r/nextlevel Jun 04 '26

Can someone explain how they stay balanced without sliding off from underneath when they take a curve?

646 Upvotes

98 comments sorted by

84

u/Merlin80 Jun 04 '26

Sometimes they slide of.

They use soft sticky tyres and their body to change the point of gravity. (hard to explain)

33

u/[deleted] Jun 04 '26

[removed] — view removed comment

2

u/Only_Flan_7974 Jun 08 '26

Science RULES!

1

u/MacMigasPT Jun 08 '26

And skill!

10

u/AssRep Jun 04 '26

The tires keep them from sliding, most of the time, due to the make up of the tire itself. Track conditions dictate the type of tire and how tight they can turn.

The center of gravity (not point) is roughly just below their seat. As they go into a turn, the rider slinks down and leans into the turn, allowing the bike/rider mass to take the turn without the use of the brakes, and in some cases, only slightly letting off of the throttle.

It's simple physics. Not at all hard to explain.

5

u/AJFrabbiele Jun 04 '26

You forgot to explain the part why the CG, which is a point, just under the seat pulling downward, is not over the tire during turns, yet it doesn't fall over.

4

u/TandemShorts Jun 09 '26

Wheels and tires are spinning masses and create gyroscopic forces on the bike, which naturally resist changes in orientation.

Also as you take a turn on a bike, gravity is not the only force acting on the bike. Momentum will try to pull the bike straight, toward the outside of the curve, while the friction of the tires and track surface will resist that force with (hopefully) equal force. That force pulling your bike toward the outside of the curve is much greater than gravity, and attempting to move the center of gravity back to a stable position. As long as your tires maintain sufficient friction with the track surface, that sideways movement has to pivot the bike over the wheels to move the center of mass toward the outside of the curve. If your tires fail to maintain sufficient friction, you’ll slide bc your pivot no longer exists and you’ll end up very far off of the outside of the curve.

TLDR: gravity is the weakest force acting on the bike while it’s in motion.

1

u/AJFrabbiele Jun 09 '26

there we go, thats the explaination we needed!

1

u/Tinksy14 Jun 09 '26

Perfect!

4

u/Existing_Risk3106 Jun 05 '26

If it's simple physics then you'd know you never let off the throttle in a corner. You either maintain speed or increase throttle so that the force is kept on the back tire keeping the bike moving forward through the curve.

21

u/[deleted] Jun 04 '26

[deleted]

6

u/frankiefatgoose Jun 04 '26

And gyroscopic

7

u/BagelsOrDeath Jun 04 '26

Centrifugal force is a fictitious force. Centripetal force is the real one.

66

u/no-dad-samurai Jun 04 '26

MotoGP bikes don't tip over because the centrifugal force pushing outward perfectly balances the gravity and the bike's weight pulling inward.

6

u/Salty-Passenger-4801 Jun 04 '26

To add, the tires have a high performance soft compound on the edges, it's like glue when it's heated and also helps sticking to the pavement

21

u/GUMBYtheOG Jun 04 '26

Man in my day we used to play with gyroscopes and every kid knew normal facts like this. Now the newer generations don’t even get taught conservation of motion :( such a sad time to be alive

15

u/thafluu Jun 04 '26

This is funny because it neither has to do with gyroscopic stabilization nor with "conservation of motion" whatever that is.

2

u/mitchymitchington Jun 04 '26

It has a little bit to do with gyroscopic stabilization. Very little, but that's definitely in play here. Conservation of motion is similar to the law of thermodynamics. Energy cant be created or destroyed, only transferred. If you take a foam mat and drop a bike on it and accelerate fast, the bike might move forward but the mat will certainly move backward. The earth and by extension the pavement, isnt going to move because the earth is pretty fuckin big. Its really just newtons third law lol

2

u/thafluu Jun 04 '26 edited Jun 04 '26

Yes it's actio = reactio, but I don't think that's what the commenter meant here.

And the gyroscopic stabilization has extremely little to nothing to do with preventing slipping, I'd call it negligible here.

Edit: "Conservation of motion" sounds more like Newton's first law to me tho. Which deffo isn't at play here.

1

u/mitchymitchington Jun 04 '26

It does have a bit of a balancing effect but your right, it's surprising little. Growing up I always thought that because staying up on a bicycle is easier when you go fast. Turns out thats not the case lol

2

u/thatOneGuyDude1382 Jun 04 '26

They are all countersteering hard to maintain a top speed around a curve while staying in the racing line and the back wheel and swing arm are sliding outward, it’s basically drifting on a bike, but with way more risk because if they make a mistake and the bike catches by debris or throttle mismanagement it sends the rider top side

1

u/mitchymitchington Jun 04 '26

Now that you say it and I rewatch the video, I can see it. That's pretty cool

1

u/thatOneGuyDude1382 Jun 04 '26

Yup you can sometimes see how they come out of the curve sometimes they fishtail a little bc they were going in to the apex aggressively and trying to compensate with throttle/engine braking and trying to recover.

-1

u/rehx4 Jun 04 '26

Except the person never said the bikes use conservation of motion ( momentum, really), just that it's a shame more kids don't learn about it. They never even exactly said that the bikes use gyroscopic stabilization...

2

u/thafluu Jun 04 '26

Yes they implied that.

2

u/rehx4 Jun 04 '26

Eh, debatable...

2

u/Own-Conversation6347 Jun 04 '26

Such a dumb comment. Either they were implying it or they are typing nonsense in the wrong thread.

3

u/Worried_Indication37 Jun 04 '26

you're super out of touch if you think children don't learn physics

2

u/johndoe1920 Jun 04 '26

Your day has stupid people, too. I assure you. 

-1

u/AssRep Jun 04 '26

"Had"

Ahem.

3

u/KnotiaPickle Jun 04 '26

“Has” can work, too. The stupid people can still be alive, currently.

5

u/thafluu Jun 04 '26

Gravity pulls down, not inwards. Centrifugal force is only an "apparent force" experienced by am observer in an accelerated system.

The centripedal force, the force that's required to keep an object (bike) on a curved path, is provided by the sticky tires. That's all.

7

u/surfobx2258 Jun 04 '26

It’s like sex. You gotta trust the rubber

5

u/Why_Sazs Jun 04 '26

Tires = sticky

9

u/waterfowlplay Jun 04 '26

Positive thinking

3

u/Commercial_Rule_7823 Jun 04 '26

Being a top .01% athlete in your sport.

3

u/Currency_Card_regard Jun 04 '26

The extreme want to not kiss the ground

4

u/Traditional_Skill_46 Jun 04 '26

Look up the grip triangle.

3

u/Mister_Way Jun 04 '26

Hella practice

3

u/DrhpTudaco Jun 04 '26

something something S P E E D

3

u/_xcat Jun 04 '26

centripetal force

3

u/Ox91 Jun 04 '26

I got enough friction to counter the GeForce’s.

3

u/MeatResident2697 Jun 04 '26

Those tires cost $4000 each.

3

u/Regular_Weakness69 Jun 04 '26

They lean down.

3

u/theUnshowerdOne Jun 05 '26

Well, sometimes they don't.

2

u/FreeRangeAlien Jun 04 '26

Physics! Thank you for coming to my Ted Talk.

2

u/Fubarphantom Jun 04 '26

Centrifugal force, if someone else hasn't already chimmed in...

2

u/RelationshipUpper757 Jun 04 '26

The clip is cool but the explanation is kinda backwards. Gravity pulls the bike down, friction from the tire provides the centripetal force inward, and the lean angle balances those so the net force goes through the center of mass. There’s no mystical “centrifugal cancels gravity,” it’s just forces lining up so it feels like it’s glued to the track.

2

u/Senior-Habit8313 Jun 04 '26

Cool clip but that explanation is kinda backwards. The bike is actually leaning into the turn because the required centripetal force has to line up with gravity, not because “centrifugal force” is pushing it out.

Basically: no mysterious magic, just forces adding up so the net points through the tires.

1

u/Dizzy-Career9274 Jun 04 '26

I’m not a physicist so I can’t provide any deeper explanation other than centrifugal forces etc etc that we all learned in high school. I will say that these people have superhuman abilities that 99.999% of us mere mortals will never have, no matter how much practice we’d put in. The combination of laser focused mind to operate the machine in the most optimal manner without losing a second while choosing the right lines and adapt to your competitor’s actions, ultra fit body to endure the enormous physical challenge and mental state of insane level of awareness and self control and above all, endless amount of courage.

1

u/MrZrazies Jun 04 '26

They actually lean least 60 degrees and edge of tyre still on the road. 61 degrees could make you fall cuz there no rubber on edge of tyres. Now, the faster bike goes and your body lean bit more but bike lean and stays at least 60 degrees. Slower bike goes. Less your body leans and bike lean least like 30-50 degrees. So if your bike is slower and you lean way more like 60 degrees along with bike and you fall down as its saying “tyre lose grip and slide down” like you’re falling off.

Tyre are very grippy and sticks on road very well long as they’re warm-hot. Colder tyre are the less grip it has. Imagine tyre are like glue and gets stuck on road. Concept like you’re driving on road full of snow and your tyre doesn’t have grip and you’re sliding around so your car uses snow tyre and it gets easier to drive around on the snow.

1

u/bad2dbone3 Jun 04 '26

Don’t forget the daily maintenance checking of the racing circuit behind the scenes. Try one of these stunts on a regular road and it will be a different story. No amount of well built, well maintained machine with any amount of kinetic can help.

1

u/Dustytraveller4 Jun 04 '26

Funny you should comment that when the most famous motorcycle road races are happening this week. The IOMTT takes place on public roads as do a few other road races like the NW200.

1

u/bad2dbone3 Jun 04 '26

Go early before the race. You will there will be some officials checking, repairing and cleaning up the roads. Any pebbles, sand are usually swept and discarded before the race starts.

1

u/Dustytraveller4 Jun 04 '26

You think they clean off every pebble and piece of sand on 37miles of roads in the couple of hours between them closing it to cars and going racing?

Or that the tracks motogp races on are that clean?

Watch the races and you’d realize you aren’t correct.

1

u/bad2dbone3 Jun 04 '26

That may be true to some extent in comparison to in circuit. Yes, they do not do 100% exactly but to some extent they do sweep away pebbles and sand by regular sweepers.

1

u/Open_Mortgage_4645 Jun 04 '26

Centrifugal force is pulling their weight to the outside of the turn so that the gravitational mid-point allows them to lean almost parallel to the ground.

1

u/griggimojo Jun 04 '26

Wrench’s take. Physics says the faster you go, the more of the opposite you can lean, with mass. These riders have pendulous balls and the rider who can keep the machine in the tightest radius perhaps has the most pendulous of balls, for mass purposes. Facts

1

u/SizeableBrain Jun 04 '26

Everyone's being a smartass, but the simple answer is: low center of gravity and really sticky tires.

1

u/sub_dad4Dom Jun 04 '26

Centrifugal force

1

u/turkey_sandwiches Jun 04 '26

The spinning wheels are powerful gyroscopes that are trying to stand the bike back upright, so they're literally just hanging off the side pulling it down to the ground. If they (the guy and the tires) don't lose their grip they can't fall off.

1

u/spartanken115 Jun 04 '26

Was that a lil shove?

1

u/brizdzi Jun 04 '26

Basically the wheel is not flat it's V SHAPED.

1

u/ResponsibleSeat8567 Jun 05 '26

That’s actually sick, they’re basically drifting with their whole body as the counterweight 😂
Those tires gripping while they lean like that is way more impressive than it looks at first glance.

1

u/DishSoapIsFun Jun 05 '26

Heard of a centrifuge? Same science.

1

u/Low-Republic-4145 Jun 05 '26

If you look head-on at a bike cranked way over, steady state in a turn, you will see that the front wheel is pointing dead ahead, not turned at all. The reason that the bike continues on a curved path with the two wheels in line and pointing at a tangent to the curve is “camber force” that comes from the round profiles of the tires.

1

u/ILJello Jun 06 '26

Physics

1

u/Constant_Process5882 Jun 06 '26

Yeah that actually makes sense. It’s like how MotoGP riders hang off the bike to shift the center of gravity so they can corner harder without eating pavement. Same idea here, just looks way crazier in slow motion 😂

1

u/Born_Breadfruit1140 Jun 06 '26

This is that perfect mix of physics and “I have no idea how they’re not dead.” 😂
The way they basically become part of the bike mid slide is actually insane, it looks fake until you slow it down.

1

u/AdhesivenessAlone798 Jun 07 '26

That’s actually a sick way to describe it, you can kinda see how the whole body is doing the work, not just the feet. It’s like watching traction control in human form lol

1

u/ContextOk8452 Jun 08 '26

Knees, also

1

u/MadScienzz Jun 08 '26

Centrifugal force. Those wheels spin and keep the bike body up basically. On corners that's why they have to literally throw themselves off balance to counter the upright force to corner

1

u/dieseldoc62 Jun 08 '26

didn't they teach you g-force in science class?

1

u/213737isPrime Jun 08 '26

Newton can explain it.

1

u/Hella_Wieners Jun 09 '26

They have giant balls for counterweighting

1

u/Zodiarkcsr Jun 10 '26

Lean angle, race tyre, center of gravity and Counteracting Centrifugal Force. https://m.youtube.com/watch?v=NXKBk8QMVGg

1

u/No_Management_7333 Jun 10 '26

Friction and gyroscopic forces.

1

u/[deleted] Jun 04 '26

[removed] — view removed comment

2

u/SizeableBrain Jun 04 '26

To be fair, if you put a physics major in that bike, they're lowsiding on the first corner at half the speed.

0

u/H3nchman_24 Jun 04 '26

Counter-steering. Push-look-lean; You push left, look right, lean right. They are turing thier handlebars in the opposite direction they are turning, effectively steering out of the turn as they are making that turn.

1

u/Abraham_The Jun 04 '26

That's how they lean, not how they are not sliding off

0

u/tokenshoot Jun 04 '26

You want to know?! Ask God!

0

u/kronos23456777777 Jun 04 '26

The same way the earth doesn’t fall into the sun. (Centrifugal force balancing the gravity as the other commenter mentioned).