Fischer's weird 5-point sidecut

[Johnny]

I was wondering what those strange sidecut numbers meant when I first bought two pairs of Fischer Explorer skis:

Sidecut: 60/50/59/50/55 mm

But I didn't bother. Until yesterday when I removed the bindings. Wow, that's an interesting shape isn't it? There is a bump in the kick zone... Then it narrows again and gets bigger near the tail...

I've seen 5-point sidecuts in powder skis tips but never before in the middle of a XC ski... (Well, I don't know a lot about XC skis...)

Not sure how this will translate on snow...?

[MikeK]

I was stumped for a minute but I think I've figured it out, at least in theory.

I think the idea is to make a double cambered ski turn by effectively making it into two single cambered skis.

So instead of flexing into one, smooth, continuous arc when edged, this should flex into two smaller arcs, each centered about each of the two waists. This effectively takes the double camber wax pocket out of the equation because it is now not the center of the arc, but the end of the two individual arcs.

It is similar to what I say I see when I flex a ski the Madshus Glittertind. Because of it's soft tips and tails, you almost wind up with two arcs with a flat, or maybe even concave center (being the wax pocket). This works if you are in deep enough snow that the ski can actually deflect enough to bend into this weird arc. They don't work well on hardpack because there is little sidecut and it takes a lot of force to remove that double camber and get the center of the ski to edge. As we know this ski is a huge compromise because it's narrow and doesn't float well in deep snow, which it almost needs to turn effectively, and had too much camber and not enough sidecut for hard snow, which it excels at for gliding.

I believe this Fischer is an attempt to make a ski with little sidecut and double camber work better on harder snow.

[Johnny]

Hummm.... If that was efficient, they would have used this in other XCD skis as well no?

A double camber ski is never really intended for "turning" purposes... I doubt you can turn this ski enough to really feel both arcs...

Actually, I think this one is a triple camber ski...
Man, it jumps! By itself!!!

[bgregoire]

Could they have tried to create more sidecut on a narrow ski for better turning while keeping it wider underfoot for better stability? I don't see the relation between the given specs and camber as Mikey suggests. What did you buy these for LJ, and do you even like them?

[MikeK]

Stiff double camber puts more pressure at the tips and tails. To me, it makes sense to try move the waists where the pressure is greater. Fischer called it S curve or something like that.

I think they also claimed it gave more width underfoot for climbing, but if they are really stiff DC, I wonder how much that really worked?

[Johnny]

I think they also claimed it gave more width underfoot for climbing

Oh, this might be it...! It totally makes sense...

I bought them for the bindings... I thought of putting the skis for sale but I'm not sure anymore... They're really fun... At least in the graveyard... ; )

Anyone interested in a pair of 184cm? Hey Mike, I could trade a few pairs of skis for your Annums...

[MikeK]

I'll trade you those mint 10th mountains you have... I'd also throw in a nice set of NNN-BC bindings...

I'm pretty sure that sidecut has something to do with turning. You guys may not see what I see, but think about flexing the ski from each of those narrower waists, and not the middle like you could with a conventional ski.

I'm also guessing it doesn't work all that well or causes some other weirdness because Fischer stopped doing it.

[MikeK]

Oh - here is the reason from the designers:

http://www.freepatentsonline.com/6357782.pdf

Sometimes it takes some time to decipher a patent, but I'll see if I can... it appears to be skating related of all things.

[lilcliffy]

Xcountry ski designers have been playing with reverse side cut (i.e. narrow, straight, tails/tips, wider underfoot) for some time. The basic idea is to be lightening fast in the tip/tail glide zones, but wider underfoot for traction/kick. This concept would only work with a very stiff double-cambered track ski. The wider traction zone is completely off the snow during the glide phase. If that reverse camber rides on the snow- weird thangs are going to happen- not exactly a good off-trail design!

My two cents is that this 5-point sidecut is an experiment to try and play with a reverse-sidecut underfoot, without completely losing some flotation and turn-ability. Strange idea- it would be impossible to engage the front and aft sidecut in a carved turn, without also engaging that reverse sidecut underfoot.

Have you tried them out yet? Would be very interested in how they perform on the downhill.

[Johnny]

Mike, you're my hero...!
I knew you would come out with some sort of cool theory, but now, the full patent...! Woooaaah...!

I didn't try them on the downhill yet... They were super cool on the flats, I was jumping and bouncing all around... But that was before I noticed the sidecut... I dunno, I don't feel like this is gonna turn easily...

But this would be a great idea for larger, powder and downhill-oriented waxless skis... A larger waist wouldn't affect turning in the BC, but it could improve the grip a lot on the uphill... Hummm... It gives me fresh ideas about a new skin system, on the sides... Hummm...