Foil tip speed

The tip of the fencing blade is believed to be the second fastest moving object in sport behind a marksman’s bullet.

No. I just don’t believe it.

Here’s a flick recorded on 240 frames per second. No one records tip speed in world cup fencing bouts, so we can’t say for certain that there isn’t someone who’s making faster blade movements, but I think it’s fairly indicative of the normal speed of flick.

Here’s the relevant 12 frames of the video. Each frame is 1/240th of a second, so they represent 0.05 seconds of time.

To be conservative I’m assuming that in the first frame the tip is curved backward and right above my hand.

I’m going to error on the side of faster results to get what I think is a fair upper bound. Generously, a foil, plus hand to just below the wrist is 110 cm. Over the course of 0.05s, the tip travels a quarter circle – so that’s (2*pi*r)/4 or (2 x 3.141 1.1m) / 4, or 1.73m, which we’ll round up to 1.8m. 1.8m / 0.05s is:

36 m/s – or 80mph

Using 1m instead of 1.1m for the radius, adding an extra frame, and using 1.73 instead of 1.8 we get – 28 m/s or 62 mph for a lower bound

Comparatively, when taking a proper wind up and swing in a completely non-fencing way, it looks like you can get much faster speeds – which is unsurprising really.

My upper bounds estimate on this is a 1.3 meter radius (generously going up to my elbow), over 10 frames – which gets us in the 49m/s or around 110mph at best (more likely less than that).

How does that compare to other sports?

This image was recently posted to /r/dataisbeautiful

Fastest balls in sport

This is well below even the top 10 sports listed on this chart. The fastest tennis serve is roughly 50% faster than my fastest crazy swing speed.

And that’s only 5th on the list (which conspicuously fails to list Racquetball which easily has speeds in excess of 150 mph).

But it’s not surprising really. In things like golf, or racquet sports – not only is the athlete training to use their whole body to put as much force into the swing as possible (which is pretty much the opposite of what we do in fencing), but also, the projectile comes off of the face of the stick/racquet/club significantly faster than the head is moving. You can see this in golf and badminton slow motion replays.