News

May 09, 2023

Why ball bearings are all around us

Ian Sullivan for the Deseret News I remember when I learned to ride a bicycle —

Ian Sullivan for the Deseret News

I remember when I learned to ride a bicycle — five years old, three-and-a-half-feet tall. At first the bike was heavy and awkward and I crashed into the asphalt more than once. But then I got it — how to balance and pedal and steer — and I was flying. I realized I had spent my life pretty much as a stationary object, but now I had wheels and my own velocity. I could turn in circles or go fast in a straight line. It felt like freedom. It felt like magic.

At that time I did not question how it could be that a five-year-old could zip around like a bird with very little effort or restraint. I took it for granted. Bicycles existed, therefore I would ride them. For fun. Because I could. When my bike broke down, anything other than a flat tire, I didn't know how to fix it. Eventually I’d get a new one. I was ignorant of the machine, the way the magic actually worked.

When I was 19, I moved away from home to go to college. I didn't have a car, so I needed a bike, and there was a bike shop across from campus. I went in and told the long-haired mechanic I wanted a bike that turns well at high speeds and doesn't break down. He brought out a Motobécane, red and black, made in France. I rode it and fell in love.

The mechanic, however, warned me about the bike breaking down. He said, "This is a good bike, with good components, but even the best bikes need to be maintained."

Bicycles, he told me, are the most efficient form of transportation, by far, because they are lightweight and they roll on ball bearings. All the moving parts — the wheels, the pedals and crank, the steering column — they all spin on ball bearings.

"You can't see them," he said. "They’re hidden inside — rings of steel balls spinning inside doughnut-shaped shells, or it's more like they’re sandwiched between two sides of a bagel."

He held his hands like he was holding a bagel together. "Too tight and the balls don't spin. Too loose and the balls wobble. But in between there's a magic spot where there's no friction."

He picked up a front wheel lying on the bench, told me to hold it by the axle — one hand on each side — and he gave it a spin.

He said, "A guy brought in this wheel because it was wobbling, because it had loose bearings."

The wheel in my hands felt like it was spinning on butter — silently, no vibrations — like it was never going to stop.

"I adjusted the bearings," he said. "Now it's good."

He told me the bearings in my bike were also good, for now, but eventually they’d all go out of alignment and need to be adjusted.

"It's just the way it is," he said, "So it's time you learn how to maintain your bearings."

I bought the bike and a bunch of tools, the ones he said I needed.

I don't remember how long it was after that, or why specifically I started taking the bike apart, but there came a moment when the bike was in pieces and I had a hundred small steel balls rolling around on my kitchen floor. I’d rendered a perfectly functioning machine into chaos, and I thought, "This may not end well."

It turns out ball bearings are all around us, inside all our wheels and motors. We don't see them in action because they’re hidden, enclosed by design. But they are here, inside our fans and vacuum cleaners and jet engines, as well as our bicycles, cars and trucks. They are literally how we roll. Without ball bearings, civilization as we know it would come to a loud, grinding halt. And yet we give them very little recognition or respect. We don't think about where they came from or how they got here. We don't know we’re dependent upon them.

There are many kinds of bearings. Some have balls or roller elements and some do not. The thing they all have in common is their function, which is to reduce friction. Today, this is what we need and want — less friction, in more ways than one — but for most of human history friction was not a problem, not something that needed to be reduced or overcome. Friction used to be a good thing. It's how we kept from slipping while walking. It's how we built our fires.

But then, about 10,000 years ago, people started moving large rocks across the ground to build sacred, megalithic monuments. We’re talking about rocks the size of elephants and whales, often transported many miles, to build structures that connected the earth to the sky, structures that had magical powers. This is when friction first became a problem, and it's how our dependence on bearings began.

They were Stone Age people, meaning they had only stone tools to work with. Horses were not yet domesticated. The huge boulders they moved and placed are still standing across Africa, Europe, Asia and islands in the Pacific Ocean. Nobody knows for sure why they did it because they didn't write things down. There was no written language back then. So we don't know for sure how they did it, either, but there seems to be only one possibility.

Think of Stonehenge, built 4,600 years ago on what is now the Salisbury Plain of England. The tall standing stones in the outer ring are 13 feet high and seven feet wide, four feet thick, each weighing up to 30 tons, and they come from a quarry 15 miles away.

Imagine we’re standing there in the quarry, 4,600 years ago, looking at one of the stones lying on the ground — 13 feet long, 30 tons — wondering how we’re going to move it even one foot, let alone 15 miles.

We have one basic problem — too much friction. Friction comes from surfaces sliding or rolling over each other — the more surface area coming into contact, the more friction is created. If our stone were shaped like a ball, it wouldn't have much surface area touching the ground and we could roll it, but instead of a ball, we have long slab. To slide it across the ground seems impossible.

Our only hope is to lower the amount of surface area coming into contact between the rock and the ground. You may have already come up with the answer — we use smooth logs as roller pins under the rock. We chop down some trees with our stone axes and smooth out the trunks and we put them under the rock, one after another. The rock doesn't touch the ground, it rides on the rolling logs — a huge reduction in friction.

This is how we think they did it. We don't know for sure, but the only other answers are by magic or aliens.

These were the first bearings, the first step in overcoming the forces of friction. We now call them roller bearings and we still use them for conveyor belts.

The second big innovation in reducing friction was the invention of the wheel — or I should say the invention of the wheel and axle because they always go together. This place, where the wheel spins around the axle, that was the new bearing. We now call it a plain bearing.

For thousands of years, the methods and practice of building wheels remained essentially the same. All this changed in 1869 when a French bicycle mechanic named Jules Suriray designed and built ball bearings for a bicycle wheel. The bicycle was a great leap forward in the evolution of bearings and the reduction of friction.

It started with the running machine, invented in 1817. It was like a bicycle, but it had no pedals. The frame was wood, the wheels were wood with plain bearings. To make it go forward or backward you had to walk or run your feet along the ground. The French called it the velocipede. By 1860 velocipedes in Paris had rather beautiful lightweight steel alloy frames. Pedals were added over the next few years, and the bicycle was born. The early bikes had big front wheels because that way they’d go farther and faster for every turn of the pedals.

By 1869, there were young men racing bicycles all around Paris. People called the bikes bone-shakers for all the banging and bouncing over cobblestone roads. These banging and bouncing forces went first to the plain bearing in the front wheel and then through the steel frame to the bones of the rider.

Bearings wear out, just like lower vertebrae. The moving parts need to function as a unit — everything staying the right shape and size, in alignment — while moving across the ground and being subjected to the forces of gravity and lateral accelerations. You can start off with everything working together really well, but eventually friction is going to create heat which causes swelling which causes more friction … and the unit is going to fall apart, especially if there's banging and bouncing involved.

We know Suriray was a blacksmith/bicycle mechanic in Paris. We know he had a shop near the Place de la République. But, unfortunately, very little is known about his personal history or how he came up with his ball bearing design.

I assume, or I imagine, that young men around Paris brought Suriray their broken bicycles and asked him to fix them so they would go even faster. They wanted a competitive edge. Suriray looked at the bicycles and realized their front wheel bearings were wearing out from friction and abuse. If he could reduce the friction, the bike would go faster and last longer.

We know there was a big race coming up — November 7, 1869 — the first long-distance bicycle race across the countryside, Paris to Rouen, 80 miles. Suriray did not invent the ball bearing, he was just the first person to build a ball bearing that actually worked for a wheel and axle. He hand-filed the steel balls and then used a lathe to make two round half shells, and then he figured out how to hold them in place — not too tight, not too loose — so the balls spun freely between the axle and the wheel. His design was simple, and it worked very well. It's basically the same design we use today. It must have felt really good when he gave the wheel a spin. It may have felt like magic.

One hundred and twenty riders showed up at the Arc de Triomphe for the start of the race. The course followed bumpy country roads with uphill sections where the bikes had to be pushed. James Moore, a 20-year-old Englishman riding Suriray's bicycle, finished first, 15 minutes ahead of the second and third riders. Moore became famous and Suriray went into business making bicycle wheels with ball bearings.

Then, in 1870, the Franco-Prussian war began and Paris became a war zone. Nobody there was interested in bicycles anymore.

Bicycle manufacturing moved to Germany, England and the United States. Ball bearings became standard parts but making them was difficult, especially the steel balls, as they were shaped and filed by hand, one at a time. Then, in 1883, Friedrich Fischer, a German bicycle manufacturer, invented the ball grinding machine that could produce large numbers of steel balls with fine precision, varying no more than two one-hundredths of a millimeter.

By 1890, bicycles looked and handled pretty much like they do today. The front and back wheels were the same size and they had inflatable rubber tires. The pedals were in the middle of the frame with a chain to the back wheel, and all moving parts (except the brakes) turned on ball bearings. They called it the safety bicycle because it was a lot safer and easier to ride than the bone-shaker.

By the mid-1890s a bicycle craze was sweeping across Europe and the United States. There were hundreds of bicycle manufacturers and millions of people riding. Bicycles gave people a new sense of freedom, especially women.

Women who rode bicycles started demanding equal rights, like the right to vote. You might say ball bearings went to their heads — they wanted to be free, without friction, in all parts of their lives, not just when they were on a bicycle.

All this changed, however, at the turn of the century when mass production of affordable automobiles put men back in the driver's seat.

Ball bearings were used in automobiles, and then in airplanes, as well as in electric generators and electric motors. Without ball bearings to reduce friction, the spinning parts of these new machines would have heated up and seized together.

In this way ball bearings became essential in our culture — like water is essential in our bodies. An illustration of this would be the bombing of Schweinfurt during the Second World War. At that time, 1943, the city of Schweinfurt produced approximately 50 percent of the ball bearings spinning inside the Third Reich's war machine. The strategy, therefore, was to cripple the war machine by bombing the ball bearing factories.

On the morning of August 17, 1943, 230 American B-17 bombers took off from England, headed across the Channel toward Schweinfurt, Germany. The bombers flew in a formation that stretched for 20 miles, blanketing the sky. Once over the continent, they were intercepted by German Messerschmitt fighter planes that began shooting them down. All the planes had ball bearings surrounding their propeller shafts. It was a battle of, by and for ball bearings.

The factories were hit but suffered only temporary damage, while the Americans lost about 20 percent of their planes and their crewmen — either killed or taken prisoner. Clearly, the bombing mission had not been a success. So the allied forces did it again, and again — 22 times in all. And yet the German war machine never suffered for ball bearings.

Today we have most excellent bearings that ride on roller pins and roller cones as well as balls. We even have bearings that ride on fluids and air. For instance, the disc in my laptop computer spins on an air bearing where no solid surfaces come into contact, reducing friction to almost nothing. Today, friction is no longer a problem to be solved.

Our problem now is we have too many wheels and motors spinning all around us. We have grown dependent upon them and the fossil fuels that keep them spinning — we need and want more and more and more and more, while glaciers recede and species go extinct.

What we really need now is a new kind of bearing, one that's purely conceptual, a bearing that could hold together two opposing thoughts or beliefs — like science and religion, or us and them — in a way they could move together without friction. Jesus and Buddha thought compassion could work like this, as a conceptual bearing, but compassion always seems to be in short supply, or not around when you need it.

It's been 46 years since I was in college staring at the steel balls scattered on my kitchen floor, and I must confess that I have yet to master the art of maintaining my bearings, of finding the perfect spot — not too tight, not too loose — but I’m working on it.

This story appears in the October issue of Deseret Magazine. Learn more about how to subscribe.