ski tuning techniques

[eleeski]

I've been playing with the edges on my latest experiment. I am surprised how much tuning can occur with a little bit of Superfil and some sandpaper. The thickness of the side of the ski, the softness of the top edge, the angle of the side, and the softness of the top bevel edge are all parameters that can be adjusted for specific performance effects.

A very cool aspect of the superfil / sanding tuning technique is the ability to adjust just one side's turning characteristics without changing the other side. My 2 4 6 was working well but 1 3 5 was toxic (dumping me in). Sharpening just the left bevel cured the problem but left the 2 4 6 the way I liked it.

Perhaps the manufacturers could add a bit of fileable material (a la old LaPoint skis with their 'file on" edges). Competent tweakers - like those on this board - should have no problem tuning edges. It's another tool, and one without as many tradeoffs.

Eric

[DW]

How about a cause and effect documentary on what effect each of your tuning changes had on the ski.

[Horton]

also how does Steel.

Reserve effect the result?

[eleeski]

The problem started when the ski was diving into the water in the turn. I wondered if a thicker edge in the front of the ski would help things. So I added some Superfil to make the ski thicker in front. It helped a bit. On the theory that if a little is good more is better (the Steel Reserve conjecture) I thickened it up more with another application of Superfil. Now the ski wouldn't turn. So I sanded off the second course of Superfil. Actually, I used the grinder and didn't do a very pretty job but the ski worked - sort of but it was really slow. I decided to grind off the ridges on the bottom (unrelated change but bear with me). It was pretty ugly and I was getting flamed for my ski cosmetics so I broke out the Superfil to hide the grinder marks. I also dressed up the edges. The ski is still ugly but it turned 2 4 6 really well. But 1 3 5 was really weird and bouncy. So I smoothed out the left edge of the ski with a sanding block. Now it wouldn't turn at all on 1 3 5. So I softened the top left edge - and the ski now dove again on 1 3 5. So I sanded the left edge at a 5 degree angle from vertical (OK I didn't measure - that isn't quite vertical so it looks OK. This also left a much sharper edge on the top edge of the bottom bevel. Now the ski is balanced and turns well on both sides.

Thicker edges - more speed in the turn and the ski turns a smoother but wider arc.

Rounded or soft top edge - tighter turns and a slower ski.

Bottom bevel sharpening - faster ski and wider turns.

The effects were more dramatic than fin adjustment - but messier and more time consuming.

All fun,

Eric

 

[BuoyChaser]

got any pics of "superfil" and where to find it???sounds like a great fix as well for "handle pop marks"...

[eleeski]

http://aircraftspruce.com/pdf/2007Individual/Cat07042.pdf

Aircraft Spruce has it for mail order but I get it in stock from the local aircraft supply shop (El Cajon Aircraft Supply) in San Diego. It is easy to work with and very light for a non-structural filler. The only drawback is the long cure time - especially when it's cold.

Eric