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Adding Tip Weight


ozski
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Just wondering if anyone as ever thought of or tried adding weight to the tip of the ski as a tuning measure? I wonder if it would help keep the ski in the water for those skiers who tend to stay back? What other characteristics might it change? I know its a little out there but I'm not talking about adding a house brick either. If we are talking small binding adjustments and fin changes what about a few grams of weight up front? Thoughts? Has it been done?
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Not recommended imo. The weight would probably need to be substantial to be noticeable. When/if the ski gets airborne of the wake one might think the weight effect would be most noticeable enhancing the chance of a nasty tip stuff/OTF off the 2nd wake.

 

Improved balance and stance are best remedies.

 

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@ozski‌ add 10 pounds at a time and keep a video record of each ride. We really want to see.

(hmmm no this is a terrible idea - if you are on a reasonable ski => fin and binding adjustment is all you need)

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The basis behind adding weights is to reduce vibration in a structural component. The weight usually isnt very significant. The A10's tried adding an 8lb weight at the end of that giant gun to reduce vibration at a certain fire rate which causing the gun to break free from the mounts. The F15's have a few pounds on the tip of the big vertical stabilizers to prevent the vibration frequencies from aligning. It doesn't actually reduce the vibration itself. What it does is change the vibration frequency so that it's not in the same wavelength as the natural frequency. If the two frequencies align, they amplify each other and cause bad things to happen. Ski's aren't really in a vibration critical state for very long so I can't see it doing anything positive or even noticeable. The type of bindings you use probably has a greater effect.

 

Others may know better on the ski side of the house but my understanding is that ski manufacturers make ski's that have a dampening effect as a detuning effect so it's more user friendly.

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Adding tip weight also significantly increases the angular moment (aka swing weight) of the ski, which most likely makes it significantly harder to turn. I think that's the last place you want to add weight. Indeed, several manufacturer use sneaky methods to REDUCE tip weight, since that's the spot that makes the largest contribution to angular moment (since it is furthest from the center of rotation of the system -- aka the skier).
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@Than_Bogan‌ may be on to something though. If you can figure out where the true pivot point of your ski is, you could add weight behind it to change how the ski reacts in the turns without changing the fin. Call it a quick tune that moves in small increments for fine tuning the ski on the fly or between passes. Could be a neat concept.
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I stopped skiing with a GoPro on the tip of my ski because it made the ski feel ponderous. That fall, Jason McClintock told me he thought it was costing him up to a pass before he took his GoPro off the tip of his ski.
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@ozski‌ I commend your thinking out of the box. Personally lighter works better for me. But strategic weight balancing might be useful. Try small weights. There is a ball bearing in oil damping system you can buy which would be really interesting. I would be careful during testing as weight at the end of the ski will add lots of torque to any flailing fall. Do keep us posted.

 

@Than_Bogan‌ doesn't quite have it right (he is right for trick skis). A slalom ski only needs to change 180degrees and you have a relatively long time to finish the turn. The actual turn has the ski sweeping an arc with a couple meter radius at best. The all up weight of the ski (including the bindings) will affect the turn. Maybe the skier weight matters significantly as well.

 

@SkiJay‌ Interesting observation.

 

I prefer light skis. At slalom speeds, the water damps vibrations fairly effectively. Weights on aircraft ailerons and rudders counter forces that generate dangerous flutter. The weight on a a sailboat counters the force from the wind. The tip of a waterski needs to move quickly in many axxes (axises?). Weight, especially at the tip, will interfere with this movement. Any straight line damping will be overshadowed and perhaps enhanced by perturbations (like the wake). Bottom line - all the top skis are light and getting lighter.

 

Eric

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@AB When I put my 60 pound kids on the front of my skis, I had a great ski ride. Didn't score any buoys or make any tricks but it was the most fun!

 

I took a trick ride with diving weights on once but I was too worried about falling and sinking that I didn't have much fun. There really are differences in what kind of weight it is.

 

Eric

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And they all laughed at me!

 

"Stability Tuning is something we’ve been playing with for a long time and we're finally ready to put it into production on this V-Type water ski. Working with Chris and Bob LaPoint has been awesome as they’ve been around through the years of wood construction to fiberglass to now carbon construction. The move from Fiberglass to Carbon was a big transition as the a carbon water ski is so reactive and snaps back so much quicker making the ski faster off the buoy. Everyone agreed, “This is the future, we need to make skis out of this stuff.” But the downside with carbon is that it reacts too quickly in the front of the ski. It provides too much chatter and noise (or feedback) to the skier, so the ski can actually feel a bit too unstable. We’re now introducing a stainless steel tip weight that sits on a damper pad, and screws right into the nose, or shovel, of the ski. The V-TYPE is the lightest ski we’ve ever made; around 3 lbs. We've found that adding the tip weight to the nose of the ski slows down the oscillation of the tip, or the frequency of the ski, so the ski feels quiet like the chatter isn’t even there. The dampening counter provides an all feel and stability. The weight isn’t real heavy, it’s about 5 ounces, just enough to reduce smaller vibrations. We’ve added a few inserts so you can move it to fine-tune the ski just like you can with your wing."

 

 

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@ozski‌ I'll laugh at them too. At least the inserts are pretty light so the ski will be great once you take the silly weight off.

 

To anyone who gets this setup and evaluates it, please try the oil/ball bearing damper for snow skis ( skihds.com ). Report back (with entertaining video).

 

Eric

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I skied with my go pro on the front of my ski last week and had the best two sets of the year. Not sure what that means. Probably need to get up on the front of my ski better on my offside. Or more than likely just a fluke.
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Anyone remember the Obrian G4 or was it the Vengiance with the power rods incorperated into fin box for tail stiffness adjustment and the slider plate on top of the front of the ski for tip stiffness adjustment? Oh and then there was the little tiny fin under the rear foot for tracking which you could pull off or leave on. Came with a book of adjustments and what does what. Andy had a ski painted up to look like it had the rods and plate up front that year.
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@thager I forgot to mention the weird X shape bottom at the tail and the hour glass shape up front. Ya, the ski had an hour glass shape in front of the front boot. Never had so many OTF in my life.
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I saw Dave Wingerter's ski with the inserts for the tip weight. Neat looking ski. The inserts were reasonably placed a not too far in front of the front binding. I was picturing a scuba weight bolted to the tip of the ski. While he had no weight installed, I was intrigued by the possibilities. I hope he keeps the experiment going as the idea makes too much sense to improve the rough water performance. Getting Dave's formula for weighting vs chop could prove invaluable.

 

Of course the video of the scuba weight on the tip flailing in an energetic fall would still be entertaining.

 

Eric

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