How A Century-Old Skate Design Completely Changed Modern Speed Skating

Equipment can be a funny thing in sports, as we've seen with the ongoing Under Armor race suit debacle. But that's nothing compared to what happened in 1996, when the International Skating Union allowed skaters to begin using clap skates (or slap skates, depending on who you ask) in competitions.

It was a massive decision, to hear some of the athletes tell it:

"Our sport has hardly changed in 80 years," said Chris Witty, the top American female sprinter. "In one year, we have had to go from traditional skates to these machines on ice."

KC Boutiette, considered the top American male at the middle and longer distances, said his first reaction to the skates was dismay — and a desire to bring another innovation to the starting line. He wanted "to get a mountain bike, put studs on the tires and show up with that. I was bitter," he said.

"We want to keep the sport pure," [president of the U.S. speedskating association, Bill] Cushman said this month. "To our thinking, this is ... no different than doping ... [or] corking a baseball bat."

"This skate is an abomination," Carl Knight, the top American male sprinter, said through clenched teeth as he stared off into the horizon. "We must destroy it...or it will destroy us."

I made up that last one, but you get the idea: people were upset. It's hard to imagine Major League Baseball idly standing by as players start using corked bats, or the NFL shrugging as quarterbacks begin using footballs containing combustion engines to get a little extra distance on their throws. For a closer comparison, Olympic swimming squashed supercharged racing suits. But tennis and golf have changed dramatically with the advent of newer technologies, and that's what ended up happening for speed skating.

This is what haunted the skaters' dreams:

How A Century-Old Skate Design Completely Changed Modern Speed Skating

The obvious difference from the skates you used to rent at birthday parties (or were born wearing, if you are Canadian) is that the skate blade isn't in a fixed position, relative to the shoe portion. Instead, there's a hinge near the front part of the skate, on which the blade part can rotate, independently of the shoe portion. The back end of the blade isn't attached to the skate at all.

Before we get to the exact advantages this unholy device bestowed on lucky skaters, let's look at the inventions underlying it. Now, the clap skate seemed to take the skating world by storm around 1996-1997, so it's a safe bet that it wasn't invented much earlier tha—

Ice skate with flat vertical rotatable foot plate (German Patent Publication DE78733, 1894)

How A Century-Old Skate Design Completely Changed Modern Speed Skating

—or it was first patented in 1894, in Germany, by one Karl Hannes. Nevermind. Here's the entirety of the text of that patent, loosely translated:

The reason for the invention of these ice skates is to allow a simple method of free movement of the feet during both sightseeing as well as stunt skating and other possible means of travel.

Interestingly, there was no mention of the benefit of increased speed at all; the new skate was just supposed to improve tourism, figure skating, and... commuting? The inventor can be forgiven for not thinking about speed skating, though, as this invention predated the first Winter Olympics by 30 years.

The base piece "a" and the heel piece "b" are bound together; the blade "c" is hinged to these in such a way that the foot piece can swing up freely behind while skating. A spring "e" attached to the front of the base piece prevents the blade from dragging on the ground.

That seems helpful, or the blade would be flopping around like half of a walnut cracker while you were trying to pirouette your way up the frozen Rhine, or whatever people did in late 1800's Germany.

Using the screw "f", the blades can also be held in place so that it is possible to use them as normal ice skates.

And they were backwards compatible!

Patent requirements:

Ice skates whose foot piece is attached to the blade in such a way as to allow it to rotate and detach from behind.

Refreshingly concise. If you're wondering why nobody tried to use this sort of skate in competition for many, many years, one possible reason is the first page of the patent:

How A Century-Old Skate Design Completely Changed Modern Speed Skating

If you infringe a German patent, the Kaiser's Patent Office sends that scary eagle out to disembowel you. It's proven an extremely effective deterrent.

For whatever reason (but most likely fear of the eagle), this new type of skate didn't find its way into competition immediately. However, one Dutch speed-skating enthusiast/biomechanist would, decades later, complete independent research that would lead to its re-development.

Gerrit Jan van Ingen Schenau began studying the biomechanics of speed skating in 1978, and three years later published his findings as his doctoral thesis, "A power balance applied to speed-skating." He found what he believed to be a problem with either standard ice skates, the human body, or possibly both:

Based on research probing specific properties of the gliding technique (skaters push off while the skate continues to glide in forward/slightly sideways direction), it became clear that skaters suppress a powerful ankle extension in order to prevent the tip of the gliding skate from scratching through the ice, or even worse, that it might be pushed into the ice in such a way that one looses balance. Clearly, this suppression of a powerful ankle extension limits the ankle extensor's contribution to propulsion, when compared to the powerful ankle extensions as occur in running or jumping.

This sounds reasonable; imagine trying to run or jump while not being able to fully extend your ankles. "Cool!" you say. "I'm late-career Shaq! I say ridiculous things! Everybody loves me!" All of which is undeniably true, but the larger point is that your movement would be sub-optimal.

After publishing his thesis, van Ingen Schenau continued writing papers on skating biomechanics in the journal of a local (and apparently extremely serious) speed skating club. Besides looking more deeply into the problems created by a lack of full ankle extension (extrapolating his previous research on high jumpers), he also noted that with standard ice skates, the skate blade leaves the surface of the ice before the skater's knee is fully extended. This, too, was believed to prevent the knee from contributing as much as it could to the skater's power; obviously, once the blade is off the ice, it can't push against the ice. As a solution, van Ingen Schenau and others proposed the idea of a clap skate.

Klapschaats (Dutch Patent Application NL8500483, 1986)

How A Century-Old Skate Design Completely Changed Modern Speed Skating

It managed to combine the functionality of the earlier German invention with the aesthetic grace of a Slinky. Instead of having the heel portion completely unattached, there's a three-fold hinge portion, with some tension pulling it closed from a tiny spring which looks like it could go flying off at any second and frankly is making me uncomfortable looking at this graphic without goggles on. Can't they pinch the ends of the spring closed? Wouldn't that take, max, five seconds? Didn't the Dutch have some equivalent to OSHA back in the 1980's? So many unanswered questions. Once the skate is off the ground, the spring pulls on the hinge, which in turn pulls the blade back into the normal position, so that it's not flopping around loosely, and is ready for the next push.

Just like its predecessor, you could lock or unlock the back portion, so it could function as a normal skate. Based on the Google Translate version of this patent, the small piece labeled 7 catches hinge piece 6, which holds the hinge in this locked position until you lift piece 7 by pulling on drawstring 9, which seems like a dangerous and terrible idea if you're already speed skating (we'll come back to this), but we've already established that safety wasn't that big a concern for the Dutch in the mid '80's. Here's the skate in the open position:

How A Century-Old Skate Design Completely Changed Modern Speed Skating

Note that at the point 10 where the shoe portion is attached to the blade, there's no pivot point; the front of the shoe stays in a fixed position relative to the blade, unlike the older German version of this skate that we saw earlier.

Van Ingen Schenau then spoke with Viking, a major skate company, who encouraged him and his co-inventors to apply for a European patent. When they did, they found that their idea for the skate had already been preempted by—you guessed it!—Karl Hannes, in Germany, in 1894 (plus several other people). Even though this meant that they couldn't get a patent, they kept working on the concept.

While it was clear that the clap skate was potentially revolutionary for the sport, it still took some time for it to catch on internationally. Van Ingen Schenau's research group in Amsterdam noted, back in the mid-1980's, that the skate hinges hardly opened during competition, indicating that skaters needed to get used to the technique, or the hinges needed fine-tuning. Another possibility was simply that any non-Dutch skaters were waiting to see if people's times did, in fact, improve before investing their own time into re-training themselves on the skates. In any event, the skates didn't find their way into top-level international speed skating until the 1996/1997 season.

As you could probably guess by the pearl-clutching statements of American speed skaters quoted above, the new clap skates had quite the impact. In the men's 1000m race, it had taken from 1979 to 1996 to cut two seconds off the world record. After the introduction of clap skates in 1996, skaters lopped another two seconds off the record within about two years. The women found similar success with the new skate; after 9 years in which nobody could break a 1000m record set in 1988 (by an East German, meaning there's a non-zero chance she had some chemical help, or implanted robotic quadriceps), the world record was broken 4 times between 1997 and 1999 (including twice by Chris Witty, one of the skaters quoted above bemoaning the new "machines on ice").

During the skating season including the 1998 Nagano Winter Olympics, in the ten major events (500m, 1000m, 1500m, 5000m, and 10,000m, for both men and women), nine saw world records broken. The tenth (the men's 500m) had it tied. During the season including the 1994 Lillehammer Olympics, with skaters using the fixed-blade skates, only five records were broken.

In the meantime, remember how the fact that the clap skate allowed for a fuller ankle extension was what created such a huge advantage? Yeah, not so much:

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.

Apparently, further research determined that the benefit comes from the fact that the pivot point of the clap skate isn't the toe, as in standard skates, but near the ball of the foot. Even if van Ingen Schenau and his cohorts stumbled upon this advantage by accident, and were nowhere near the first to do so, they were still the first ones to see its potential in speed skating and usher it onto the international stage. Interestingly, the current style of clap skate lacks the back three-fold hinge present in the skate that van Ingen Schenau first tried to patent; instead, the back part is completely detached, like in the original German patent.

How A Century-Old Skate Design Completely Changed Modern Speed Skating

If you look at the world records, you'll notice that the clap skate's effect on world records is much more pronounced in the longer distance events. While the physical advantages of the clap skate are clear, they don't help very much at the start of a race; in fact, skaters are better off with traditional skates:

Slips at the start of the sprint events (500 m and 1000 m) are more common with the clapskate than with the traditional skate. Once the heel of the boot lifts off the rear support of the blade, the skater is balancing over a single point (the hinge). If the push-off force is not directed exactly through the hinge and perpendicular to the ice blade, the blade will slide forward or rearward. This slip was most evident on the first push-off at the start.

To deal with this problem, Viking produced a prototype of a hybrid skate with a computer chip attached. It would hold the blade in a locked position for the starting portion of the race, and then unlock, turning the fixed-blade skate into a clap skate. The International Skating Union stepped in and banned that one before it made it into widespread use.