"Clap, clap." Strange sound echoes in the skating rink. The sounds come from the slap skates when the iron blade hits the skating boot sole.
In 1996, just before Nagano Winter Olympic Games, top skaters in the world started to use the slap skates and made the world records one after another. So the slap skates were called "magic boots". Why were the skaters so successful with the magic boots, the slap skates? Here we try to find the secret.
The photo above is Dr. Jos de Koning from the Netherlands, one of the scientists who improved the slap skate mechanism.
Traditional skating blade is firmly fixed to the boot sole.
However the slap skate mechanism allows the blade to leave off the heel when the skater kicks off the ice.
And while the boot stays in the air the spring pulls the blade back to the heel position again.
The mechanism of skating boot with a movable blade was invented in Germany more than one hundred years ago.
In 1984 the Dutch researchers and the skating equipment company started to cooperate and made the slap skate light and strong enough to be used in the competition.
The pictures compare the kicking force of the traditional skate (above) and the slap skate (below). Downward arrows show the magnitude of the force.
From the first picture (the leftmost) to the fourth, the kicking force is about the same. The fifth one ( the rightmost) still show a small arrow in the slap skate but no arrow in the traditional skate. The red area of the slap skate is greater than the blue area of the traditional one. The area shows the amount of the force given to the ice.
Thus the movable blade of the slap skate can give a larger amount of force and a greater velocity.
The figures compare the kicking distance of the traditional (above) and the slap (below) skates. Each arrow shows the distance between the right and left toes. The red arrows of the slap skate are longer than the blue arrows of the traditional one. The longer arrow means that the skater is traveling farther forward. The slap skate enables the skater to move forward easily by detaching the heel from the blade.
Compare two types of walking, for example; walking with your heels always on the floor and walking with your heels free from the floor. You can walk faster when your heels are free.
