As part of a project funded by the NWOs Netherlands Technology Foundation (STW), researchers at Amsterdam Vrije Universiteit (VU) have demonstrated why the so-called klapskate produces better speedskating performance. The klapskate (The Dutch word klap which means to slap is accepted as a universal prefix: German: Klappschlittschuh; Japanese: klapskato) is constructed in such a way that the shoe part can hinge up away from the blade to free the heel.
It turns out that the superiority of the klapskate is not so much because it allows the skater to extend his ankle joint at the end of the push-off phase but because of the location of the pivot point around which the foot rotates. The klapskate was developed by researchers and instrument makers at the VU in 1985 and was used for the first time in competitive speed skating by the junior selection of the Dutch province of South Holland during the 1996/1997 racing season. Since then it has taken the international speedskating world by storm.
The Amsterdam researchers invited ten top speedskaters to take part in experiments wearing standard speedskates and klapskates. It turned out that there was a 12% increase in the external power generated by skaters when they wore klapskates, allowing them to go 5% faster. As far as friction with the ice was concerned, there was hardly any difference between standard skates and klapskates. Although the front point of a standard (unhinged) speedskate scratches across the ice at the end of the push-off phase, this does not in fact lead to any appreciable loss of power. The superiority of the klapskate, which prevents the tip of the base from scratching the ice, cannot therefore be due to a decrease in friction between the skate and the ice.
Analysis of experimental measurements showed that the increase in power delivered using klapskates is to be found in the location of the pivot point around which the foot rotates, namely the hinge under the ball of the foot. With standa
Contact: Michel Philippens
Netherlands Organization for Scientific Research