gs style
Some examples of GS race boards for comparison: 04/05 specs Nidecker
Custom GS
177 F2
Speedster
177 Donek
GS
175 Donek
GS
180 Coiler
PureRace
178 Coiler
PureRace
181 Prior
WCR
175 Prior
WCR
181
Eff. edge 159cm 160cm 164cm 164cm 160cm 163cm 156cm 161cm
Sidecut 13.5M 15M 13.2M 14M 13.2M 14.2M 11.9M 13M
Waist 19.5cm 19.2cm 18.5cm 18.5cm 18.3cm 18 or 19cm 19.5cm 19.5cm
Taper 0mm 0mm 3mm 0mm 4mm 4mm 2mm 2mm
Freecarve
04/05 specs Donek
Freecarve 171 Donek
Freecarve 179 Coiler
Freecarve 173 Coiler
Freecarve 178 F2 Silberpfeil 172
Eff. edge 155cm 163cm 155cm 160cm 156cm
Sidecut 11.2M 11.2M 10.5M 10.5M 11M
Waist 18cm 18cm 18.5cm 18.7cm 18.4cm
Taper 0mm 0mm 0mm 0mm 0mm
All-Mountain
Some examples for comparison: 04/05 specs Donek
Axis 167 Donek
Axis 172 Coiler
All Mt 169 Coiler
All Mt 172 Prior
4WD 169 Prior
4WD 174
Eff. edge 143cm 148cm 145cm 148cm 142cm 147cm
Sidecut 9.6M 10.3M 9.9M 10.5M 9.5M 10M
Waist 21.5cm 21.5cm 19, 21.5, or 23 21.5 or 23 21.4cm 21.4cm
Taper 4mm 4mm 2mm 2mm 4mm 4mm
Boardercross (BX)
Stiffness, Length, Sidecut
For each type of board (race, freecarve, all-mountain, etc), stiffness, length, and sidecut are related and primarily determine how the board performs.
Stiffness: The lengthwise stiffness for a given flex pattern is measured by placing weights at the binding locations and measuring the deflection of the board while it is supported horizontally at the tip and tail. It is import!ant to get a board that has the right stiffness based on your weight so that you can decamber it properly when you are in the middle of a turn. Stiffer boards require more weight or harder carves to decamber. If you weigh more, you need a stiffer board. If you intend to carve hard GS turns, you need a stiffer board. There is no standardized measurement for stiffness, and each manufacturer has a different metric. Donek has a "stiffness index" for its boards on the spec sheet. Manufacturers often do not indicate the stiffness of a board at all: in the case of production boards, stiffness is implied by the type of board (race, freecarve, etc), and the length (longer = more stiffness). The SWOARD and the Virus custom ExtremeCarver are the only non-custom boards on the market to offer multiple stiffnesses for each length.
Length: There are three parameters related to length: Total length
Running length
Effective edge
The total length is the tip-to-tail length, usually along the surface of the board (not the chord length). Running length is the length along the edge that will be in contact with the ground when laid flat, between the upturned nose and tail sections. Effective edge is the length of the edge in contact with the snow when the board is decambered in a turn, and is usually a bit longer than running length, since a small segment of the edge in the nose and tail can be used as part of the sidecut. For carving, effective edge is the most import!ant length measurement, and depends on both the overall length and the type of board. Race boards are designed to maximize the amount of edge in contact with the snow, whereas all-mountain boards have a more upturned tip and tail, which raises more of the edge off the snow. A board with more effective edge provides more grip and therefore more stability at high speeds, but is more sensitive to chopped up terrain. Longer boards are also faster, because the force is spread over a greater length. Shorter boards tend to be more squirrelly at high speed, but are more maneuverable, provide better response, and are somewhat more forgiving. If you need to skid your way down a section that you can't carve, it will be more difficult on a longer board. For hero snow, you want a longer effective edge to take advantage of the better grip. For chopped up snow, you can use a board with a shorter effective edge that is more maneuverable. As an example: On the Donek spec sheet, the Freecarve 171 and Freecarve 179 have the same sidecut radius, but different lengths - the longer board will be more stable when carving, but less maneuverable in chop.
Sidecut radius: The sidecut radius is the approximate radius of the curve that defines the board's edge when the board is laid flat on the ground. The sidecut radius is a measure of how tightly the board will want to turn.
Small sidecut radius boards such as slalom boards want to make small-radius turns at low speed. If you push them beyond a certain speed, the G-force from the turn will try to push them into making a larger arc, and they won't be able to hold an edge, resulting in a chatter or wash-out. Large sidecut radius boards like GS race boards want to make large radius turns at high speed, and let you cruise big arcs. They won't start to carve until you get them up to a certain speed, which means you may need to burn up more terrain when starting down the hill before carving, otherwise you will either tip over or skid out. Smaller sidecut boards are good for crowded slopes where you need to slalom your way around people at lower speed, or for resorts that have narrow runs. Get a large sidecut radius if you want to go fast on a wide run during the week when few people are on the slope. Some manufacturers have introduced "racecarve" boards with a sidecut in between a GS board and a freecarve board.
The actual radius of a carved turn (the decambered radius) is tighter than the sidecut radius and is a function of the sidecut, how high the board is tilted on edge, the stiffness of the board, and the rotational torque applied by the rider. You will get a smaller radius turn with a smaller sidecut, higher inclination, softer board, and more rotational torque. It is possible to muscle a large-sidecut board into a smaller arc, but you can't force a small-sidecut board into a bigger arc. If you get a large sidecut board, you can "grow into it" as you gain more carving skill - you will be able to narrow the decambered radius as you get better.
In order to make the board follow a path that is circular (or elliptical) when decambered on the snow, it is necessary to use a sidecut shape on the board that is not a circle. Which means that board manufacturers use a sidecut that changes along the length of the board, using one of two methods:
Using a mathematical curve: Conic sections, Quadratic, Elliptical, Parabolic, etc. The average radius of the sidecut curve is different at different points on the board, and determines how the nose, tail, and center of the board hook up with the snow. For instance, Donek boards have a combination of flex and sidecut that allows them to grip well on ice by transmitting pressure to the nose and tail.
Using a progressive sidecut that starts out larger near the nose (to make it easy to enter turns), then changes to a smaller radius near the tail (to provide acceleration, like a slingshot). The Volkl 3D sidecut is one example. This design is often used for BX boards.
Sidecut Depth: The distance that the sidecut intrudes into the board, measured from a line connecting the widest point at the tip and tail to the deepest point on the sidecut. Greater sidecut depth (smaller sidecut radius on a larger board) results in a board that is more hooky. There is sometimes ambiguity when people use the term "sidecut," without a qualifier, since they could be referring to either sidecut depth or sidecut radius. Plus, some people consider a small sidecut radius to be more "extreme". When people say "that board has more sidecut," they usually mean a smaller sidecut radius and more sidecut depth (a more extreme sidecut).
When selecting a board, your weight directly determines only the stiffness of the board that you select - it does not directly determine the length or the sidecut. Manufacturers don't usually give stiffness metrics for their boards, so the only way to measure it yourself is to get your hands on the board and flex it. Since this method isn't so practical, the actual selection of a board depends on whether you are looking to buy a production board or a custom board:
For a production board, the length, stiffness, and sidecut radius of a manufacturer's production lineup are correlated - the longer the board, the stiffer the board and the larger the sidecut radius, which means that your weight will also happen to correlate to length, so you can buy a board by selecting a length based on your weight. However, it is import!ant not to buy a board based on your height - the slackers at the board shop seem to have the misconception that height corresponds to length.
For a custom board, the board manufacturer will suggest a starting point for stiffness, length, and sidecut optimized for your weight and riding style. Then, you get to tweak the parameters more or less independently within allowable ranges. For instance, you could ask for a long 185 cm board with a short 11 M sidecut, but the longer board may stipulate a certain minimum stiffness.
After stiffness, length, and sidecut, the other significant characteristic is tail spring. Boards can be either lively or damp:
A lively board will provide snappy tail spring at the end of each turn to launch you into the next turn so that you get a trampoline effect. You can also "pump" the board at each turn to tap into the energy. A lively board requires a little more skill to handle, since the energy can throw you if you don't handle the rebound. A lively board is ideal to have on hero snow. However, it will not hold quite as well on ice or crud, and is slightly more susceptible to chattering and skidding.
A damp board will provide less tail spring. It provides better edge hold on ice, and you are less likely to experience chattering. However, it will not provide a lot of tail spring to launch you into the next turn. It's easier to learn new skills on a damp board - then, move to a lively board and try leveraging the "snap."
Your style will determine whether a damp board or a lively board is ideal for you: if you do a lot of slalom-type cross-under, you want a lively board that easily crosses under you on each turn. The Hot Blast and Volkl Renntiger are favorites here. If you use a GS cross-through style on a rutted slope, you may want a damp board like the Oxygen Proton that will keep the edge in the snow as you shift your weight over it.
You can get an indication of the tail spring by holding the tip of the board off the ground with one hand and bracing the tail on the floor with your foot. Then, with your other hand, flex the board and see how fast it springs back.
Whether a board works for you depends on your specific riding style and skill level, so you really can't rely on reviews from other people. When you demo a board, you will want to compare it side-by-side under the same conditions with one of your existing boards, since binding setup and snow texture have a huge impact on board performance. When you have a chance to demo a board, try to determine what subtle changes you need to make to your riding style to get the best performance from the board. That is the best way of eval!uating a board, and it's also something that's included in the best reviews.
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