The 3 diagrams above are enlarged scale drawings. This is known as the 60mm rule. The actual truebar pictured above the diagrams has a mark located 60mm from the square end of the bar, and is the ultimate tool in determining the present status of your product. One well known device that utilizes this rule is the one degree SVST Final Cut Base Bevel Guide. It proves that the truebar may not rise off the base more than a maximum of 1mm to equal 1 degree of base edge bevel, period. This formula is strictly math and therefore may not be argued. It is the ultimate verification in determining if your shop has done a correct job. It is THE formula that is the foundation for all work performed at SkiMD! If your shop is reluctant to verify their work, perhaps it's time to look elsewhere.
It is a fact that a properly finished base edge angle residing between .5-1.0 degrees, allow all categories of skis and snowboards to perform at their best. No ski factory recommends base edge angles to exceed 1.0 degree! SkiMD produces all base edge angles with a median tolerance of 0.75 degrees. If your skis or snowboard are reluctant to go right and left, or wander when going straight, it means you have too much base bevel or an improperly finished base structure. SkiMD produces side edge angles at 2.0, 3.0 and 4.0 degree. 2.0 degree is used for jr. skis and powder skis. 3.0 degree is used for narrower performance recreational and race skis, while SL and GS skis have the option of being produced at 4.0 degrees. More factories are realizing that it’s worth the hassle to recalibrate side edge machinery to this parameter. Why? Because shaped skis are able to achieve higher tip angles with greater leverage than straight skis. As a result, skis with less than 3 degrees of side edge will have a tendency to chatter and become duller quicker as a result of skidding more and cutting less. Never let anyone try to convince you that this is too radical, or that it gets duller quicker. No information exists to support that theory. The difference in material removal between a 3 or 4 degree side edge angle is truly minimal over a side edge height of 2-2.5 millimeters. However, the difference in performance when asking your skis to do what you want is profound. If your skis or snowboard chatter when tipped on edge, it means your side edge angle is incorrect.
Installation of the correct parameters cannot begin without the proper diagnosis of the base and edge finish. This is accomplished by utilizing a “hairline trubar.” It’s not a “square edge rectangle” or a “rolling pin,” as its edge is almost knife-like. This creates an optimum visual reading that does not lie. Utilizing a specific geometric equation as to what a 1 degree base edge angle looks like, determines the pre-existing edge finish. One may locate a trubar with the proper equation from Sun Valley Ski Tools. Ask your favorite retailer to show you how this works before you send your skis through the machine. The photo on the right shows the actual distance the bar must rise off the base to indicate a .75 degree base bevel. A 1.0 degree base bevel would make the bar rise off the base only another .25 millimeters!