Understanding the science behind skateboarding
01 February 2018
Chris Johnson, managing director of SMB Bearings, examines the science of skateboarding and how you can optimise your board.
Skateboarding was first developed in the 1950s in California and Hawaii by surfers who wanted something to do when the ocean waves were flat. Since then, the art of skateboarding has grown significantly and there are now over 12.5 million skateboarders worldwide.
The first mass produced skateboards were manufactured by a Los Angeles surf shop, whose owners made a deal with the Chicago Roller Skate Company to produce a set of wheels that were attached to square wooden boards. Since then, the popularity and science behind skateboarding has soared and now a surprising number of elements must come together seamlessly to create a safe, smooth and speedy ride.
During the late 1970s, skateboard manufacturers began to experiment with board materials including composites and metals like fibreglass and aluminium. However, no material compared to the flexibility of maple plywood and the material increased in popularity. Modern skateboards are still often made from maple plywood, though they are now usually made from seven pieces of maple pressed together using aluminium, metal or concrete glues.
The boards are pressed to around 300 psi and then cured and curved over multiple days. They are then cut into the final shape using computer numerical control (CNC) machines or hand routers, after which the edges are trimmed and any design or paintwork is applied.
Tim Piumarta, one of the most influential skateboard designers, says that, “With all the alternative materials we’ve tried, from epoxy and fibreglass to carbon loaded thermoplastic nylon, nothing has the combination of toughness, elasticity, feel and response of laminated sugar maple board.”
Keep it rolling
Early skateboards were not only made from unsuitable materials, they also used wheel components that were far from ideal. The first skateboard wheels, made by Frank Nasworthy out of urethane in the early 1970s, revolutionised skateboarding.
When a skateboarder is rolling along the pavement or skatepark, the urethane wheels are slightly flattened by the weight of the skater, also known as deformation. Urethane is resilient and returns to its round shape quickly, pressing out against the ground before the wheel loses contact.
Many may think that a wheel that didn’t deform would be more suited, however a wheel made of hardened material would press onto the pavement, causing it to lose energy and speed.
Bearings for longevity and speed
While urethane wheels were ideal for skateboarding when they were first developed, they had one major flaw. The bearings used in the wheels were exposed and easily became contaminated by sand and grit from the road. As a result, the wheels couldn’t roll smoothly and the bearings wore out quickly.
The Road Rider wheel, developed in 1975, put sealed bearings into each side of the wheel, which meant that wheels lasted longer and could go faster than ever before. Combined with the urethane wheel, skateboarders would now experience a smooth and stable ride.
Today, things like precision grade lubrication and materials should be considered when selecting the right skate bearing. Custom designed skate bearings, like those provided by SMB Bearings, have been designed to specific criteria to satisfy even the most demanding requirements.
For instance, the balls in SMB Bearings' skate bearings come in either steel or silicon nitride (ceramic). Ceramic bearings are much lighter and harder wearing, meaning they are quieter and provide a longer bearing life. However, they do not flex in the same way that steel balls do, meaning that, under impact from jumps and tricks, the ceramic balls are more likely to cause indentations on the bearing raceway, making them rough and noisy.
Since the revolutionary developments in the 1970s, little has changed with the physical structure of a skateboard, however, the sport has developed significantly. Skateboarders have pushed the boundaries of what they are capable of, become professional athletes and secured the sport's inclusion at the 2020 Olympic Games in Tokyo - it’s not just an activity for when the waves are flat anymore.
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