Sometimes, when diagonal striding, the tails of your skis will make a slapping sound when they land in the track.
In my early days of learning how to ski a coach said to me,
“Hear that clapping sound? That’s applause for bad technique!
Maybe you’ve heard the same thing from your coach, or maybe you’re a coach and have said something like that to one of your athletes. It seems to be a common concern among skiers and I often hear people worrying about “tail slap”.
The idea behind the if-your-skis-are-slapping-your-technique-must-be-bad theory is that it’s supposed to be a fail-safe way to tell if a skier’s hips are too far back. In theory, when the hips are back, the tail of the ski will slap down on the track with each stride because the skier’s recovery foot is landing behind his stance foot, rather than beside or in front, which is optimal.
It can be challenging for an instructor to diagnose a skier’s underlying technique problems, so it would be really great if this were a quick and dependable indicator of a specific problem. Unfortunately, the if-your-skis-are-slapping-your-technique-must-be-bad theory fails in 3 ways, which pretty much makes is useless to both skiers and instructors.
What’s Wrong with the “If-your-skis-are-slapping-your-technique-must-be-bad” Theory?
1. It’s Incorrect
The main problem with worrying about noisy skis is that it’s completely normal for skis to slap down on the track in certain circumstances. Skiers with perfect technique and great hip position will experience tail slap on certain terrain.
Here’s the proof. The video below was taken at the 2014 Canadian Ski Nationals. You can hear how numerous excellent skiers had “slapping tails” on this section of the race course. Their hips are fine and their technique is awesome. The angle of the hill and the optimal way to stride it just happened to cause “tail slap”.
The video shows 8 skiers, but I could have included at least a dozen more racers. Clearly slapping skis don’t slow you down and are nothing to worry about.
(Sound warning: you won’t to want to watch this video more than once. It was a windy day and the sound was recorded with the video camera microphone. It’s a little hard to listen to. I’m sorry!)
This video should lay to rest the idea that we should worry about tail slap, but just to make sure it’s really dead, I’ve got two more reasons why we need to give this theory up.
2. Talking about a skier’s clapping skis can have unintended negative consequences for his technique
If you tell a skier his skis are slapping and he needs to make them quieter, he will fix the clapping sound, but you won’t like what it does to his technique.
Even if you tell him “all” he has to do is keep his hips forward and it will go away, he won’t instantly have awesome hip position, but he will start to be self-conscious about the noise. The sound will bother him and he’ll probably make a couple of adjustments which will worsen his technique.
One change he might make is to “step” his recovery leg forward instead of using a more relaxed swing. The other thing he might try is to quiet his skis by skiing more timidly. This will interfere with his ability to get a strong kick.
Either way, it won’t be good.
3. Excellent Skiers Sometimes Slap Their Skis on Purpose
Fresh snow has a tendency to ice up your kick wax. The pointy, sharp edges on the snowflakes dig into your wax and that “seeds” the formation of other crystals so that you end up with icy patches in your wax.
These are a terrible bother because the snow will build up under your ski and it will be impossible to glide. In the worst case, your ski will stop dead in the track when you least expect it but your body will keep going and you’ll tumble head over heels.
You can combat this problem by deliberately slapping your recovery ski against the snow as you swing it forward. The more you slap your ski against the snow the better you’ll shear the clumps of snow and ice off your kick wax. In this case, slapping skis are a good thing and will help you.
I’m done with that idea. I hope you are, too.
To sum up, while it might occasionally be true a skier’s weak diagonal stride technique and poor hip position will cause his skis to make a clapping noise, it’s not always true, and it’s never a helpful thing to point out. For the most part, it simply doesn’t matter.
Sometimes bad ideas stick around for a long time. Simple ideas can be particularly compelling, and therefore, more enduring. Slapping ski=bad technique is a simple, bad idea that’s been around for way too many years.