Bikes are a fun and healthy way to get where you are going. While there are many different types of bikes available, they all work in a similar way and seem quite simple at first glance. With the right materials, anyone could make one that would work.
But, how do they work?
Oddly enough, we don’t actually know the physics of it all.
In fact, a team tried to figure it out and even published a paper on what they did, and we still don’t have a comprehensive understanding of how and why bikes move the way they do.
Fortunately, anyone who has learned to ride a bike does know what they react to and is therefore able to enjoy a nice ride down the road.
In the paper, the team wrote:
“The common view is that this self-steering is caused by gyroscopic precession of the front wheel, or by the wheel contact trailing like a caster behind the steer axis. We show that neither effect is necessary for self-stability. Using linearized stability calculations as a guide, we built a bicycle with extra counter-rotating wheels (canceling the wheel spin angular momentum) and with its front-wheel ground-contact forward of the steer axis (making the trailing distance negative). When laterally disturbed from rolling straight this bicycle automatically recovers to upright travel.”
Woah, they are taking this seriously.
One key example of this in action is the fact that when you turn on a bike, you first counterturn in the opposite direction a little bit. Most people don’t even realize that they do this, but without this action (or one of a few alternatives), every turn would land you on the ground.
So, the next time you take your bike out for a ride, try to think about just how complex the physics behind what you are doing really is. And see if you can figure out how it all works. Because if you can, you will be the first one.
You can see a video illustrating the types of tests done for the paper here:
I’ve never given it much thought.
If you think that’s impressive, check out this story about a “goldmine” of lithium that was found in the U.S. that could completely change the EV battery game.
