Are you feeling curious?

Oh, my gosh.

Today on Curious Crew.

Ooh!

We take a spin.

Oh, my gosh.

How about that?

And shift into high gear?

Is this difficult?

Yeah.

To explore the physics and fun of cycling science Stay Curious!

Support for Curious Crew is provided by MSU Federal Credit Union, offering a variety of accounts for children and teens of all ages while teaching lifelong saving habits.

More information is available at MSUFCU.org Also by the Consumers Energy Foundation, dedicated to ensuring Michigan residents have access to world class educational resources by investing in nonprofits committed to education and career readiness.

More information is available at ConsumersEnergy.com/foundation and by viewers like you.

Thank you.

Hi, I'm Rob Stephenson and this is Curious Crew.

Welcome to the show everybody.

We always like to start every episode with a couple of discrepant events because discrepant events stimulates curiosity.

That's exactly right.

And I've got some fun ones for you today.

First of all, you'll notice I have this old bicycle here, and in fact, I'm going to put the kickstand up for just one second and you can see that I've got it nice and balanced.

Nava, What would happen if I let go of the bicycle right now?

It would crash.

It would crash.

Now, what would happen Nava though, if I were to give it a push and just let it go, send it off on its way.

It would crash.

I'm seeing a common theme here.

Well, you know what?

I actually tried this outside and the results might surprise you.

Check this out.

Isn't that amazing?

So Kian, what is one observation you can make when a lot farther than I expected?

It's not so surprising.

I totally agree with you.

Now I have something else I'd like to share with you today.

How many of you have seen a unicyclist ride up close?

Anybody?

Oh a couple of you have So you're in for a treat.

I have a unicyclist here in the studio.

Kiera, come on out.

She's going to demonstrate some of her talents.

But first, I have a question for you Kiera.

How long have you been riding the unicycle?

About two years.

About two years?

Okay.

Go ahead and show us what you can do.

It's pretty impressive, my friends.

Watch close.

Oh, my gosh.

Oh, look at that.

I never understand the turns.

Yeah, it's just amazing.

I have to lean on one side.

Yeah.

Good noticing, good noticing.

Look at that.

Amazing.

So Xanna, what's an observation you can make?

She made it look so easy.

How does she do it?

I know.

It's really impressive.

So we've got this riderless stability and our one wheel wonder.

I'm gonna invite three of you to do a little scientific modeling to see if you can explain these phenomena By the end of the show.

You can use your background, knowledge, anything that you learn along the way.

So who would like to participate in a modeling moment today?

Okay.

Krishaan, Olivia and Jackson?

Great.

Anybody have a guess we're going to be investigating today?

What do you think?

Xanna, what do you think?

I think we're going to be investigating something about balance.

Oh, balance is certainly at play here.

We're going to be investigating cycling science.

Stick around.

It's going to be quite a ride.

All right.

Let's see if we can figure this out.

I was surprised that the riderless bike went for so long before falling over.

I know.

I'm sure the sloped ground helped, but I expected the wheel to turn hard one way and then the bike would fall and crash.

Me too.

Did you notice that Kiera had to pedal the entire time on the unicycle?

She must have really good balance.

The bicycle was first invented in Germany around 1817.

It was called the running machine, but there were no pedals.

Riders kicked their feet along the ground to move it forward.

By the 1870s and 1880s, people were riding the penny farthing bicycle with the huge wheel in front.

But by the 1890s, the safety bicycle was engineered.

It had a free seat handlebars, two similarly sized wheels and a chain driven pedal system Look familiar?

Even with today's minor changes, that classic design keeps rolling.

So if we want to make sense of that phenomenon, a good place to start is by looking at a bicycle right?

Now, most geared bikes are really sophisticated.

I got a question for you.

Anybody have a guess how many different parts there are on a geared bike?

Kian, what do you think?

Oh, I don't know, like 243.

I love how specific that is.

This might surprise you.

There can be over 800 different parts on a bike.

That's a lot in one system.

But if we start thinking about bikes, we like to think about subsystems.

Let's take a look at some of the subsystems here.

So first we have the frame, got those tubes, stays back here, then you have the fork that goes down here and up through the headset.

Now, up here on the handlebars, there's a lot going on.

We got steering parts, we've got shifting parts, we've got braking parts.

And then down here we have the drive train and of course the wheel tires and finally the saddle for the seat.

But the amazing thing is all these 800 pieces have to work together as a system in order to function.

Now, Krishann, I'm going to ask you to do me a favor.

Can you go ahead and hop on the bike?

Because he's already ready.

He's already got his helmet on.

And I'd like you to go ahead and start pedaling and tell me, what are you noticing?

Is it easy or is it difficult?

It's really easy.

It is because it's in low gear.

And so what would happen if we put this in higher gear, Sariah?

I think it'll be harder.

Okay, Go for it Krishaan.

Let's crank it up.

It's going the other way.

There you go.

Oh, nice.

You can see that drive, train and action over there.

Excellent.

What are you noticing now?

It's really hard.

It's really hard.

I won't make you do it for a really long time.

Let's go ahead and brake it and you can step right off.

And I want us to think about this, of all of these parts.

Let's focus on gears for just a moment.

I'm going to step a little bit closer and we're going to think in terms of what's called the gear ratio.

Now, to find a gear ratio, we need to look at the cog that's in the front with all those teeth, and we have to compare it with the cog on the back that the chain is on.

Now, if we count that front cog all those teeth and we take that number and divide it by the back cogs, the number of on that team, we can figure out the ratio.

Now, here's a question I have for you Kian.

Let's imagine Krishaan wants to cover a lot of distance.

Do you think he'd be able to cover a lot of distance in a low gear or in a high gear?

I think it's high gear.

You are guessing correctly.

And here's why.

If we put one pedal all the way around, one revolution of the pedals, we move that car once and let's pretend this is a 5 to 1 gear ratio, 5 to 1.

That means one pedal would move the bat cog five times, which means the wheel would rotate five times.

And if this were a racing bike, you could cover 35 feet in one pedal revolution, which is kind of crazy.

So here's another wondering I've got for you.

Now he just stepped off the bike and it's in high gear right now.

Sariah, if he were to get back on and start pedaling, do you think it's going to be easy or hard?

Hard.

is sometimes when we stop, we have it in a high gear and it's like, Oh my gosh, I can't get going.

The other thing that's really funny is if you're already going super fast and you put it in low gear, your legs are like flying around, but they're not really doing anything.

So here's the best advice.

You always start in a low gear and as you gain momentum, gear it up and you can cover more distance.

The addition of gears has made this a great system, and shifting gears on a bicycle is a great way to travel quickly.

Using bigger bicycle wheels is another way to increase speed.

A large 27 and a half inch racing wheel covers more distance with each revolution of the pedal.

That's great, except when going uphill, those bigger wheels will make it harder.

That's why a mountain bike or BMX wheels are smaller.

Those riders go up and down a lot on difficult terrain and sometimes even stand on the pedals to push harder on the cranks.

They know that more force can also get more speed.

Wow.

Are you curious about careers in science?

Hi.

Im Aikem and today we're here with Laura Harris.

Laura telling where we are.

And what do you do?

We're in cross-country cycle in Holland, Michigan.

This is my bike shop and I am the owner manager of the store.

I'm a bike mechanic, a salesperson, and I'm a bicycle fitter.

Wow.

It's a lot of jobs.

What are some benefits to biking Biking is a wonderful way to get physically fit.

Also, it's such a good way to have good goals.

You're going 11 miles an hour.

Awesome.

See mom not all video games are bad.

That's right.

And then of course, spending time with friends.

Why is bike fitting so important?

Bicycle fitting is so important so that you can have more fun on your bike so you can be faster and more comfortable and most importantly, so that you don't injure yourself.

This is the right size for you.

So how does the fitting process work?

So first of all, have you wear some cycling clothes and you come and bring your bicycle?

We set you up on a trainer in the back and then I analyze your body, What are you stickered for?

So I'm going to stick this on you so that I can put sensors on your body and then I can see how your body is moving in 3D.

And then we take that information and we reposition your bicycle with all of the accommodations that we need.

I feel like a science experiment.

What aspects in STEM are involved in bike fitting?

Well, in bike fitting, I have to know so much about the human body.

I have to know math and geometry.

I already feel so much better in the back.

Isn't that amazing?

And then, of course, I'm a bike mechanic, so I have to be able to know the mechanics of how the bike works and what can be adjusted.

All right.

Are you ready to ride?

I'm ready.

I'm really passionate about my job because I feel like I can make a difference for people.

I just love that I'm helping people have their best life.

Laura Harris showed me how STEM and cycling are a perfect fit.

Explore your possibilities!

And now back to Curious Crew.

so when I was a kid, I used to love riding around in circles on my bike, in the driveway, sometimes doing a figure eight.

Did you guys ever do something like that?

Yeah, it's kind of fun.

Okay, so imagine I'm riding along happily pedaling and I want to turn to the left.

What am I going to do?

What am I going to do?

Aikem can you just grab the handles and you show me?

What am I going to do?

Turn your handlebars to the left so the wheels go left.

Yeah so the wheels turning to the left?

I don't want to be too sharp because what'll happen?

You'll just crash.

Okay, so that won't be a good idea.

So you guys all agree.

You turn to the left when you want to turn away.

You know, I used to think that was true until someone videotaped me in slow motion turning.

Check this out.

Kind of surprising.

They're right.

Okay.

Nava, what did you notice?

The bike turned the opposite direction before I would turn the direction it wanted to go.

Which is really strange.

We call this counter steering.

Why would I turn to the right to turn to the left?

Or why would I turn to the left to actually turn to the right?

Let's think about what's going on here.

Imagine I want to turn to the left.

I started by turning to the right and my body has to lean the other way so I don't tip over.

But once I'm leaning to the left, I can now steer to the left and the bike will come back underneath me and I can continue on my way.

What's amazing is most people don't realize they counter steer and we don't even realize it ourselves.

You do it unconsciously every single time you turn.

Okay, we can show this another way.

Jackson.

you're probably wondering, why did Dr.

Rob hand me a mop?

You've been holding a mop this entire time.

Jackson, I want you to try to balance this on one hand and try to take a few steps forward and tell us what you notice.

Okay.

What did you notice?

Well, I noticed that like when it started to lean forward, I had to move with it so that I could be stable.

Outstanding.

So you're stepping into that lean just like counter steering on a turn on a bicycle.

So remember, steering is not just direction, it's also balance.

One thing's for sure, cyclists eventually will want to stop.

Most bicycles use a caliper operated rim brake system when the rider squeezes the brake levers, cables close a pair of rubber shoes on either side of the wheels rim.

The metal rim slows down, while its kinetic energy transfers in to keep from friction because the shoes rub the fast spinning outer rim, it doesn't require much force to stop heavier disc brake systems, stop the wheel closer to the hub, so they need more force to slow the wheel down.

Well, looks like it's time to get going again.

Boink.

Whoa!

A lot of what we do on Curious Crew just involves simple things that use from day to day.

Like one of the episodes I was on was about soap.

If we're studying soap and science, it only makes sense that we make soap.

we picked a soap base, a fragrance and like a color and poured it into a mold.

I remember I chose shea butter and like the pigment for it, and it turned out really cool.

You end up with beautiful, fragrant soaps that you can use at home.

It's cool to see like how the steps that you took to get there lead to the finished result.

So it looks like your soaps turned out great you guys.

Those are beautiful.

Nice job STEM Challenge.

so have you been having fun investigating cycling science today?

Yeah.

I'm so glad I've got a really creative challenge for you today.

In fact, a lot of cyclists like to accessorize their bicycles to make them kind of flashy and look really good.

You are going to be trying something similar.

You're going to be doing some spoke decorations on the front wheel of a bicycle.

And I think every table has a plan, right?

Okay.

Go for it.

Have fun.

We can we count how many that we need?

Yeah, that's what we're going to do.

We're going to lay them out.

I'm starting with red.

I think it's going to look so cool when he puts it on because you can see all the colors.

It will blend, the colors.

Yeah.

Dr.

Rob has a us decorating these tires to make them pretty.

I'm getting a little excited.

Each group had different materials, but our group, we had just pipe cleaners.

Our table, we had paint chip cards and we had tape.

We are using a whole bunch of straws.

I think thats good.

Oh, it went in ka-pow.

We just decided that the easiest way to do it was to like, tape together the paint chip cards and then place them down and then tape them to the side.

Okay, I just made another one.

So now I have five.

Okay, that's good.

I feel like if we ever need extra, add a couple of yours.

We went back and forth between braiding three pipe cleaners at a time together and just twisting them, but we eventually settled on just twisting them and then winding them around the spokes because it was more time efficient.

I forgot about the bottom one.

Yes the bottom one.

The biggest challenge is to get them on, because when we tried to put them on, they just wouldnt stop closing.

This is hard.

Does it like me?

Me neither.

Ooh.

We worked really well together.

We were very cooperative.

Okay.

All right.

(gasps) At least its taped together.

We think that it's cool because the straws keep going tic-tac, tic-tac when it moves because it keeps going against the metal spokes.

Yeah, Yeah.

You should cut the green one, But then I think we're done.

Oh, wow.

These are looking pretty great.

So I think you're just about finished.

And I've got a great way for us to showcase these beautiful, spoke decorations.

I think you're really going to like it.

So these wheels look excellent.

First of all, your table, Krishaan, What did your team use here?

We use cut straws.

Cut straws.

And did you decide on a pattern?

What did you decide?

So we started off with some sections of the same color, but in the middle of building we decided to go crazy with all different colors.

I love crazy with all different colors.

Let's see this in motion.

Oh, yeah, that's that's really cool.

And it actually makes a little sound as the straws are clicking up and down.

That is really, really neat.

Very fancy spoke decoration there.

Excellent.

Let me take a look at this one.

And Aikem, What materials did your team use here?

We decided to use a lot of pipe cleaners.

Pipe cleaners.

And tell me about this up front.

What's this?

So we've got a spider on a spider web.

A spider on a spider web.

Let's take a look if the spider can survive.

Oh, my gosh.

How about that?

It clings right to it.

That is really neat, isn't it?

And we've got one more to show.

Think about all these great ideas that our viewers are going to get here.

Let's take a look at this one.

Okay, Jackson Thanks.

Xanna, what materials did your team use We use a lot of paint, chip cards and tape.

A lot of tape, Which gives it a really cool, iridescent look, actually, when it rotates around.

Oh, now that's really interesting.

And I can go this way, too.

And you guys did it on both sides, which makes it really, really colorful.

I think you might have given our viewers some really good ideas.

Try decorating your own spokes and you can be riding in style.

Spoked bicycle wheels combine high strength with lightweight.

However, the spokes are under a lot of tension.

When you sit on a bike, your weight is carried down the frame to the wheel hubs where the spokes connect from the rim.

That weight is not evenly distributed because the vertical spokes at any moment are carrying the load as the wheel turns, the top spokes stretch the side ones relax while the bottom spokes compress.

And that happens over and over.

Spokes keep the wheel round and prevent it from buckling.

And as we've seen, they can get decorated too.

Do you remember learning how to ride a bike yourself?

Yes.

Yes.

What was the hardest thing to master when you were learning?

It was the balance.

The balance is really hard and it's key with cycling science.

Now I've got a little challenge for you.

Xanna, i'm going to ask you to climb on the bike and see if you can balance while it's stationary.

I'll spot you, I promise.

Okay, You go ahead and see if you can climb up there, get the kickstand up.

Perfect.

And we'll spot you a little bit.

Okay?

What do you notice in here, Olivia?

What's she doing?

She's not actually sitting on the bike.

Okay, That's a really good noticing.

Is this difficult?

Yeah.

Oh, a little bit.

A little scary, isn't it?

You're doing something that is called a track stand.

A track stand.

And one of the things that you're doing that's really great is you've got the tire turned a little bit.

You have the pedals set up at three and 9:00.

Your arms are almost straight.

And I can actually feel you shifting your weight from pedal to pedal.

Nice job.

Go ahead and step off of there, Xanna.

Excellent job.

Now, you might be thinking, okay, why would someone want to know how to do a track stand?

Well, some times there are cyclists who have clips on the bottoms of their shoes, which means they're actually attached to the pedals.

Now they're rolling up to a stoplight and they don't want to unclip.

You have to be balanced.

Right?

And so learning how to do a track stand is really, really tricky.

Most of the time we're moving on our bicycles and that's what's establishing the balance.

So I wonder if this would be possible on a unicycle.

Kiera, can you come on out?

Now let's see what Kiera can do here.

Notice how she starts.

Oh, look at that.

Unbelievable.

And see you later.

Okay.

What did you notice, Olivia?

What did you notice?

I noticed that she was using her arms to help with her balance.

Okay, great.

Xanna, did you notice anything else?

She kept on going back and forth.

Excellent.

So you might have noticed when you were on the bike, you were thinking about side to side balance.

But Kiera was thinking about forward and back balance, which is really interesting and of course, balance is an important part of cycling science, right?

In fact, it's a balancing act.

Cycling is a sport where riders can start early, being pulled in a bike trailer, riding a tricycle, balance bike, bike with training wheels or a trail-a-bike.

Cycling options continue too.

You can ride road bikes, mountain bikes, fat tire bikes, race BMX, recline on a recumbent take a friend on a tandem, impress on a unicycle or relax with an electric as Albert Einstein once said, life is like riding a bicycle.

To keep your balance, you must keep moving.

Are you curious about careers in science?

Hi, I'm Genesis and today I'm here with Master Q, Quiana Powell.

Quiana, can you tell me where we are and what you do?

I am a master instructor in the art of tang Soo do, is a Korean style of martial arts and we are at Double Dragon tang soo do academy in Burton, Michigan.

Ay-yem I am the first African-American female master in our World Tang Soo Do Association.

How is STEM involved in martial arts?

STEM and martial arts surprisingly go hand in hand.

So here's where that angular momentum comes from.

Okay.

Whether we are preparing to do a basic front kick or a straight punch, all my energy, I built all my energy up and I'm pushing it forward.

I'm breaking through a board.

Why are you so passionate about tang soo do?

I love children and I love being able to help them.

any way that I can do that by way of martial arts it's even better.

Master Q Help me on my white belt in tang soo do and physics today.

Explore your possibilities.

Now back to Curious Crew.

So both discrepant events has to do with balance.

I think so too.

Did you notice how Kira had to lean forward and back when she started and stopped?

Yeah, And there's no drive train on the unicycle, so she can't ever coast.

You're right.

Dr. Robs riderless bike definitely had momentum from rolling down the hill.

I think motion helps keep it in balance longer.

So have you had fun investigating Cycling Science today?

Yeah.

I'm so glad.

It's now time to roll back to these discrepant events to see what we figured out.

So, Jackson, how can we explain this riderless stability.

How can the bike go so far before tipping over?

So when the bike begins to lean, the handlebars move the same way?

Just like when you turn on a bike, you have to lean into the turn so you can keep rolling.

The bike was able to correct itself and go longer before tipping over.

Okay, good thinking, my friends.

So it's really interesting to think about this, but the best way to explain this is to shoulder the bike.

Bikes are actually pretty stable devices.

Now if I imagine just the front half of the bike for a second, the center of mass is actually in front of the fork.

That means if the bike tips slightly to the right, you'll notice the handlebars turn to the right.

If it slips goes slightly to the left, the handlebars will turn to the left.

And that's what happens as it's going riderless.

But there has to be enough speed to keep it in balance.

And that's why it worked better on sloped ground.

That's exactly right.

So if I've got the sloped ground I have gravity helping me out.

And you probably noticed when it got to the bottom of the hill, it lost that speed and then eventually the wheels turn and it crashed.

So what can we explain about our one wheel wonder.

Krishaan, what do you think?

The unicycle is direct drive.

So she had the pedal the entire time.

To start she had the lean forward and push.

To stop to the lean back and step off.

Very good noticing.

And you probably also notice that she really has to think about her posture, right?

She rides with a straight back.

I think we should watch one more time.

Kiera, come on out.

Look at that.

She just makes it look so easy.

Just like Xanna said.

It's just amazing.

Unbelievable.

One more round of applause for Kiera, our unicyclist.

That was awesome.

Nice job today, crew.

So remember, my friends Stay Curious and keep experimenting.

Get your curiosity guide and see more programs at wkar.org Support for Curious Crew is provided by MSU Federal Credit Union, offering a variety of accounts for children and teens of all ages while teaching lifelong saving habits.

More information is available at MSUFCU.org also by the Consumers Energy Foundation, dedicated to ensuring Michigan residents have access to world class educational resources by investing in nonprofits committed to education and career readiness.

More information is available at ConsumersEnergy.com/foundation and by viewers like you.

Thank you.

1003 investigation number two, take one.

Yeah.

All right.

Oh, my gosh.

Wasnt that cool.

Okay, So.

(laughs) Oh, man.

Tim gets to slate.

He's retiring.

Take one.

(Claps) Great job Tim.

Thank you, Tim.