Ceren YuksekWRIT 340 Illumin Assignment

The Science in SnowboardingSnowboarding, a sport that started in 1965, has come a long way. Now as an Olympic sport, snowboarding has a lot of factors that affect the ride. Among these factors are the type of board, weather conditions, and the physics that take part in turns, stops, tricks, and halfpipes. This essay dissects these factors and the evolution of the snowboard.

INTRODUCTION

Snowboarding is a very new sport that started oddly with the Snurfboard in 1965 [1]. However, even though it is very new, it has evolved with new technologies and today it is a main event at the winter Olympics. There is a lot that goes into snowboarding that even many snowboarders aren’t aware of, including the evolution of the board, the way the board is made, and the types of boards and how they affect the rider. Furthermore, the condition of the snow and the physics behind the halfpipe and other tricks are a fundamental part of snowboarding. This essay will help those who want to understand the art of snowboarding better.

THE BEGINNING

The first snowboard, developed in 1965 by Sherman Poppen, was made of two kid’s skis bolted together [1]. As seen in figure 1, it had a rope tied on the tip for steering and a steel track to hold the rider’s feet on the board [1]. Poppen came up with the idea when he saw his daughter trying to stand on her sled while going downhill. He called his invention the Snurfboard and since all the kids wanted one, he licensed his idea and sold millions more.

Figure 1: Poppen and his Snurfboards [1]

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Jake Burton, Tom Sims and Dimitrije Milovich were the main people who further improved theSnurfboard, making it more similar to today’s snowboard. Jake Burton Carpenter, founder ofBurton, added rubber bindings for more control, which replaced the rope that was tied to the tip of the board (1977) [1]. Tom Sims, in the 1960s, added bindings and aluminum sheeting on the bottom of the board and Milovich added a ‘V’ cut out in the tail of the snowboard [1]. In the years after these improvements other changes, such as round tails, plate bindings, hard boots, and other types of boards, were made [1]. One of the most important improvements made was the metal edges that were added and the narrowing of the center of the board to accomplish easier turns [1].

Initially snowboarders were perceived as reckless and dangerous rebels. However, as snowboarding became more and more popular in the 80s, people became more accepting of snowboarding and snowboarders. Ski resorts began opening their trails to snowboarders [1].Finally, in 1998 it became a part of the Olympic Winter Games at Nagano, Japan [2]. Today snowboarding has five sub categories in the Olympics: giant parallel slalom, parallel slalom, half-pipe, slopestyle, and snowboard cross [3].

SNOWBOARDING GEAR

The Board

Snowboards have a wooden core that is surrounded by fiberglass and that has steel edges, which are all attached together with resin [1]. The steel edges are there for turns and for controlling speed [1]. The fiberglass, placed on the top and bottom of the wooden core, is to keep the board stiff [1]. Lastly, there are stainless steel inserts on the top of the board to attach the bindings (hold the boots on the snowboard) [1]. These can all be seen in figure 2.

Figure 2: Parts of a snowboard [1]

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The board can either have a sintered base, or an extruded base [1]. A sintered base is formed when “Polyethylene granules are heated and compressed to create a porous plastic. The higher the grade the greater the molecular weight of plastic, the greater the molecular weight, the lower the coefficient of friction and the tougher the base” [4]. This means that these bases are faster and more long lasting. On the other hand, extruded bases, “created from a single sheet of plastic manufacturing by melting stock plastic then pushing it through a die and rollers to create a uniformly thin sheet,” [4] are slower. The reason for this is because of the low amount of wax they can absorb, which is crucial. Therefore, a sintered base is always better.

When looking at maintenance, having wax at the base (bottom) of the snowboard is very important for two reasons. First, it protects the base of the board from wear and waterpenetration, which is harmful to the snowboard [5]. Second, it reduces wet-drag friction because of its waterproof quality [5].

Another important factor in taking care of the board is the edges of the snowboard. One must make sure that the edges of the snowboard are sharp at all times because of their importance of turning and control [5].

Other significant manufactured parts of a snowboard include the nose, sidecut radius, camber, effective edge, and flex point [1]. When the nose (front end of snowboard) of the snowboard is higher one can ride at greater speeds [1]. When the sidecut radius (depth of board from nose to middle) of the board is small one can achieve tighter turns [1]. If the camber, the area of the board between the front tip and tail, is springy (better for freestyle moves), the board will make turns easier and if it is flat than the board is worn out [1]. If the effective edge, the metal sides of the board, is longer, then the board will be more stable, but if it is shorter than one will be able to perform easier turns [1]. The flex point (between the two bindings) is the beginning or ending point of the flex (flexibility of the board) [1]. When doing bumps a soft flex is better, but if boarding on ice than a stiff flex is better because it has a better grip on ice.

The 3 Types of Snowboards

The freeride/all mountain board (figure 3) is the most popular type of board and can be used on normal snow, on halfpipes, for catching air, but it is best used on powder snow [6]. Freeride boards are the best choice for beginners because they are not too stiff or flexible, making them stable and maneuverable [1]. Also, this board is able to make quick turns and is all right for doing freestyle moves due to its ends being slightly turned up [1].

Figure 3: Freeride/all mountain board [6]

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The freestyle/technical boards (figure 4) are wider, more stable, shorter, lighter, and more flexible [1]. These boards are built for doing tricks such as jumps, spins, grabs, and rails. They are not made for making quick or tight turns [1]. Snowparks are usually where one can observe the riders with these boards. These boards are also suggested for beginners.

Figure 4: Freestyle/technical board [6]

The Carving/Alpine boards (figure 5) are narrower, thicker, longer and stiffer than the other boards [7]. These boards are great for high speeds, sharp turns and thus racing. These boards have their bindings pointed slightly towards the nose for easier turns. These boards are not suggested for beginners due to their lack of stability [1].

Figure 5: Carving/alpine board [6]

SNOW

When snowboarding the quality of the snow is very important. First off, kinetic energy is generated and released as heat when the board is gliding over the snow [8]. This creates a very thin layer of water, “more than a hundred times thinner than a dollar bill” [8]. Thus a hydroplane effect is created, making the board slide and not stick [8].

When the temperature rises and the snow becomes somewhat liquidated, known as wet snow, the snowboard’s ability to slide reduces, creating a decrease in speed [8]. This is because the layer of water beneath the snow increases, creating cohesion, having the same molecules stick to one another, and adhesion, were the different molecules are attracted to one another [8].

At nighttime, once the temperatures have decreased, the wet snow turns into a dense icy surface[8]. This makes it harder for snowboarders to ride because it is more slippery [8]. Also, the surface is not always smooth. There are points were the wet snow freezes somewhat rocky

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Ceren YuksekWRIT 340 Illumin Assignment

because of it not having a smooth surface beforehand; this results in an uncomfortable ride for the snowboarder.

THE PHYSICS

BASICS

The most important aspect in learning snowboarding is keeping balance; keeping one’s center of gravity over the riding edge does this [9]. One must simply keep their legs bent and their body upright (not bending the upper body). Another important aspect in snowboarding is that it is based on converting potential energy to kinetic energy to gain speed. The higher the hill that a snowboarder is going down, the faster he/she will go [8].

When a snowboarder shifts his/her weight forward (downhill), he/she increases the speed; whereas, when a snowboarder shifts his/her weight backward, he/she decreases the speed.As seen in surfing and skateboarding, snowboarders shift their weights from heel to toe when they want to make turns, when they want to change direction, or when they want to stop. For example, if a snowboarder is goofy (right foot front) and wants to turn right, he/she will shift their weight to their heels and slightly twist their body clockwise. As for stopping, snowboarders must dig their heels or toes into the snow depending on which way they are facing (upwards/downwards) [9]. They do this in such a way that the edge of the board that’s closest to the top of the mountain is digging in to the snow, and thus tilting the base, which drags the snow.

Boarders can decrease their speed with two types of turns: carving, and/or skidding, creating frictional resistance [5]. These turns are done in zigzag patterns (figure 6). Skidding, a technique that is usually used by amateur riders, is when the snowboard is tilted and the base of the board is still somewhat in contact with the snow [5]. This turn requires less balance. On the other hand, a carved turn, requiring more balance and used at higher speeds, is achieved when a board is tilted and its base is not touching the snow (where the edge of the board leaves a linear track) [5].

Figure 6: Zigzag pattern in snow [5]

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Half-pipe

A half-pipe is a man made U-shaped channel made in the snow for snowboarders to use for jumps and tricks [1]. When going into the halfpipe one goes down the hill and uses their speed to reach the highest point of the halfpipe. From there a snowboarder rides down from one side of the halfpipes ‘U’ and up the other side [8]. The snowboarder’s momentum carries the rider up the wall of the other side of the halfpipe. However, when going up the wall, gravity slows them down, which means a rider has to have enough speed to minimize the effect of gravity.

As displayed by Paul Doherty, a physicist funded by the National Science Association, the halfpipe is a great example of dynamic science [10]. Snowboarders feel the gravity giving them speed as they are going down one side of the halfpipe, and it’s gravity, as well, that slows them when they go up the other side of the halfpipe [10]. “At the same time they are being pushed against the sides of the half pipe by the contact forces from the surface of the snow” [10].Snowboarders gain speed as they push back against these forces, and thus they get air. When a half pipe’s sides are taller, snowboarders go faster. As a snowboarder goes up the wall of a half pipe his/her kinetic energy, speed, decreases (due to gravity) and turns into potential energy: the energy that gives matter the potential to move [8]. “When they are at the highest point of their jump they have the most potential energy” [10]. As a snowboarder goes down the ramp his/her potential energy becomes kinetic energy [8]. The higher speed of a snowboarder equals an increase in the amplitude of a jump.

Halpipes are great for getting air and doing jumps and tricks such as 360s, grabs, and more. A very important technique to know while trying to do tricks on a half-pipe is the use of pumping to increase speed and angular velocity [8]. While pumping, a snowboarder must crouch down at the flat section of the half-pipe, he/she must then raise their body and arms as they go up the curve [8]. This moves the snowboarder’s “center of gravity closer to the center of his curving path in the pipe increasing his overall velocity” [8] making the snowboarder ready for tricks.Last but not least, the take off timing, plays a huge part in achieving a trick. If one takes off too early or too late it would affect their amplitude and landing [8].

Torque

Torque is the force that makes an object rotate [8]. This force is fundamental for performing spins and tricks. Snowboarders create torque by rotating their torsos right before they launch offa jump or half-pipe [8]. This helps them rotate around their y-axis, making them spin [8]. As shown in figure 7, “To spin faster x-games competitors maximize their torque with their upper bodies by winding up and twisting in the opposite direction of the intended spin. All things being equal this effectively doubles the amount of torque generated. Enabling competitors to launch spinning at angular velocities of up to 600º per second” [8]. Also, when trying to perform a flip (rotate around horizontal axis), instead of twisting their torso snowboarders extend their legs at takeoff [8].

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Ceren YuksekWRIT 340 Illumin Assignment

Figure 7: Example of Torque, as a rider twists his torso counter-clockwise [8]

Double Cork

The double cork is a one of the harder tricks in snowboarding and it is performed in about 1.8 seconds [11]. In this trick a snowboarder performs a rotation in the air that resembles the double helix in our DNA [11]. Snowboarders must use torque for this trick. Shaun White, an Olympic gold medalist for snowboarding, was recorded while doing this trick and he had an angular velocity of 540º per second after he launched [11]. During 44% of his time in the air, Shaun has to be looking up, increasing the risk of this trick [11]. The margin of error in a double cork is ±2 feet, which could result in a very risky landing [11]. Lastly, while landing this trick Shaun can experience an impact of 1100 pounds of force [11]. Many factors of physics are involved in this trick including torque, velocity, the angle that he launches at, his amplitude and more.

CONCLUSION

Science has advanced this sport to the way it is today. With the changing technologies of the board, the findings on how the condition of the snow affects the ride, and the physics in the old and new tricks, snowboarding should be a sport that is researched more often. Snowboarding, now an Olympic sport has come a long way since the 1965 Snurfboard [1], and it will go further, and improve more, like it has with the snow kite boarding, and other new technologies. It is a sport to keep an eye out for those who seek adrenaline.

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Ceren YuksekWRIT 340 Illumin Assignment

REFERENCES:[1] S. Watson. How Snowboarding Works [online]. Available: http://adventure.howstuffworks.com/outdoor-activities/snow-sports/snowboarding.htm[2] Snowboard Equipment and History – History [online]. Available: http://www.olympic.org/snowboard-equipment-and-history?tab=history[3] Vancouver 2010 – Snowboarding [online]. Available: http://espn.go.com/olympics/winter/2010/sports/_/name/sb/snowboarding[4] Snowboard Science [online]. Available: http://www.snowboardreview. com/snowboard_guide/science/[5] The Physics of Snowboarding [online]. Available: http://www.real-world-physicsproblems. com/physics-of-snowboarding.html[6] Snowboard Types – Different Types of Snowboard [online]. Available:http://www.abc- ofsnowboarding.com/snowboards/types-of-snowboards.asp[7] Snowboard Equipment and History – Equipment [online]. Available: http://www.olympic.org/snowboard-equipment-and-history?tab=equipment[8] Snowboarding Science: The Physics of the Halfpipe [online]. Available: http://www.planetscience.com/categories/over-11s/physics-is-fun!/2012/11/snowboarding- physics-at-the-winter-xgames.aspx[9] P. McCulloch. What is the physics involved in snowboarding? [online]. Available: http://www.physlink.com/education/askexperts/ae447.cfm[10] Science of the Olympic Winter Games: Science of Snowboarding [online]. Available: http://www.nsf.gov/news/special_reports/olympics/snowboarding.jsp[11] (2010, Jan 28) Sport Science: Spin Like Shaun White [online]. Available: http://espn.go.com/high-school/video/clip?id=6610485

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