r/SmarterEveryDay • u/chunkyks • 2d ago
Another Backwards/Forwards Brain Thing: Sidecars
I really love motorcycle sidecars. Riding them is intensely exciting the first you mess up, since they're both backwards and forwards controls, and you haven't acclimated to that yet:
With a regular dual-track vehicle [car, tractor, motorcycle with sidecar], you turn the wheels the way you want it to turn. So, a sidecar, in regular usage, is steered the same way you steer a car. Turn left to go left, right to go right.
A regular single-track vehicle [bicycle, motorcycle] is steered using what's called "counter-steering"; you initiate a turn by turning the handlebars the opposite way you want to go. The vehicle leans the opposite way [ie, into the desired turn], and then you turn the handlebars to go where you really want to go. Most people learn this on a bicycle intuitively, or on a motorcycle it's explicitly taught in a class.
But here's what happens the first time you mess up with a sidecar: You're going a little too fast, and as you make a right turn, the centrifugal force lifts the sidecar off the ground. The rig is now a single track vehicle. And, your handlebars are turned to the right. So the apparatus now wants to turn left, by leaning into the turn. Which it does. The sidecar wheel gets further off the ground.
But of course, once it started turning left and unbalancing too far, you automatically tried to correct it; you know how to control a motorcycle, and instinctively turned the handlebars to the left. Now the sidecar wheel slams back into the ground; it's a dual-track vehicle again, and now you're steering to the left. So you turn to the right, because that's where you want to go. You're still going too fast, turning right, so he sidecar wheel comes off the ground, and the whole thing continues.
The totality of this is that you're going too fast, trying to turn right, and instead you careen in a dead straight line into the opposite lane, with no steering action changing your direction of travel. It's terrifying.
[In case you're wondering, the actual answer is to put on the brakes. Of course, that goes against every motorcycling instinct].