We Still Don’t Know How Bicycles Work

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It’s easy to build a rocket. It’s not like it’s bicycle-science

Bicycles: We must thwart all attempts to study us. If the humans find out we're sentient they wont sit on our faces anymore.

I just taught my 2 kids to ride their bikes last weekend, it’s amazing to watch them find their balance and know once you find it, you will always have it.

I was around seven when my dad bought me a bicycle and attempted to teach me how to ride it. He spent hours and finally gave up in disgust. In ten minutes, without dad there, I figured it out and within an hour on my own, I was pretty good at it. How to ride a bicycle is difficult to explain to another person, they just have to figure it out because of being somewhat intuitive.

"Sure, it works in practice, but does it work in theory?"

"According to all known laws of engineering, there is no way a bicycle can remain upright. The bicycle does so anyway because it does not care."

One property that was not mentioned is the fact that the geometry of the front steering is arranged so that when the steering is turned, the center of gravity of the bicycle is raised. This effect will give a self-steering effect as the raised weight will try to go back to the minimum height when the steering is not turned. This is achieved by arranging for the castor angle to set its hinge line such that the hinge line projected line will project down to meet close to the point of contact of the wheel with the ground. There are other factors to consider. The turning of the steering will displace laterally the centre of gravity of the bicycle so that CG oscillates about the line on the ground joining the front and back wheels. It is this oscillation of the center of gravity of the bicycle about the line joining the point of ground contact of the front and back wheel. All this is related to a tight rope walker riding a bicycle on the rope handling his own weight shift or that of a pole. Rather than turning the steering wheel to change the center of gravity about the tight rope, all the driver does is change his weight above the tight rope laterally to the tight rope below him. Since the footprint below a bicycle is always a thin line then the center of gravity must always oscillate about the line. All one needs to do to check this is to keep the bicycle stationary and turn the wheel to the right or left and one can easily note that the center of gravity is changing. Also, the steering of a bicycle needs to be turned in the direction of the fall WHERE THE RATE OF CHANGE OF THE TURNING OF THE HANDLEBARS MUST BE FASTER THAN THE RATE OF FALL OF THE WEIGHT. I find it difficult to believe that the mathematicians of the earlier centuries could not see these three-dimensional mathematics. Note that the self-steering of a car is related to what was said above. The weight is lifted when the wheels are turned and when the steering wheel is free the weight of the car will drop down to the minimum height which is when the front wheels are pointing straight ahead. It is very interesting that the projected hinge line with the point of contact changes with the inflation of the tires and so one should keep the tires blown up at the right pressure, for there are situations when the steering is turned beyond an angle the steering becomes unstable and does not return to facing the front, When trying to understand the steering of a bicycle or a car, do all movements very slowly as there are at least three procedures going on at the same time. Note again the raising of the CG which this video did not mention. Note that the gyroscopic effect of the rotating wheels of the bike is minor and can be totally eliminated at the slow speed we normally ride. It is the shifting of the CG about the line of wheel contact with the ground and the rate at which the handle is turned with respect to the falling of the CG. so that the CG jumps over the line joining the contacts points with the ground of the front and back wheel.

“Mathematicians began to seriously investigate the mysterious physics of the bicycle’s remarkable stability.” Great sentence. Should be a rap.

"Bro, check out this thing I just invented." 'Wack. What do you call it?' "A bicycle." 'How does it work?' "... you know, I have no clue."

"and, of course, it's boring to write it up" Our bicycle understanding is being hindered by how boring it is.

Did a class project on bicycle stability in Mech. Engineering class--it's surprisingly complex and difficult tho I managed to understand and explain most of it. It was entirely optimized via trial and error and can't be improved on, it can only provide trade offs between, say quick handling and high speed stability. 5 or 6 geometric/mass factors involved.

I think a big part of why the mystery remains is that studying it is not worth economically, since bikes anyway work. This reminds me of the theory of planes, which was at least wrongly understood and explained in pilot schools during most years of airline companies. Also, makes me think of Swifts and the fact that they seem to sleep in the air, but we have no idea of details... who would invest in researching that? The story of Papadopoulos being late even when the matter was his passion, and in the end losing it all, truly hits home :D

In 2020 we will have flying cars 2021: We still don't know how bicycles work

“It just works”-Todd Howard

I used to work for Bicycling Magazine in the 1980's. I met of heard of at least half of those engineering types. I met one Crispin Miller, who knew (probably) all. As the low man on the totem pole, all this math boggled the mind. I learned to see geometric differences in bicycles at a glance. At this time, Mountain bikes were evolving from downhill coasters to all out performance bicycles that could handle everything Earth threw at them. The 80's were a remarkable time for the sport. As an elder, I still ride... not the 200-300 miles per week... but per year... it's a goal now. Loved this video. Will share with former coworkers.

Side note here, David Wilson was not the inventor of the Recumbent Bicycle, that was Charles Mochet in the 1930's. First his Velocars, then the first performance Vélo Couché. A Recumbent (Nazca Gaucho) and a Quest Velomobile are my normal bikes 😉 Taking the Gaucho to Zürich this week, cycling & camping to the Recumbent World Championships in Lustenau, Austria. All races under our own IHPVA & WHPVA organisations, because the UCI doesn't consider our vehicles legal... 😏

Every two wheeled vehicle (including bicycles, motorcycles, segways, ect) has it's own personal invisible gnome that runs beside it to hold it up.

After trying to distract myself from the fact that I've had three bicycles stolen from my shed today, the youtube algorithm puts this in my autoplaylist.

As someone who still can't ride a bike cause I could never understand how a bike stays upright, I approve of this video