By: Motorhead Mark Lester
What is ski-lift? In elementary terms it looks like this: You set up for a turn then suddenly, without warning, your sled hops up onto one ski and all your predetermined reflexes require instantaneous recalculation. You compensate for what feels like a sled about to roll.
Most often you lean harder to the inside and instinctively dial in less turn angle. This puts the sled on a wider arc through the turn. If the trees are coming up too quickly, a handful of brake will reel things in. All this is accomplished in an instant thanks to your amazing reflexes.
Sometimes inside ski-lift is desirable. In fact, no sled corners perfectly flat all the time. Reality is this: a low CG and a low roll centre (the theoretical longitudinal center of the sled) generally produce the best cornering response. In other words, if the CG and roll-centre are in the sweet spots, inside ski lift is a manageable and most importantly, predictable reaction to an aggressive clip through the twisties.
It’s no secret this year the Yamaha Nytro displayed some ski-lift. The Nytro’s handling was by design very edgy and aggressive requiring sharp reflexes if the throttle was wicked in tight trails.
Although the Nytro is the lightest ‘08 4-stroke sled, it does have what appears to be a fairly high CG. This cannot be changed with over-the-counter parts. After we spent some time with the sled, we wanted to slow down the handling a bit and keep things more level.
First we touched up shock air spring pressure then zoomed-in on the skis, trying a number of things to ease initial turn-in. Different ski profiles and carbide combos led us in different directions. However, we stumbled onto a product so convincing we were amazed. Snow Tracker (snowtracker.com) makes a “self sharpening” carbide runner that bolts onto Nytro skis in addition to a weird looking steel “U” plate.
Honestly, the whole thing looks so strange we had serious doubts about its ability to do what was promised. We were wrong. The concept is sound and while some engineers we’ve spoken to believe Snow Trackers increase steering effort under some circumstances (they are correct) this, in our opinion, is a small trade-off for the improvement in stability and linear, controlled turn-in. The Snow Trackers hold a precise line when entering corners so darting no longer interferes with your steering inputs.
There are other ways to soften initial turn-in and control darting on not only a Nytro but any dart prone sled by using dual carbides and different ski profiles.
Clearly the move to multiple tracking points on ski bottoms (like the Simmons design, BRP’s Pilot and Precision models) have a profound effect on controlling unwanted darting and thus reducing ski-lift.
My point here is this: There’s a lot of great sleds in the market that have varying CG and roll centers. You cannot easily alter these built-in chassis parameters once you take your sled home. However, the inputs from dart-prone skis that initiate ski-lift and aggravate darting can be altered.
More answers have come as we’ve racked up miles this winter. We’ve installed USI boards with Stud Boy Shaper Bars on a couple of sleds and seen huge improvements.
Our Jaguar Z-1 and F-8 Arctic Cats have the inverse of darty behavior. They display annoying understeer or “push”. By bolting on a more aggressive ski we’ve turned these sleds into confidence inspiring trail rides. Interestingly, Arctic Cat has made significant geometry changes to the ’09 Twin Spar platform to rid the F of understeer. In a similar way Yamaha has reconfigured the Nytro’s front end geometry and it too is vastly settled for MY 09.
Another interesting discovery was the use of USI skis and Stud Boy Deuce Bars (double runners) on our Vector LTX 136. The sled handled quite well out of the box but clearly the skis were dart-prone and created unnecessary inside ski-lift in twisty trails.
The ski and skag combo virtually eradicated darting on tracked-up trails. Initial turn-in was softened somewhat but, by mid-turn, the Veck was happy and biting predictably to the exit.
We’ve had more inquiries about this topic than ever before in a year when more sledders have been on the snow than in recent memory.
There’s more ways to reduce inside ski-lift than just those mentioned here. Lowering front ride height and altering ski pressure, not to mention dialing in a little toe-out (toe-in is guaranteed to produce darting regardless of skis, carbides or any other set-up), are effective ways to generate handling improvements.
Here’s what we know for sure. A little fiddling and maybe a set of carbides or skis can net a big improvement in the way your Snow Bullet clips apexes.
The issue requires some patience, a rudimentary understanding of where you’re at and what direction you need to go in order to get improvements.