or 165 centimeter.  I currently ski the K2 mach S from 2001. its 157 centimeter length, 12 meter turn radius, 110-63-94.  The only real time I found the K2 too short was on a steep pitch on soft spring snow.  I
actually bit it falling forward.  never happened before.  


I should give you some details on my abilities perhaps as well.  I just entered the advanced ski levels as last year I was able to consistantly carve short slalom turns on blue, green and easy black runs minus the softer snow or solid ice of course.  


my goals this year are two increase my slalom skills mostly in varried conditions with the ocasional recreational gs turn.  


Any help you could provide would be wonderful.  Thanks so much!

Toby

ANSWER: Can you let me know how much you weigh and how tall are you? The relative difference in lengths will be a factor of your mass and the leverage that you can bring to bear on the tip of the ski at the start of the turn.

---------- FOLLOW-UP ----------

QUESTION: I apologize as I forogt to give that information initially.  

I am 40 years old, 5'7" tall, approx 175lbs.

Thanks very much for your help!  

Answer
Thanks for the information. Regardless of which ski that you chose I believe that you will have more overall success with the 165 length because this offers both more stability at higher speeds and more flotation in deeper or softer snow. Your weight is certainly enough for this length in either of these two models. Now as to the relative difference between the two skis though I am not intimately familiar with the Fischer line the manufacturer's information on the two skis provides the clues that make it possible to make a relatively informed suggestion. First off the dimensions of the ski are identical as is most of the construction. This is a very common manufacturing practice to simplify costs and align skiing characteristics between the soft slalom ski in the line (RC4 RACE SC:For dynamic specialists. The slalom carver with somewhat softer flex. Smooth and agile, with Air Carbon and World Cup Tuning.) and the high performance though recreationally based carver (RX 8 FIRE FTI: The sidecut and waist of the ski allow the tightest and most nimble turns. Great for aggressive skiers looking for performance and fun). Both have the same geometry (shape)and produce the same basic radius through this pattern.
RADIUS 13 m / 165 cm
SIDECUT 116 - 65 - 98
LENGTHS 175, 170, 165, 160, 155
One of the major differences is the World Cup Tuning on the RC4 RACE SC. This will be to allow for superior gliding characteristics in average snow conditions and superior edge grip on hard snow.

So what are the differences in ski performance? My own experience has been that the race ski will be more capable of creating moments of acceleration in the turn. In other words a capability to add speed if the skiers technique allows it. This is a process of actually using the forces stored in the ski during a turn as a result of the ski  bending and then returning to its original shape to help push the skiers mass inside the arc in the straightest path possible or to rebound the skis into a new path faster. It will rarely occur unless technique is in tune with the equipment. So its really not a handicap to a less technical skier but allows the opportunity to experience this if timing and circumstances are right. It also requires a very specific set of conditions underfoot(hard snow and speed). However the other ski will not react the same way on hard snow. My suggestion is to go for the race ski.

As well just a word of caution. Modern skis with 13m radii can be very nervous at higher speeds. Though they make riding a longer arc, and most people when they ski a recreational GS line as you call it are running somewhere between 17 and 19 meters, feel effortless there is a danger. This is because the tip, if it is suddenly loaded, will decrease or tighten the radius of the turn the ski was on significantly and suddenly with often fairly dramatic results. If you are going to ski at speed on slalom skis or even short carvers give yourself a space between you and any obstacles on either side of the turn of at least the width of the turn itself. In racing terms this is called the spill zone. When you go down or out at speed its not a quick stop and the distance to the trees on the side of the run gets eaten up pretty quickly in a fall. Unfortunately I am shocked at the many people I  know who have suffered injury and in one case even paralysis as a result of spinning out of control suddenly. They were literally carried into the obstacles by their skis. Though this can also happen in a race we have fences and crash protection systems in place to reduce the chance of injury.The major part of the skier population at risk  are the advanced recreational skier out on the mountain for fun.