Haha that's brilliant! I don't know how much that last one weighs, but I don't think I'd be too happy to see that, were I a ski jumper!

the heavy machinery tire weighs 220kg (about 500 lbs)

i love these videos. this show nees to come to the US, dramatic music and all.

As soon as I saw the heavy machinery tire, I couldn't help but thinking, "that's a bad idea." Turns out I was right! Good thing no one got hurt.

This show rules. So dramatic!

Oh, how they turn the most mundane things into wild entertainment, those Japanese.
It's a rare gift.

So distance is a function of radius?

Here's Japanese Gladiators! Go back to sleep America!

special_ops: A Matrix Reloaded song too!

The distance is more a function of mass, than of radius. The heavy machinery tire would have traveled much further had it not destroyed the end portion of the ramp.

MINK- LOL. What is that a reference to, anyway? I heard it in a techno track- "Go back to sleep america. Here's american gladiators. Shut up! Your government is in control"

I'm not sure that is is all a function of mass over radius is it? I mean that F1 tire must weigh more than the light car tire doesn't it?

Don't forget about friction. Wider tires get a bigger penalty. That's the reason F1 tire did so poorly. Radius affects acceleration rate but not terminal velocity (well maybe a little due to a larger cross section). The best bet would be a heavy, thin tire.

Very funny. I'd like to see those guys work with the mythbusters. I'd also like to see a tire with a person inside go down the ramp-- but I think that would be a different show.

I heard it in a techno track- "Go back to sleep america. Here's american gladiators. Shut up! Your government is in control"

I think bloodymario hit on it. It's mass, width, radius and tread pattern. Heavy mass, narrow width and a medium radius will win out over a heavy mass, medium radius and wide tire all the time.
I wonder if the ramp at the end was official or not. It sure didn't look like it. I'd hate to send world class athletes off of some piece of shit ramp I put together in the garage over the weekend.:)

Ok, quick physics lesson time. 

There are three forces acting on the tire as it moves: gravity, air resistance, and the reaction force of the ramp on the tire. (Or tyre if you lean more towards the British persuasion.)

Gravity is the same for each of the tires -- as Galileo proved when he dropped two balls of different masses off of the Leaning Tower of Pisa and they landed at the same instant. But that doesn't mean that the tires reach the same speed by the end of the ramp, because they each have a different moment of inertia.

The higher the moment of inertia, the slower the tire builds angular momentum, and the lower its velocity when it leaves the ramp. And moment of inertia is a product of mass, and radius squared -- so for a given weight of tire, it would go faster if it has a smaller radius.

The air resistance depends on the tire's surface area. The larger the frontal area, the more drag it will experience. And the lighter the tire is, the more the force of drag will slow it down.

So the tire (or tyre) that gets farthest is the one that has the best balance of: large mass, small moment of inertia, and low frontal area.

Friction and tread pattern have negligible effect, since the tires are rolling, not sliding.

Another thing I just thought of is that they probably didn't all come off of the ramp at the same angle. If they caught a good bounce and got more height, that would make a big difference as well.

How's that for a geek posting? 

you also have to take into account the rigidity of the tire, because a more rigid tire will maintain more of its forward velocity. a tire that flexes on impact will absorb a lot of that momentum both horizontally and vertically.

i would argue that tread pattern does have an effect on their speed when they hit the ramp, due simply to friction. although negligible at first glance, i would think that a 'slick' tire would be a lot slower than a tire with an aggressive tread pattern. i bet if you put twin tires up there, and put snow studs on one of them, the studded tire would beat out the 'control' tire by full seconds.

Considering this is Japanese TV, I'm surprised they didn't have someone in a skin-tight shiny spandex bodysuit and a bicycle helmet inside the truck tire. Giving a thumbs up and a huge goofy grin right before being pushed off the lip.

pho3n1x, I definitely agree about rigidity. Not sure what you mean about friction, if anything the tread might add slightly to the tire's rolling resistance but I can't imagine it being significant. Other things being equal, the friction between tire and ramp would be identical for treads vs. slicks unless water is present -- contact area cancels out when calculating frictional forces.

lol@Carnifex0

The rigidity is important to a certain limited extent. A tire that is ideally rigid will flex at the beginning of the ramp, then snap back to it's normal shape right at the end, adding an extra elastic force to push it up from the jump. A tire that is too rigid will not take advantage of this, and one that is too elastic will not recover enough of it's original shape to take full advantage of the ramp's incline.

In the same way, where a correctly weighted tire will force the ramp down and then back up in time to add a lifting force to it's launch, too massive of a tire will push the ramp too hard, so it really depends arbitrarily on the construction of the kick ramp.

Other than the rigidity, the grip of the tire on the green will affect how much of the initial potential energy is retained for jump speed. You'll notice how some of the tires grip the launch ramp pretty well, while others begin bouncing and skidding down? The ones that begin to skid don't pick up as much speed as the others, and consequently don't fly as far.

Next to the rigidity affecting grip and launch angle, and tread affecting grip, it seemed like air resistance was negligible. Though the heavy machinery tire would have been the only one considerably less influenced by air resistance, it didn't count because it literally destroyed any experiment.

It's fun to think about what is affecting these, but still isn't the real point of the whole thing to see some big wheels fly high up in the air and then come crashing down!?

It's dead! And I don't think I have the authority to do something about it!

*dead

Edit: Nope, sure don't.

Gold Star invocations (dead) cannot be executed by Abel_Prisc because Abel_Prisc is not a Gold Star member - sorry.

fixed...

re friction and tread pattern; imagine if you will, a tire with two 3-inch-tall ridges running parallel to eachother, about the thickness of an ice-skate, along the circumference of the tire. similar to how diecast toy cars have that single ridge on the plastic tire. wouldn't this serve to reduce friction during the roll, and thus increase either the potential distance before the tire comes to a stop, or to increase the acceleration of the tire during the downhill roll?

Friction during the downhill roll is what provides the horizonal momentum. The tire begins with a certain amount of potential energy from it's height, and when it falls this energy is transformed into momentum. You use a continuously curved ramp to try to get as much of that momentum to approach a near-45 degree angle as you can. Eliminating friction from the tire-slope contact would be like dropping a tire on a small 45-degree plate. You might as well just bounce it off of your roof and see how far it 'flies.'

Thanks, Plastiqmonkey. I was depressed when I couldn't watch what everyone else seemed to have so much fun watching.

The whole friction thing is confusing because its effects are counter-intuitive. In fact, if there was no friction at all, the tire would launch the fastest. Here's why.

There's a certain amount of potential energy available, due to the height of the ramp. As the tire rolls down the ramp, that potential energy is converted into both linear momentum and angular momentum. The more angular momentum the tire builds, the less linear momentum it will have at launch. Since the tire's spin does nothing for its landing distance, the energy that goes into angular momentum takes away from the tire's results.

If the ramp was covered in slick ice and the tire slid down the ramp without spinning at all, that would give it the highest takeoff speed, because none of the potential energy would be converted to angular rotation. The fact that there is friction means that a lot of the potential energy goes into making the tire spin instead of making it go fast.

The actual value of friction forces for each tire is completely independent of its tread pattern. Even pho3n1x's scenario of the two narrow ridges would give the exact same friction forces as a wide flat tire. This is another thing that is counter-intuitive, but it's fairly easy to understand: the pressure of the tire on the ramp is its weight divided by the contact area; the friction forces are proportional the pressure times the contact area. The contact area cancels out.

The only reason tires have treads is to channel water away when roads are wet. Treadless tires actually wear out more slowly than tires with treads, which is why race cars run on slicks when the track is dry, but switch to treads if it starts raining.

Anyway, as statueofmike says, it's really all about watching crazy Japanese TV launching tires off of a ramp. Though it's fun to turn it into Physics 101 as well! 

wow yeah... okay i totally forgot about the fact that the weight of the tire would be distributed differently on 'ice-skate tread' than normal tread, effectively cancelling out the difference in contact area. good call.

turning things like dropping tires on a ramp into science is the whole reason these crazy japanese shows rock. it's fun as hell, and yet there's still an element of higher education to it, should you choose to see it.

imagine the physics lesson on the 'cats stealing fish' show... heh

Good lord, don't even go there!

So, you're saying that I'm imagining things when I feel my bicycle going faster and with less effort when I replace my knobby off-road tires with road slicks?

20 years ago - "That one was cool but imagine if we had a bigger tire."

Up vote for 'stuff I wanted to try when I was a kid'.

messenger, you're absolutely right about knobbly tires, in which case you're talking about them having a higher rolling resistance. That may also be a factor with these tires, but I don't really believe it would amount to anything compared to the other forces involved.

Ok, I'm hanging up the physicist hat now!

Totally entertaining. Worst scientific method ever. GET A DECENT RAMP AND RUN THE HUGE TIRE AGAIN DANGIT! It's no secret that it'd dominate the rest by a landslide. And I'd love to see a monster-truck tire as well.
Also.
Arvana is entirely correct that the experiment is totally pointless due to the fact that friction is removed from the equation. Who cares if their tires roll down a hill fast? What we want to know is how well they perform in a REAL freakin situation. Fun as it was, you can expect that if you roll an enormous tire down a hill, it will "jump" really freaking far off a ramp due to its tremendous momentum. However an extremely efficient, light tire will fly a lame distance. hmm....

...so i'd say this video gives us another fun demonstration of Newtonian physics, but doesn't help us at all when it comes to buying the right tires for our Car/Truck/RiceRocket/IndyCar/SpaceShip/Etc.

"Ok, I'm hanging up the physicist hat now!" -arvana

Don't give up now chief. It's true that knobby tires are slower on a smooth road, but smooth tires are slower on a knobby road. AND you were right in saying that that point is moot in this experiment since friction (excluding static friction which is immeasurably small in this experiment and therefore moot as well) is removed entirely, allowing MOMENTUM to rule.

*asia

*wheels

Adding video to channels (Wheels) - requested by firefly.

Being a Finn I do watch a certain amount of ski jumping, and no, that ramp at the end isn't there when people jump. It's probably just there to "simulate" the jumping motion of a ski jumper (infact, I think they explain that in the video).

I do think rolling resistance does play a part in all this, just not sure how big a part. The F1 tyre is slightly heavier (longer jump), has a slightly smaller radius (longer jump, according to arvana) than the sports car tyre, and jumps the shortest. What I know of F1 tyres is that they are very very sticky and have very poor rolling resistance (that is "lots of it"). Also of course it's way wider and hence has more drag, but that isn't enough to explain the difference. So yeah, I think we need more testing. I live only a few kilometers from the Puijo K-120 hill (also has two smaller ones) and am going to find out what it would take to get them to let me try this. =)

But what we really need is someone trying this on the mother of all ski jumping hills, the Planica (K-185, record 239+m, Ahonen jumped even longer but couldn't stay up) with a sturdy ramp that can take on the 220kg tyre. Also we need rocket boosters to get the speed up and over 200kmh. =)

*promote, why not?

Promoting this video back to the front page; last published Monday, July 9th, 2007 11:29am PDT - promote requested by Fusionaut.

*dead

This video has been declared non-functional; embed code must be fixed within 2 days or it will be sent to the dead pool - declared dead by blutruth.

Awarding Mordhaus with one Power Point for fixing this video's dead embed code.

*backup=[...snipped...]

Added alternate embed code for this video - backup requested by Zawash.

*length=6:14
Excellent stuff!

The duration of this video has been updated from unknown to 6:14 - length declared by Zawash.

..And forgot: *wtf!

Adding video to channels (Wtf) - requested by Zawash.