saw a good deal on leftover dynastar team course junior skis, wondering if that's an ok choice for western (sierra and rockies) conditions for an on-piste good junior skier.
post #1 of 9
10/3/07 at 9:44pm
the usual "skinny skis suck out west" reasoning may not apply to lighter weight kids.
|As kids grow, their skis scale up in the two dimensions relevant to surface area -- length x width. But the kids themselves, as three-dimensional beings, scale up in three dimensions -- length x width x height.
Let's define the Approximate Float Index, or AFI, measured in square centimeters supporting each pound of skier.
If you rejigger to isolate width or length, so you can hold the others contant:
(Note to math nazis: Yes, I know that pounds are English and cm/mm are metric. But it doesn't actually matter for these purposes and, as you see below, the math works out perfectly for my weight and skis, so that's how I'm doing it. Pfft!)
So here I am, Joe Schmo on the Bros -- 188cm x 11.3cm average (125-99-114) width / 212 lardass pounds = AFI of 10 square centimeters supporting each pound. Heck, even on 189 Pontoons, with a 13.7cm average (160-130-120) width, my AFI would be 12 cm^2 per pound.
Compare to a 90-pound kid on 153cm skis. To get the same AFI as me on my Bros, that kid needs a 59mm average width ski -- 90 lbs x 10 cm^2 per / 153cm = 5.88cm. To get the same AFI as me on the mythical 'Toons, that kid needs a 71mm average width ski -- 90 lbs x 12 cm^2 per / 153cm = 7.06cm.
Why did I choose 153? Simple -- that's the biggest size of the 103/65/91 K2 Apache Junior, which has an average width of 86mm, well above the 71mm average that a 90-pound kid would need to hit the same AFI as me on 'Toons. In fact, the 90-pound kid on 153 Apache Juniors would have a whopping 14.62 AFI -- 20% higher than me on 'Toons.
Yes, I know that other factors influence float, most notably sidecut. And fat skis are a lot of fun. But kids float pretty well on most skis. For me, on reflection, the wonderful thing about being on the Bros is that they restore the sense of fun I had as a kid -- eager to jump off groomers into anything deeper at the first chance. Maybe the AFI helps explain why.
But the upshot is, I wouldn't stress too much about finding the widest skis imaginable for your kid. He's going to float no matter what. My 70-pound daughter just switched to 136 Apache Juniors last weekend (16.7 AFI) and her skiing improved markedly, on groomed and ungroomed alike. Get him a quality pair of skis and he should enjoy them regardless.