3 ways stock skis make your sled dart

There’s a good deal of literature floating around the internet on what causes snowmobile darting, and people selling you solutions to fix it.  Let’s face it, darting ruins snowmobile rides by tiring riders out too early, and it can be dangerous, especially as it wears you out and your sled is jumping around the trail.  Most of us are willing to throw a little change and elbow grease at it to make darting (or hunting) go away forever.  Though it’s too often people never address it properly and they just don’t enjoy riding as much, and as a result, they DON’T ride as much!

We’re snowmobile enthusiasts but we’re also engineers, so we set out to understand the physics and mechanics behind darting. Then we set out to build the ultimate ski and handling configurations that minimize the risk of darting. But that’s a separate conversation.

Today we’re going to share with those who are interested how we’ve seen many snowmobile ski designs, by all the manufacturers, continue to make darting the default handling characteristic of a snowmobile riding through a previously well ridden trail.  

First, what is darting?

Darting occurs when the sled’s steering is responding to the direction of even small ruts in the trail rather than your steering input. As the sled encounters new ruts, it’s shifted in an unpredictable side-to-side manner.  The sensation of darting is felt by the rider in the form of skis feeding lateral steering forces back up to the handle bars.  In order to correct course, the rider is required to constantly deliver frequent forceful steering inputs, and doing this in a system that is already not very responsive to the riders input.  

  1. Square edges.  
    1. Square edges love to find slots. Think of a flat blade screwdriver and screw, or a tire in a rut…the physics of minimizing potential energy means it will fall into place given the opportunity to do so. This means that a square edge on the side of a keel will gladly find itself at home while inside of a rut, no matter how big or small.  
    2. Flat surfaces can only apply perpendicular forces. This causes a real problem when you’re trying to get a ski with square edges out of a rut, and is a primary contributor for the rider needing to exert extra force to get out of the rut.

  2. Passive, rather than active geometries.  What we mean by active geometry is that the ski is shaped such that it is manipulating the shape of any available snow as it travels over it.  Moving snow with the ski is what causes the controlled friction needed to allow any steering forces to take place.  A passive geometry means that the geometry of the ski isn’t doing any work on the snow.  Guess who is left doing the work on the snow?  You!  

  3. No erasers.  Which means the ski keels to be subject to whatever was left on the trail before you got there.  This is especially problematic when there is significant icing after ruts have been formed on a trail, the snow is less able to be manipulated a ski, even one with an active geometry.

Coming up next will be a post on how we designed the ultimate ski to combat darting.
As always, feel free to ask us any questions about darting, skis, etc. On Facebook or the bottom right corner of the site. 

If you're like us, a trail rider who likes to hop off trail from time to time and play in the powder, we think you'll love how Curve skis solve your darting issues once and for all, while bringing your sled the epic ride.  Which is why we continue to offer a money back guarantee if you're not satisfied.

-->  Curve XS Package

Leave a comment

Please note, comments must be approved before they are published