Edge Beveling: What’s your angle?

There's a lot more to snowboard-edge maintenance than dragging a file down the edge 'til your arm gets tired. Good edge tuning requires that the file's driver has a basic understanding of edge beveling–and a plan.

Beveling is the process of precisely angling each of the four edges of a snowboard to alter its turning and edge-holding characteristics. Four edges? I know at first glance it seems I could use some remedial math classes, but in reality, each single board edge is actually made up of a base and side edge.

These edges start out life as perfect 90-degree angles. By altering this right angle it's possible to adjust, or tune, a board's performance characteristics to suit any rider's style or the local conditions. Changing the angle of the base edge alters a board's turning personality and modifying the side edge adjusts the board's ability to grip while in a turn.

Both of these edges are beveled by positioning the file on the edge and removing just enough metal to change the 90-degree angle. The angles are measured either parallel to the board's base (base edge) or perpendicular to it (side edge).

We're not talking about big adjustments here. In most cases the amount of angle is measured in single-degree increments. For instance, it's common to bevel a base edge just one or two degrees and a side edge from one to five degrees. The combined angles of the two edges is referred to as the overall edge geometry. I'm no authority when it comes to angles, but if the side edge is four degrees and the base edge is one, it works out to 90 – 4 = 86 + 1 = 87 degrees. Whew.

Remember, the side edge is always subtracted while the base edge is added. An acute angle is preferred in most circumstances because of it's more knife-like point. Avoid bevels that will produce an obtuse angle; a greater than 90-degree edge in firm conditions is frightening due to its lack of gripping ability. In neck-deep powder it simply doesn't matter.

So what does this all mean? Well, the basic idea is the closer the base edge is to 90 degrees (parallel to the base plastic) the quicker the board wants to engage in a turn. Very little rider input is needed to get the edge into the snow and the result is a quick-turning, lively ride. Conversely, if the edge is beveled a degree or two, it takes more rider input to angle the board enough to get the edge to engage.

The right amount of base bevel changes from one pilot to another. A general rule of thumb is go flat (no bevel) on the base edge if you really want the board to snap from one turn to another, and add a slight bevel if you prefer a mellower ride. If your speed commonly runs at cheek-flapping velocities, an extra degree or two of base bevel will tend to temper the ride just a bit and may prevent those crushing slams that result from sudden, inadvertent edge engagement.

Side-edge tuning is much simpler in that you are merely controlling how well the board grips once the edge is engaged. Simply put, if you're likely to encounter glazed, bulletproof conditions, by all means add side-edge angle. If, on the other hand, the conditions are a little more fluffy, the side-edge angle can match that of the base edge for an edge geometry of 90 degrees.

Back in Vermont it was common to run between zero and two degrees on the base combined with three to five on the side edge. Out west, where the snow tends to be a little softer, one degree base-edge bevel with one or two on the side is adequate as grip is much less important.

Any discussion of beveling must also include a few notes regarding detuning, or dulling, certain areas of the edge. These usually involve the corners, or contact points, of the edge. If left razor sharp, the ride can become unpredictable and erratic. Most ordinary folks find a little mellowing of the corners allows the board to tturn and spin more smoothly.

To find the contact point, place the board base-down on a smooth, flat surface. Press it flat and slide a piece of paper or a business card under the edge until it's wedged between the edge and the flat surface. Mark all four points (both sides, tip and tail) with a marker. Detuning an inch on either side of the contact point is common, but experiment to find what suits your style. Avoid over-dulling the edge; it's easier to detune a little more than to try bringing back an edge that's been really rounded.

If you're wondering why all this is necessary on a board that supposedly came pre-tuned, remember, factories are only able to finish a board for general conditions. Beveling and strategic detuning of the edges will unlock performance that would otherwise remain hidden and can go a long way toward pegging the fun meter.

Is there something you always wanted to know about prepping your board? Doyle's done it all. E-mail him at tech@twsnet.com (Ask him what he does with Terje's board).

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