#ICYMI - Motorcycle Racing: Physics on 2-Wheels

In case you missed this episode on the Playing with Science channel… We kick it into top gear as hosts Gary O’Reilly and Chuck Nice explore the physics of motorcycle racing, riding, and assembly alongside adventure journalist Jim Clash and physics professor and motorcycle aficionado Charles Falco. NOTE: StarTalk All-Access subscribers can watch or listen to this entire episode commercial-free here: https://www.startalkradio.net/all-access/motorcycle-racing-physics-on-2-wheels/ Photo Credit: SCrider (Flickr) via Wikimedia Commons.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:09Gary O'Reilly?

  I'm Gary O'Reilly.

• 0:10Chuck Nice?

  I'm Chuck Nice.

• 0:11Gary O'Reilly?

  And this is Playing with Science. This time we take to the track on two wheels.

• 0:17Chuck Nice?

  Yes.

• 0:17Gary O'Reilly?

  Yes, and as always, our need for speed will be equally matched by our need to know.

• 0:23Chuck Nice?

  Yeah, yeah, and our need to know is still our need for speed. And did you ever wonder how and why a motorcycle racer goes through a bend almost horizontal? Well, the man with the answers is University of Arizona's Professor of Optical Sciences and Physics, as a well-known, passionate motorcycle collector and rider himself. We're talking about Professor Charles Falco. He'll be joining us.

• 0:45Gary O'Reilly?

  Very interesting man indeed. And back for another spin around the Playing with Science track. And joining us first in the studio is our very good friend and doer of daring deeds. Yes, the adventure journalist, Jim Clash. Jim, welcome back.

• 0:58Speaker 02

  Jesus, thanks, guys. I feel like I'm becoming a regular here.

• 1:02Chuck Nice?

  Yeah, man, we love having you here.

• 1:04Gary O'Reilly?

  Don't worry, you get child's rent before you leave.

• 1:06Speaker 02

  I'm sure.

• 1:06Chuck Nice?

  And all the stuff that we only think about doing.

• 1:09Gary O'Reilly?

  Oh, yeah, it's a boy's own story. I am very, very envious. Now, because this is two wheels, and you're more in tune with four, but you have been on a motorbike at 140 miles per hour.

• 1:24Chuck Nice?

  Which is crazy.

• 1:25Gary O'Reilly?

  Says him.

• 1:29Speaker 02

  Who's been a lot faster on a motorbike.

• 1:31Chuck Nice?

  Not that much faster, but I've done, I've done, I've done pretty fast.

• 1:34Gary O'Reilly?

  So this was the superbike pro racer, Chris Olrich, and he went to Sturgis Motorcycle Rally last summer in Dakota. So are you kind of finding your way towards the two-wheel sector of motorsport? Or are you just, hmm, what's this about?

• 1:50Speaker 02

  You know, when I was a kid, my mom always said, "You can't drive a motorcycle, you'll lose a limb." And I was in the very formative years, so I never got on with motorcycles. I'm afraid of them. However, I couldn't pass up the chance when Chris Olrich offered me a chance to get on the back of his motorcycle at 140 miles an hour. He also took me through a road course where we were literally, you know, almost, you know, where your knees are dragging and that sort of thing, so.

• 2:17Gary O'Reilly?

  Was that the first time you'd ever done that?

• 2:19Speaker 02

  Yes, that's the first time I've ever been on a motorcycle.

• 2:21Chuck Nice?

  Really?

• 2:21Gary O'Reilly?

  How, how did that work between your ears? That space between your ears when you're thinking, "Oh, my word, I'm about to kiss..." The black stuff here. This is asphalt, this is tarmac, this is not good.

• 2:33Speaker 02

  Again, I had faith in Chris. I watched him do it with someone else before I did it. And I thought, this is my story. I put myself into that role of the journalist and I have to write about this. So rather than being fearful, I was thinking, okay, what is this sensation like? How am I going to write about it? And, you know, the fear kind of went away.

• 2:53Gary O'Reilly?

  So do you start this when you're writing with just, "Ohhhhh".

• 2:58Speaker 02

  I start with a...

• 2:58Gary O'Reilly?

  How do you pick? How do you, from a journalistic point of view, I'm interested now, approach that, looking back at your experience?

• 3:07Speaker 02

  Well, again, in a lot of my experiences, I have to be the active participant. I have to drive the car or ski to the South Pole or whatever it is. In this experience, I was just riding on the back of a motorcycle.

• 3:21Chuck Nice?

  By the way, it's also active in itself.

• 3:24Speaker 02

  Well, yeah, you have to move.

• 3:26Gary O'Reilly?

  Because if you don't engage with the process, you are fighting against...

• 3:29Speaker 02

  Exactly, exactly.

• 3:30Chuck Nice?

  Exactly. So even your passenger, by the way, can make a ride, you know, very dangerous. If you have the wrong passenger on the back of your bike, they are putting your life in jeopardy, you know.

• 3:44Speaker 02

  Yeah, they talked to me a little bit before I got on. But, yeah, I mean, I was a passenger. Now, I did go to Sturgis, which is where they have the big motorcycle rally every year in South Dakota.

• 3:53Chuck Nice?

  Lot of hogs in Sturgis.

• 3:55Speaker 02

  It was amazing, the number of different people there. There was a lady who was in her 90s who still rode her motorcycle to Sturgis from New Jersey. What's his name from the Doobie Brothers was there, he's a motorcycle guy. Pat Morris or Pat somebody.

• 4:14Speaker 02

  Tom Behringer was there from Platoon, he's a motorcycle guy. I mean, it was fascinating. They all wanted me to get a tattoo. They wanted to get the New York guy drunk and get a tattoo, but I didn't do it.

• 4:26Chuck Nice?

  Yeah, good for you.

• 4:28Gary O'Reilly?

  Okay, you've heard of the Isle of Man TT motorcycle festival, it's over a period of a week. Yeah, I think if you just heard Chuck say, "It's amazing", if you imagine, there's a whole load of public roads and therefore this is sort of quintessential village hill, slightly mountainous area on the Isle of Man, which is between Ireland and the west coast of England. It's a peculiar little place, yet they open it up.

• 4:55Gary O'Reilly?

  I think it was Frank Lids from Sports Illustrated back in two thousand and three, two thousand and four, said, um, it is thirty eight miles of terror, this one course, and that it is a test of nerve and speed and possibly the most dangerous sporting event in the world.

• 5:16Chuck Nice?

  Wow, I gotta tell you, I, I, I've never been to the Isle of Man, but I've watched it on television.

• 5:22Gary O'Reilly?

  Neither have I.

• 5:23Chuck Nice?

  NBC used to, it always comes on on a Saturday afternoon, and I love it. What gets me about the whole race is on the, in the professional side, is that the spectators are standing right on the course, which is dangerous in and of itself.

• 5:41Gary O'Reilly?

  It's like the Tour de France, where you see them line down the street.

• 5:43Chuck Nice?

  Exactly.

• 5:44Gary O'Reilly?

  Only you're gonna be hit by a bicycle, rather than a, a thousand cc superbike.

• 5:50Speaker 02

  And I'm sure, and I'm sure they have accidents with the spectators.

• 5:54Chuck Nice?

  Oh, for sure, they do.

• 5:55Gary O'Reilly?

  What I'm sensing here is a man who has made a reputation as an adventurer, an adventure journalist, took one look at the Isle of Man TT and went, no, thank you. A man who swam in the Arctic.

• 6:08Speaker 02

  At the North Pole.

• 6:09Gary O'Reilly?

  At the North Pole.

• 6:10Chuck Nice?

  Yeah.

• 6:11Gary O'Reilly?

  The man who's been at two hundred and fifty mile, three miles an hour, driving his, the car himself, looked at the TT and went, nope.

• 6:17Chuck Nice?

  Yeah, I mean, do you just, do you, you, so it's so funny that you, who've done all these, like, incredibly, I will say, adrenaline inducing activities, someone like you has never had, um, a desire to drive and ride motorcycles.

• 6:37Speaker 02

  I haven't, uh, I knew it was the cool thing to do when, back in high school and college, uh, but again, my mother, at that early age, telling me I'd lose a limb if I got on a motorcycle, uh, stayed with me. And, uh, again, I'm becoming a little more open to it now, not to this TT thing, that's nuts. But, but, but yeah, I was asking somebody the other day at the Explorers Club about how to get a license and what to do and what bikes are in and what bikes are out. He's got a Harley and, uh, so I won't say no forever, but I'll say no to that TT.

• 7:08Chuck Nice?

  Well, I'll say no to the TT. I mean, listen, I can't wait to get, I'm, I, I was saying before the show, uh, I'm definitely getting a bike again. I, like, once you do it, you, once you bike, you... For the rest of your life, you just.

• 7:20Gary O'Reilly?

  You've got to scratch that itch.

• 7:21Chuck Nice?

  Anytime I see somebody on a motorcycle, I think, God, what have I done?

• 7:25Gary O'Reilly?

  We're going to take our break.

• 7:27Chuck Nice?

  Yeah.

• 7:27Gary O'Reilly?

  We have got a unique character. Professor Charles Falco is not just a physicist. He is a motorcycle aficionado, a man passionate and a man responsible for being one of the curators of the art and science of motorcycles, which was one of Guggenheim's most popular ever exhibits. Stick around, we'll be back shortly.

• 7:55Gary O'Reilly?

  Welcome back to Playing with Science. Today, we're exploring motorcycle racing. And with us in the studio, we still have adventure journalist and our very good friend, Jim Clash. But joining us now to break down the physics is Professor Charles Falco. Welcome to Playing with Science, Professor.

• 8:11Speaker 03

  Well, thank you for having me.

• 8:12Gary O'Reilly?

  Let's just give you a proper introduction here. You are the Chair of Condensed Matter Physics, Professor of Optical Sciences and Professor of Physics at the University of Arizona, expert on the magnetic and optical properties of thin film materials. But the reason why you're really here, sir, is you are a motorcycle aficionado, a man that owns probably more than 15 bikes and at one point was part of the curating team for the Guggenheim Museum's exhibition of Art and Science of Motorcycles. Have I left anything out?

• 8:47Speaker 03

  No, that's, you've got everything.

• 8:51Gary O'Reilly?

  I'm pleased because that is a serious role of honour. So we are thrilled that you're on board.

• 8:57Chuck Nice?

  Where'd this start for you?

• 8:59Gary O'Reilly?

  Yes.

• 8:59Chuck Nice?

  Where'd your love of motorcycles come from?

• 9:03Speaker 03

  When I was eight years old, somebody gave a ride across Des Moines, Iowa on the back of a. Triumph Thunderbird motorcycle. The reason why I know that is that Triumph Thunderbird was the, actually the motorcycle that Marlon Brando had in The Wild One.

• 9:19Chuck Nice?

  Yeah.

• 9:21Speaker 03

  A modified, greatly modified version, won the world land speed record at Bonneville. And for two years, they had on the, the gas tank, uh, world's fastest motorcycle. And I was young enough that I thought I was on the world's fastest motorcycle. And I was hooked for life at that point.

• 9:38Gary O'Reilly?

  Oh, with eight years of age, you would. So, yeah.

• 9:40Chuck Nice?

  That's cool. So, maybe you know this because you're a historian as well. Uh, so you said that that modified version became the world's fastest motorcycle at Bonneville. Uh, Triumph also has a motorcycle called Bonneville. Is, is that because of that time trial success?

• 10:01Speaker 03

  Exactly.

• 10:01Chuck Nice?

  Oh, cool.

• 10:02Speaker 03

  It won the, uh, it set the world land speed record in 1956, I believe. And so, for the next two years, before they introduced the model of Bonneville, the Triumph Thunderbird had the decal on it that said world's fastest motorcycle.

• 10:17Chuck Nice?

  It's so cool to hear you say that. I'm getting so excited right now.

• 10:20Gary O'Reilly?

  You're gonna go and buy yourself?

• 10:21Chuck Nice?

  Well, no, that's gonna be my next bike, by the way, is a Triumph Bonneville. I'm just letting everybody know right now. That's, that's, you know. Mm-hmm. Yes. Red tank with the, what's that?

• 10:31Speaker 03

  You could do far worse.

• 10:32Chuck Nice?

  Thank you, sir.

• 10:33Gary O'Reilly?

  As a Brit, I would endorse the buying of a Triumph, of course. We've, we've sort of documented your, the genesis of your passion for motorcycles. Um, being a physicist, has it been a help or a hindrance being able to understand fully all of the science involved in getting the best out of your motorcycles?

• 10:55Speaker 03

  I would say, um, not necessarily the physics of the motorcycle, but the mechanics of the motorcycle has been intrinsic to all my work, my scientific work, my, as an experimental scientist. I think in terms of, um, I have instruments that we've built that are, at least in my brain, if no place else, based on what I know about, um, motorcycle mechanics.

• 11:20Gary O'Reilly?

  Wow. So, how, how interesting that you've approached the whole realm of your optical science through the lens of a, pun intended, a motorcycle.

• 11:31Speaker 03

  In fact, I mean, there's only three things that I'm interested in professionally. Physics, motorcycles, and art, and they all interrelate for me.

• 11:41Chuck Nice?

  Really? So now, when you say art, because I can see physics and motorcycle, because the two are inexorably tied together. Everything from gyroscopes to laws of motion, you name it. It's, you know, a motorcycle is nothing more than a rolling physics class, as far as I'm concerned, but I'm interested to know where the art ties in.

• 12:05Speaker 03

  So if you look up the Hockney-Falco theses, David Hockney, arguably the world's most famous living artist, he and I, about, well, 15 years ago now, discovered that artists of the repute of Jan van Eyck or Bellini, Caravaggio, used lenses to project images 200 years before Galileo, before people even thought lenses could be used. And the reason why I was able to make those discoveries with David was I've been interested in art and photography since I was five years old or so.

• 12:44Speaker 03

  So those passions of my physics and optics came from my interest in motorcycles and photography.

• 12:53Chuck Nice?

  Wow. That's, I have to tell you, that is a fascinating journey in terms of coming to science through, you know, through your personal passions. I mean, there's so many, I'm always interested when you talk to science, how is it that they come to their love of their particular scientific discipline or their study? And, you know, every scientist has a story, and I have to tell you, yours may be the most interesting.

• 13:19Gary O'Reilly?

  Yeah, I did flag up at the top of the show that we would find you very interesting. Has the art of the motorcycle kind of evolved for you through engineering, through shapes, through?

• 13:32Speaker 03

  The interest with motorcycles, the interesting thing about them is, there's very little on a motorcycle, there's two wheels, an engine, a gas tank.

• 13:40Gary O'Reilly?

  Yeah.

• 13:41Speaker 03

  You would think that you don't have much choice as a designer, but you can have two motorcycles. That you could orally describe would sound identical. One would be incredibly ugly and the other is a beautiful work of art. And so the the fact that minor differences in how these components are laid out, minor differences in curves make all the difference in the world with the beauty of the machine. Some of it's aerodynamic, some of it is intrinsically dictated by the physics. But another way of looking at the art or the design of motorcycles, you can watch the design of motorcycles evolve throughout the 20th and 21st century

• 14:24Speaker 03

  by watching material science, materials physics evolve. That every time some material is developed, it's incorporated in motorcycles.

• 14:33Gary O'Reilly?

  Okay, so let's go to the the back end of the 20th century and move it forward to where we are now. What has really changed the game in terms of material engineering?

• 14:44Speaker 03

  Carbon fiber entered about that time. So and the ability to create complex shapes through computerized aided TIG welding, tungsten and earth gas welding. So you could take something that wasn't possible not many years before that. You could decide a wrought piece of aluminum was good for one function, cast aluminum for something else, welded box section of aluminum for something else. And you could combine them with tungsten earth gas welding and create a structure where every aspect of it is optimum for its particular purpose. That wasn't possible before.

• 15:26Chuck Nice?

  Wow, and you know what's funny? I just thought carbon fiber was used so that they could make motorcycles really expensive.

• 15:34Speaker 03

  That, that too.

• 15:35Chuck Nice?

  That too.

• 15:36Speaker 03

  And also, part of materials technology is the evolution of microprocessors. And so fly by wire, computer controlled emission controls on motorcycles are possible because of developments in microprocessor technology.

• 15:56Gary O'Reilly?

  Okay, let's let's bring Jim Clash in on this.

• 16:00Gary O'Reilly?

  The professor engaging with a classic Triumph bike from the 50s.

• 16:05Chuck Nice?

  Woo.

• 16:06Gary O'Reilly?

  No processors, no carbon fibers.

• 16:10Chuck Nice?

  And by the way, beautiful.

• 16:12Gary O'Reilly?

  Beauty is in the eye of the beholder.

• 16:14Chuck Nice?

  This is true, but not when we're talking about that particular bike.

• 16:16Gary O'Reilly?

  I'm not going to argue with you.

• 16:17Chuck Nice?

  Okay, thank you.

• 16:18Gary O'Reilly?

  And you're looking at the development, the evolution of that. Then you get to the emotive side of it. Do you, as an adventure journalist, look at it and say, I would rather have the mechanical tactile human contact? Or would you rather have something that was more computer generated?

• 16:38Speaker 02

  Honestly, as a person who does this, not on motorcycles but in race cars, I'd rather have the tactile connection with the bike.

• 16:47Gary O'Reilly?

  Yeah.

• 16:48Speaker 02

  I don't want everything to be motorized or computerized. Honestly, I think they could take racing right now. They could put cars out there, computerized. They could have the drivers sit in the stands and drive them, but nobody would want to do that. They'd never want to see that.

• 17:02Gary O'Reilly?

  Right.

• 17:02Speaker 02

  People want to see people driving cars. So again, you can take it to the extreme, but I'd much rather be able to drive the car.

• 17:08Chuck Nice?

  I think you're right, and I think it's because what we want to see is the melding of person and machine becoming one. That's the thing that's exciting. So you, as a person who has driven in race cars and gone to race car school, and you know that there's a certain, there's a certain kind of synergy that you must create for yourself with that car.

• 17:33Speaker 02

  They say that the butt, when you're in the car, that's what you feel when you're turning a corner or whatever, that's what your indicator is, and then your hands follow and your feet follow. So you've got to be one with the machine. I got to think that with a motorcycle, there are similar things.

• 17:47Chuck Nice?

  And that's what I was going to say to Charles, professor, doctor, is that I think you would agree that I don't think there's any greater human integration with the machine than a person on a motorcycle.

• 18:01Speaker 03

  So I agree with that completely. And the motorcycle has everything you need and nothing more. And a difference with a car, a place where you're integrated even more so than a car. I live in Arizona. And here, when you're in the desert in the summer, it can be 110 degrees. But at the top of a nearby mountain, it can be 70 degrees. If you're in a car, you get in the car, you turn on the air conditioning, and you get out of the car an hour later, and suddenly you're shocked by the temperature change. If you're on a motorcycle, you're not shocked at all because you feel every minor one-degree change in temperature as you go through a shadow. You feel it. You feel the engine vibrate. You feel the road.

• 18:42Speaker 03

  The suspension is much more in tune with the road than a typical car suspension, which is supposed to get rid of all the bumps. Motorcycles, you feel the bumps. And so it's been said that you like objects or you hate objects, depending upon how many senses they appeal to. Like, you could look at a car and go, "That's a beautiful car, but, you know, so what? It's an electric car, you can't hear it, it doesn't vibrate." It appeals to your sense of sight. On a motorcycle, it's your sense of sight, the sense of sound, the vibration, the sense of smell. Every one of your senses is engaged. So either you, if you like them, you like them a lot. If you hate them, you hate them a lot.

• 19:24Gary O'Reilly?

  I'm not a motorcyclist. A lot of reasons why that never happened in my life. With a rider, it seems that rider becomes an active part of the weight transference, and therefore, that must be, correct me if I'm wrong, the real feeling of enhanced connection to the bike.

• 19:43Speaker 03

  A motorcycle weighs, let's say, 400 pounds. And a rider with his leathers and helmet and the like may weigh, let's say, 200 pounds.

• 19:52Gary O'Reilly?

  Yeah.

• 19:52Speaker 03

  So that's a significant fraction of the overall weight. A third is the rider. In a car... The driver is a much smaller fraction of the overall weight. So if the driver leans to the left or leans to the right, the car really doesn't care much about that. Motorcycle cares a lot about that. So you feel it. And so as a rider, you have much more control and you're much more integrated with the motorcycle than any car driver is with the car.

• 20:23Chuck Nice?

  Cool. So listen, we have to take a break. And so if you can stick around, and Jim, you can stick around, we can get back and get into some of the physics of what you were just talking about, being integrated with this machine and how the machine responds to you and how you respond to the machine and the road. Is that cool?

• 20:42Gary O'Reilly?

  That's very cool. Gentlemen, please stick with us, and our audience, please stick with us. We can take that short break. More from Jim Clash, our very good friend Jim Clash, and of course, the great professor himself, Charles Falco, back after the break. Welcome back. I'm Gary O'Reilly. And I'm Chuck Nice. As he is. And this is Playing with Science, and it's the physics of motorcycling. Yes, the two wheels rather than the four. We have Professor Charles Falco with us. You're off again, aren't you? I am. You are. Silly. Right. Professor Charles Falco is with us, and of course, adventure journalist Jim Clash. Professor, we've just been in the break, the conversation's been like a beehive.

• 21:27Gary O'Reilly?

  Let's sort of drill down into the science of things. If Jim's on the back of Chris Ulrich's superbike, and he's leaning or not leaning, what in terms of physics and science is and is not taking place? Please.

• 21:41Chuck Nice?

  And what do you want from a rider on the back of a bike?

• 21:43Speaker 03

  So what you want, the person in the back, to not do anything. Because we've already discussed that the rider and the passenger make up a significant fraction of the overall weight. So if the passenger decides to, as you're partway through a curve, to help you out by leaning into the curve, suddenly the bike is leaning much more than you planned for. And on the other hand, if the rider decides, sorry, the passenger decides, I'm scared, I'm leaning way over, we're going to fall over, I would have sit upright. Again, it throws you way off. So you want the... The passenger just simply to sit upright with respect to the bike, not with respect to

• 22:28Speaker 03

  earth.

• 22:29Gary O'Reilly?

  Right.

• 22:30Speaker 03

  So in the, um, the, uh, worldview of sitting on the motorcycle, they're always sitting bolt upright.

• 22:37Gary O'Reilly?

  Okay, so if we take the single rider, particularly someone in the MotoGP, for instance, where the, the curves are tight and fast and it's banked, it's flat, it always looks as, you don't need to put your knee down and lean like that, that's just you showing off, but there is some valid science behind that, I'm sure.

• 22:54Speaker 03

  Absolutely. And, uh, in science, I mean, in physics, if a student, um, submits some, um, elementary quiz and they call something centrifugal force, centrifuge force, then they get graded off because there is no such thing as centrifugal force.

• 23:11Gary O'Reilly?

  You've failed.

• 23:12Speaker 03

  It's centripetal force, the force is inward. However, when you're on a motorcycle and you're going around a curve really fast, you would swear anything that the force is throwing you outwards, that the force is throwing toward the outside. So what you want to do is you need to balance that centrifugal force, which is pulling inward, with the force that's pushing you out. And the, the ideal way of doing that is if you were leaned over all the way, except you have no traction there, so you can't do that. So you do need to lean as far as you possibly can to lower the center of gravity and to balance the forces.

• 23:51Gary O'Reilly?

  Okay, because I'm the non-rider here, and countersteer, is that something that goes on in racing? So, and I've, I've, I can tell you the term, I haven't a clue really what it means, please open that box for me.

• 24:04Speaker 03

  Yeah, so actually, um, way back when I was in graduate school, I tried to make a, a, uh, Super 8 movie about countersteering.

• 24:11Gary O'Reilly?

  Ah.

• 24:12Speaker 03

  And where I was sitting, I had a friend following me, I was sitting on the back of somebody else's motorcycle, facing backwards, filming this, and the concept of countersteering is, counterintuitively, if you are going down the road and you want to turn left, you push on the left handlebar. It's as if you're turning the, the wheel to the right in order to turn left. That just doesn't seem right.

• 24:37Chuck Nice?

  Right.

• 24:37Speaker 03

  What is happening is because of the moment of inertia of this heavy mass of a spinning wheel, when you push that direction, it actually flops the bike over to the left. You want to go to the left? You're pushing in the left handlebar, which like I said, makes you think you're going to go to the right, but it flops the bike over to the left. And now, instead of riding on the center of the tire, you're on the edge of the tire where the circumference is less. So you turn to the left. And that's what countersteering is. And the thing is, it's so natural that many people who've been riding many years can't describe it. They have to think about it. They have to get on the motorcycle to do it. Because you just do it.

• 25:21Speaker 03

  You're not solving Newton's equations and deciding which way to push. That's in your neurons.

• 25:29Chuck Nice?

  Jim had something that she wanted to ask.

• 25:30Speaker 02

  Thank you, by the way, Professor.

• 25:32Chuck Nice?

  By the way, that was a great explanation of countersteer.

• 25:35Speaker 02

  My thought really was, when I was on the back of that motorcycle at 140 miles an hour, and that was on a straightaway. And then we went through the corners on a course at much slower speeds, but still pretty fast. I wasn't thinking about centrifugal force. I wasn't thinking about moving anywhere on the bike.

• 25:51Chuck Nice?

  You were just thinking about holding on.

• 25:52Speaker 02

  I was just shaking. That's what I was doing. And somehow, I was able to hold on to a handle that was in front of him. But that was a heck of an experience.

• 26:01Chuck Nice?

  Yeah. So Professor, thinking of steering and pulling the bike down. So can you go through what's happening with the gyroscopic forces of the motorcycle? And when you see guys kind of pull off, you're actually not leaning. You're pulling that bike down so that it can get on the edge to go around. Then you crane your head and you look around the corner. I don't really know exactly the principle behind that. I just know that that's how you do it, because that's how you're taught to do it. You look around the corner and the bike goes around the corner. But you're literally hanging off the bike and you're pulling it down

• 26:45Chuck Nice?

  because the bike is trying to stand up. So can you go through the gyroscopic forces that are at play there?

• 26:52Speaker 03

  Okay, so the main gyroscopic force, both wheels have the gyroscopic force on them, but the the main one that you've got control over is the front wheel. So you have the the front wheel, the tire and the wheel weigh, well, I should know the number, but I don't, more than 10 pounds. And it's spinning at fairly high RPM, so the the moment of inertia is very high. It does not want to turn. This is the experiment maybe in elementary physics labs that are done where the instructor sits on a stool that can spin around. And with just a bicycle wheel, which is much lighter, spinning at a much lower speed,

• 27:31Speaker 03

  turns the bicycle wheel, and the moment of inertia causes the the stool to spin. Motorcycle is like that, except times 100. So when you try to turn the wheel, it's trying to turn, you turn the handlebars, you try to, the wheel does not want to do this. And if you evaluate what the torques are, the torque causes the motorcycle to be pushed over sideways. And this is how you control things. You, with the wheel, you're pushing and pulling rather than turning.

• 28:07Gary O'Reilly?

  Right.

• 28:08Speaker 03

  To pull it down. And then you look into the curve and then just write your feedback. You you've learned through trial and error that if you turn it a little bit too far, you end up in the weeds on the inside, or you end up in the weeds on the outside. So you've learned through bitter experience just the right amount to turn to go through the curve on the right line.

• 28:32Gary O'Reilly?

  Right.

• 28:33Speaker 03

  And and the only difference between you and and me and a great MotoGP rider is they do this much, much better than we can even think of.

• 28:47Gary O'Reilly?

  Well, Professor, while we're sort of getting down into the physics of of motorcycle racing, we spoke about the center of gravity with Formula One race cars and how the lower it is, the better. Is there still a similar effect for motorcycles as opposed to their four-wheel counterparts?

• 29:08Speaker 03

  Yes, absolutely. So you want the center of gravity as low as possible. If you have a really high center of gravity, if you put like the fill of the, the gas tank is actually a good example, because you have a number of gallons at eight pounds per gallon, a lot of weight up high, which is what you don't want. Because there, if you can imagine, you're leaned over a little ways, but you have a moment arm with a lot of weight over a long distance from the road, which is trying to flip the bike the other direction. Ideally, all the weight would be right at ground level, and then you don't have to worry about that at all. So, many years ago, thirty years ago, forty years ago, Honda made the first Goldwing

• 29:53Speaker 03

  motorcycle, not a racing motorcycle. Yeah. And they recognized this. Everybody knows this. Everybody recognized it. But the problem is motorcyclists are very conservative. We don't buy motorcycles that don't have gas tanks where gas tanks are supposed to be. They gave the motorcyclists a fake gas tank up high, but they put the gasoline down low with a fuel pump. And so, they had the center of gravity lower where it needed to be, and gave conservative buyers the fuel tank that they wanted to think it was a fuel tank.

• 30:25Gary O'Reilly?

  Little comfort tank.

• 30:26Chuck Nice?

  Yeah, that's brilliant. What a brilliant idea. I had, I had no idea that was, that little history behind the Goldwing.

• 30:31Gary O'Reilly?

  So if, if you do, if you're able to lower the center of gravity, do you then, are you, can you, does it affect it adversely? Must do. The, the distance between the wheels, the wheelbase itself?

• 30:42Speaker 03

  The engine design affects the wheelbase. So if you have a Ducati, which has a L-shaped engine, one cylinder is facing forward, that just means you can't have the wheel, the front wheel back very far. So it, it makes for a longer motorcycle because of that. If you have A BMW has both cylinders sideways, so it's not restricting where the front wheel can be, and they're down low, so it has a low center of gravity.

• 31:15Speaker 03

  The design does affect of the performance of the motorcycle. Raymond Loewy, the designer of the Greyhound bus, the Studebaker Avanti, a great American designer, actually it was a French designer, but we claim him as an American designer.

• 31:31Chuck Nice?

  We'll let you.

• 31:32Speaker 03

  He coined the term "Maya." It was a responsibility of the designer to give the customer the most advanced MA, yet acceptable YA, design. So if you lower the center of gravity, but you take away the fuel tank, it doesn't, it may be a better design, but if nobody buys it, you failed as a designer.

• 31:56Chuck Nice?

  Wow, that's very cool.

• 31:57Speaker 03

  It's always a game, let's say, between the designers and the motorcyclists to try to sneak higher, higher performance designs onto a conservative buying crowd.

• 32:10Chuck Nice?

  So can you break this down, because Jim was telling us that in racing a car, and I know that this is the same principle in riding a motorcycle, whether you're racing or not, and that is you're going into a sharp turn, and you always brake and downshift, okay, going into the turn, and then you throttle going through and out of the turn. So you slow down, and then you speed up. So why is it always slow in and accelerate out? What, is there a physics reason for that?

• 32:46Speaker 03

  It depends on the tires. The optimum way of getting through a curve has varied with time, and not simply due to fashion. It's varied by how rigid the chassis were made at the time, how wide the tires were, and how well they, and how much horsepower an engine had.

• 33:06Chuck Nice?

  Uh huh.

• 33:07Speaker 03

  So what people have, there's this concept called squaring the corner, that the motorcycles have enough horsepower now that you can be leaning into the curve, and you, if you are one of these skilled MotoGP riders, you give acceleration to the

• 33:27Speaker 03

  The bike while you're in the curve and actually break the rear wheel loose. It skids and so it starts sliding to the outside. And and then you stop it from skidding. You automatically change the way the the direction the motorcycle was aimed from where it was to toward the end of the curve.

• 33:48Chuck Nice?

  Right.

• 33:49Speaker 03

  And so by squaring the curve this way, because you have the horsepower to do it, you can get through the curve faster. You couldn't have done that 50 years ago.

• 33:58Chuck Nice?

  Ah.

• 33:58Speaker 03

  So like I say, it's it's not a matter of fashion. It's a matter of the exploiting the technological capabilities of the time.

• 34:05Gary O'Reilly?

  So the technology has now enabled you to not just overcome some of the physics, but utilize it to your own advantage.

• 34:16Speaker 03

  Exactly.

• 34:18Chuck Nice?

  Wow.

• 34:19Gary O'Reilly?

  So now then then you go on to it. All right, OK, so this becomes function and form. We've Formula One guys will tell you it's all about the tyre dialing. The driver could be anybody, but if the tyres aren't doing what they should be doing, then this thing won't happen. What kind of evolution? Because I mean, the motorcycle tyre is is rounded and not kind of flat like a slick for an F1 car. And you're able to ride both edges of the tyre. So the the tyre technology must be vastly improved over the years.

• 34:52Speaker 03

  It it's incredibly improved. When you see a 1950s motorcycle parked next to a 2018 motorcycle, it's almost hilarious the difference in in width of the tyres.

• 35:04Chuck Nice?

  Yes.

• 35:04Speaker 03

  The tyres on a modern motorcycle is just they're just gigantic.

• 35:07Chuck Nice?

  Yeah.

• 35:08Speaker 03

  So surface area is is a major component. A motorcycle will never go through a curve as fast as a Formula One car because motorcycles only have two wheels.

• 35:17Chuck Nice?

  Right.

• 35:18Speaker 03

  And there's that limits the amount of rubber that's on the rotor at any one time. And and the wheels have to be rounded, the tyres have to be rounded to go through, whereas a Formula One car, the always there's a, you know, a linear section in contact with the road.

• 35:36Chuck Nice?

  They're flattened, yeah, flattened and and flat surface to surface.

• 35:40Speaker 03

  Yeah, and so they always will have that advantage.

• 35:43Chuck Nice?

  Cool. Man, I can't believe we're out of time.

• 35:45Gary O'Reilly?

  But before you go, Professor, I have one. Because you were involved in this art and science of the motorcycle at the Guggenheim. You must have a favorite.

• 35:54Chuck Nice?

  Oh, Gary, way to go. Oh.

• 35:57Gary O'Reilly?

  What favorite art or science of the motorcycle? Do you have one motorcycle that you look at and go, oh, yeah?

• 36:05Chuck Nice?

  What's the most beautiful motorcycle?

• 36:08Speaker 03

  Okay, so my first answer, I often get asked this, is if it's a parent, I said, you have children. How many do you have? Which is your favorite?

• 36:17Chuck Nice?

  Oh, I can tell you my favorite right now. I have three and I have a favorite right now. I'll tell you.

• 36:21Speaker 03

  Okay, so most people aren't willing to do that.

• 36:24Gary O'Reilly?

  Most people aren't, Chuck.

• 36:26Speaker 03

  Push them a little bit, they'll say, I love them equally. I say, yeah, I didn't ask you that. I asked you which is your favorite.

• 36:31Chuck Nice?

  Yeah.

• 36:31Speaker 03

  So there was a French motorcycle that, um, it was all enclosed. Every time I walked by that motorcycle, I broke into a smile. And so just based on the fact that it's such a happy motorcycle, maybe that's my favorite. But I really do like them all. I mean, that, um.

• 36:49Gary O'Reilly?

  Charles, name that beast.

• 36:53Speaker 03

  Um, look up the catalog of the art of the motorcycle. French motorcycle from the nineteen twenties, nineteen thirty, sorry.

• 37:01Gary O'Reilly?

  Nineteen thirty. Oh, so, oh, bit of art nouveau, bit of, uh, bit of modernist.

• 37:06Speaker 02

  Can I ask him one question?

• 37:07Gary O'Reilly?

  Please, Jim, ask away, sir.

• 37:09Speaker 02

  This is, this is off the record. Obviously, nobody can hear us.

• 37:13Gary O'Reilly?

  Yes.

• 37:13Speaker 02

  Except for millions of people. What's the fastest you've ever been on a motorcycle?

• 37:17Speaker 03

  Okay, so, um, I have a, I don't know the, the number because when you're going really fast on a motorcycle, you don't want to be looking at the speedometer.

• 37:28Gary O'Reilly?

  Good point.

• 37:30Speaker 03

  One night, um, in a place, there's this rule of thumb, which is so far work, that if, you don't want to speed closer than twenty miles from a donut shop. If you're further than twenty miles from a donut shop, it's probably okay. So, most of the country, you can't speed like that. There are many places like this. So one of my motorcycles, the test reports say it goes a hundred and fifty-six miles an hour. And I went flat out for twenty miles at night, uh, focused.

• 38:04Speaker 03

  On my headlight beam, because it... So I assume I went 156 miles an hour.

• 38:09Speaker 02

  Yeah, that's a good, that's a good clip.

• 38:11Chuck Nice?

  Yeah, that's...

• 38:11Gary O'Reilly?

  I, I, I do like the donut reference, thank you for that. I must admit that, that, that's, yeah, that has put, it's, it's my version of the French motorcycle.

• 38:20Chuck Nice?

  Yeah.

• 38:20Gary O'Reilly?

  Put a smile on my face.

• 38:22Chuck Nice?

  Well, dag on it, we gotta, we gotta wrap this up. But Professor, you are fascinating.

• 38:27Gary O'Reilly?

  Yeah, we've talked for ages.

• 38:28Chuck Nice?

  Let me just say, uh, stay vertical, my friend.

• 38:31Gary O'Reilly?

  Yeah.

• 38:31Speaker 03

  Okay, thank you.

• 38:32Gary O'Reilly?

  Professor, thank you so much for your time. It's, it's, yeah, been eye-opening, very much so. Thank you. Stay safe on those bikes, thank you. And to Jim Clash.

• 38:41Chuck Nice?

  Yes, Jim, thank you.

• 38:43Speaker 02

  Thank you, guys, this has been great. I learned a lot about motorcycles today.

• 38:46Gary O'Reilly?

  No, you're not alone.

• 38:48Speaker 02

  What a, what a Renaissance guy that guy is.

• 38:50Chuck Nice?

  Oh, gotta love the Professor, man.

• 38:52Gary O'Reilly?

  All right, well, that's it for our show. The physics of two-wheeled motorsport. Yeah, um, thank you. Jim, thank you to Charles Falco, the professor.

• 39:05Speaker 02

  We are art, science, physics, everything.

• 39:09Gary O'Reilly?

  Mm-hmm. We've enjoyed our show, and we look forward to our company next time.