Bottom Edges (Bevels?)

[JAYK]

So I need some education on bottom edge of skis if someone could be kind enough to share their knowledge. How does the different edges and combinations affect the characteristics  of the ski? The Fischer has rounded edges, the Monza has 45deg to a rounded tail, the SS has 45 deg throughout, and the Goode I didn't pull out of the bag to find out. Thanks in advance!!

[Horton]

Jay,

You are kind of wondering into the alchemy of ski design. In basic terms sharper edges push the ski up and round edges make the ski ride deeper in the water. The problem with trying to predict how a ski rides only based on edge shape is that bevels are only one of many parameters. Profile shape, thickness, sidewall angle, twist (of lack of), bevel width/radius,  tensional flex and longitude flex may have as big or bigger affect on how a ski rides.     

I think a good analogy is that it is like judging a car purely biased on horsepower.  A Dodge charger may have more horse power then a Lotus Exige but . . . . .

I do not recommend ever sanding your bevels unless you have a dozen skis and you do not mind wrecking a few.

[JAYK]

Thanks for that info, now that can of worms just got way BIGGER!! Any idea where I could get a ski design 101 lesson or resources to educate myself besides torturing everyone here? 

[Horton]

Ski Design 101? Sadly no. I think a lot of us are pretty interested.  Heck, I would buy the beer to listen to a real ski designer give a lesson.

 

If you ask specific questions you might get some answers. I know that factory guys check this forum. Getting them to comment is another thing.

[BillBarton]

If you do some mining on Steve Schnitz's site you're going to find some articles that get pretty deep into the science. The guy has a lot of knowledge in that bean and has written quite a lot of it down.

[eleeski]

Sharp edges lift, round edges suck. A sharp bevel will resist rolling the ski on edge and a round edge will roll it over. But Horton is right, the edge is just one small factor in ski performance.

The days of "file on" edges (a real ad from one of the LaPoint designs of the past) are gone. Now you fine tune with binding and fin settings. The modern skis don't have much material to file on the edges. Also, the edges can be important for structural integrity of the ski. So be very careful before filing your edges. With that said, I add material to my edges so I can grind on the edges. My edges are asymmetric. The edges are a smaller effect than fin adjustments but they can be better tailored for onside offside. I have gone too far with the grinder but some Superfil cures that problem.

Don't pick any ski based on physical properties. There are so many balancing factors that the only way to really know how a ski feels is to demo that ski. The file is the last tool to use to perfect a ski.

Eric

[Horton]

Holy Crap! I never believed I would see the day! I totally agree with Eric!

[JAYK]

I appreciate the fact that going out and skiing on it would tell me how the ski feels and I'm in no way interested in filing down a ski, well maybe a little but I'm pretty sure the wife would kill me on the spot for ruining a ski which is probably what I would wind up doing in the end!

Just really would like to know how all these "factors" affect the skis performance. If you can measure all of these you should be able to come to some type of conclusion as to how and why a ski acts the way it does? I'm the guy that wants to know all those "balancing factors" and there outcome. 

Thanks for the replies!! 

[Phil2360]

Have a look at Andy Mapple's Slalom Video.

He talks for a good bit & shows how to file bevels.

He also points out his huge collection of ski's that maybe were filed a bit much.

Phil

[eleeski]

I've often filed too much on my skis. And some skis have needed material added rather than a file. No big deal. That's what bondo or superfil is for. But since you can't easily measure or reset an edge, filing is an art - not a science.

 

Exhaust the other tuning options first. Then do the fine tune with the file if you really need it. If none of that makes the ski feel right, get a new ski.

 

Eric

[Horton]

With some of the super light skis the carbon/epoxy skin is very thin. The bevels hold part of the structure. I have seen a Goode break because of filing. If you are going to file do it on a “heavy” ski.