Tethercars are kind of a cross between a nitro RC car and a control line airplane, in case you’re not familiar. (Not many people are, after all.) They’re specialized high-speed model cars with a small aircraft engine that drive in a circle on a specialized course, by means of being controlled with a steel cable—there’s no steering or throttle, just turn it on and hold on tight—and it turns out despite their simplicity, they can get moving.
The video above shows a tethercar time trial. The car is pushed to start, and the “driver”, who stands in the middle of the course, pulls it around the track via a steel cable. When the car is going fast enough, the “driver” releases the tow rope and gets out of the way, and the car keeps the cable off the ground through sheer momentum. Once the car performs its top speed run, and the time trial is over, the fuel supply is shut off by hitting the fuel cut switch located on the outside of the car with a broom.
Of course, in the time trial above, the car hits an absolutely absurd 205 mph, which makes the simple-sounding hobby take on another level of complexity. That’s not a scale speed, that is a bonafide 205-mph toy being held onto by a guy with a steel rope, followed by him jumping onto a small platform to get out of the way when it’s moving too fast to hold onto. This, somehow, isn’t even the fastest one out there; the current official record-holder, according to the American Miniature Racing Car Association, clocks in at a blistering 215.9 mph on the standard-size 70-foot-diameter cement circle track. These speeds are achieved thanks to highly aerodynamic designs that resemble full-size top-speed-run Bonneville race cars, combined with miniature gearboxes paired with extremely efficient 10cc engines that run on methyl alcohol fuel. Those engines can rev up to 30,000 rpm, which, combined with a 200+ mph Doppler effect, leads to the insane sound heard in videos of top-speed runs.
The hobby/racing/sport was once incredibly popular in the U.S. in the years after World War II, with over 400 tracks in the US at its peak of popularity. Today, there are only three courses left (in Illinois, Indiana, and California) and despite the introduction of electric tethercars that can pull speeds well over the 200 mph mark, without tracks, it’s a bit difficult to see a resurgence in popularity coming. Still, I can hope, because this is the kind of weird hobby I could totally get into.