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Video Pick: Flywheel Bicycle

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Video Pick: Flywheel Bicycle

Video Pick: Flywheel Bicycle

Video Pick: Flywheel Bicycle

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  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

Maxwell von Stein, a 22 year-old Cooper Union graduate, built a bicycle that uses a flywheel to store energy. Instead of braking, he can slow the bicycle by transferring the kinetic energy from back wheel into the flywheel—which spins between the bars of the frame. Then Max can send the flywheel energy back to the wheel when he wants a boost.

IRA FLATOW, host: Up next, Flora is here. Hi, Flora.


FLATOW: Flora Lichtman, with our Video Pick of the Week. What have we got this week?

LICHTMAN: This week, how to boost your bicycle.

FLATOW: And then boost your...

LICHTMAN: OK. That sounds self-explanatory.


FLATOW: This is...

LICHTMAN: We can give you a little more.

FLATOW: This is SCIENCE FRIDAY, from NPR. And how to boost your bicycle. That doesn't mean steal it, right?

LICHTMAN: No. Well, no. We are not telling you how to do that. You wouldn't want to boost your own. But it's the story of 22-year-old Maxwell von Stein. He's a graduate from The Cooper Union here in NYC and studied mechanical engineering. And basically, what he did was attached a flywheel to his bike. So it's a big, metal...

FLATOW: Heavy wheel.

LICHTMAN: ...wheel. And he put a transmission on the back hub of his bicycle wheel that allows him to, instead of braking, take the energy from that back wheel and put it into the flywheel, flowing down the bike.

FLATOW: Just like my Prius or, you know, the...

LICHTMAN: Regenerative braking.

FLATOW: ...regenerative braking. But, so he - so when he brakes, the energy from him moving forward in - with the wheels goes to spinning up the flywheel.

LICHTMAN: Spins up this heavy, 15-pound flywheel - which, by the way, is located in between the crossbars, right between your legs, which is another thing that makes the bike different from other bikes. And then that flywheel stores the kinetic energy. And he can actually transfer it back. So if he's going up a hill or something, he can give himself a little boost.

FLATOW: Little boost. So he doesn't have to paddle as hard...

LICHTMAN: Exactly.

FLATOW: ...going up the hill and above. Of course, that's going to use up some of the energy in the flywheel.

LICHTMAN: Right. And then you can power it up again as you...

FLATOW: As he goes down the hill.

LICHTMAN: As he goes down the hill. And it's really a pretty elegant, little design, I thought.

FLATOW: Wow. Wow. And you can see this on our Video Pick of the Week. It's up there on our website at SCIENCE FRIDAY. And he's bicycling around. And he had to design the whole system himself?

LICHTMAN: Yeah, he - I mean, you know, he took some parts of bicycles that already exist, but he machined a bunch of the things like the chain wheel - the chain ring adapter. And so the video also features - if you like tools, this is a good video for you...

FLATOW: Ah, yes. Cool.

LICHTMAN: ...because there are a lot of cool tools at The Cooper Union machine shop, as you might imagine.

FLATOW: And - but flywheels are - I'm sure you've discovered, this is an old technology, right?

LICHTMAN: Well, that's what I said. I was like, this is - why are, you know, this is kind of low-tech. And he said, well, you know, my version is low-tech. But actually, his dream is to bring this concept to cars. And he said that some car companies are experimenting with the flywheel, because it's cheaper than batteries, and it's lighter than batteries. And so that's sort of his idea for this.

FLATOW: And it delivers a huge amount of energy in an instant of time, just when you need it, it'll deliver a lot energy.

LICHTMAN: Yeah. He says a kick in the pants.

FLATOW: A kick...

LICHTMAN: It's how he describes it.


FLATOW: I know they're experimenting, you know, and I remember even going back to the '60s, that they've tried to put flywheels into cars. And maybe now that - his idea is actually right, to see if he could make a flywheel car or that - see how that might work.

LICHTMAN: Yeah. And for - and, you know, we've already had a comment on our website about this. And they said that - the person said, you know, that's great for cars, but I like this for bikes too.


LICHTMAN: Why not? And for New York, it's perfect, because they are...

FLATOW: Let's not write off the bike business.


LICHTMAN: Yeah. Yeah.


FLATOW: So good thing, because I think it's a great idea. Maybe you make a bigger flywheel, you know? You have to trade up between the weight of that thing on the bike.

LICHTMAN: Right. I think that's - you're pedaling around some extra weight. But if you're doing a lot of stopping and starting, like you do in New York City, like riding in traffic, this is really - you can see why this would be helpful.

FLATOW: Yeah, because it's that first push from stationary that's the hardest part of getting on a bike and riding it.

LICHTMAN: Yeah. And you're constantly slowing down for cars and speeding up and - yeah.

FLATOW: And go see this, our Video of the Week. It's up there on our website at You'll find it following the "Where's the Octopus?" video, still being viewed.


LICHTMAN: One more little plug for that.


FLATOW: One more for that. It's breaking quarter million views. And it's up there. And it's really - I think it's a great idea. I think this is going to catch on. It's something - everybody can do their own.

LICHTMAN: Oh, I hope so. And you know what? Maxwell von Stein - this is a classic case of why he was in front the camera. He is a really a smart kid. You can tell.

FLATOW: All right. Our Video Pick of the Week up there at SCIENCE FRIDAY. Thank you, Flora.

LICHTMAN: Thanks, Ira.

FLATOW: And while you're there, you can download our iTunes and podcasts of the video. And we do podcasts of our audio shows. And also there, you can join our website and log onto our Twitter, and also join folks on scifri at our Facebook account. So that's about all the time we have for today. Stay with us. Next week, we'll be right back. If you want to send us some email, you can send us at Also, you can send us with the regular, old-fashion way, SCIENCE FRIDAY, 4 West 43rd St., Room 306, New York, New York, 10036. Have a great weekend. We'll see you next week. I'm Ira Flatow, in New York.

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