Is the video of Saudis changing wheels on a moving car fake?

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Discussion Overview

The discussion centers around the authenticity of a video showing individuals changing the wheels of a moving car that is balanced on two wheels. Participants explore the mechanics involved, particularly focusing on the role of differentials in automotive engineering and whether the scenario depicted is feasible or staged.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Exploratory

Main Points Raised

  • Some participants question whether a standard friction clutch differential would allow one wheel to remain stationary while the other is in motion, suggesting that this contradicts the differential's function.
  • Others propose that the car could be using a limited slip differential, which would theoretically allow both wheels to have equal power and velocity, but express skepticism about this possibility given the video evidence.
  • A participant argues that the differential is functioning correctly, asserting that an open differential combined with left foot braking could allow the wheel in the air to remain stationary while the other wheel receives power.
  • Some participants express doubt about the video's authenticity, with one hoping to expose what they perceive as bad journalism.
  • Another participant mentions having witnessed similar stunts in person, suggesting that the scenario may be plausible.
  • Several participants discuss the mechanics of locked versus open differentials, with some asserting that an open differential would not allow the wheel in the air to remain stationary, while others clarify that the stunt requires an open differential for the wheel change to occur.
  • There is mention of differential braking as a technique that could potentially be used to achieve the stunt, with references to separate controls for the brakes on each side of the vehicle.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the authenticity of the video or the mechanics involved. Multiple competing views remain regarding the type of differential that could allow the stunt to be performed, and whether the video is genuine or staged.

Contextual Notes

Participants express uncertainty about the specific mechanics of differentials and braking systems, and there are unresolved questions about the assumptions underlying their claims. The discussion reflects a variety of perspectives on automotive engineering principles without definitive conclusions.

RKD89
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People keep posting crazy videos about Saudis changing wheelsof a car when
the car is still moving , but is on two wheel
http://www.bbc.co.uk/news/world-middle-east-22664659

It can be seen in this video

Wouldn't a car's standard ( friction clutch one )differential not allow the wheel to remain stationary ( either the front wheel or rear wheel that is suspended in air has to move depending on whether the car is front wheel or rear wheel drive )

Isn't it the whole point of a friction clutch differential , that both wheels HAVE to have power/motion\

Please correct me if I am wrong , considering it's BBC who have put up this
 
Engineering news on Phys.org
What do you mean can you call BS on it? You can see it with your eyes.

EDIT: It's late and I may be talking crap, let me have a think. : /
 
Last edited:
Well , let me rephrase it
The Car would have some form of "limited slip differential" , which means both the raised wheel and the other wheel will be sort of forced to have equal power/velocity , wouldn't they
In the video , the raised wheel doesn't move ( hence they can change the tires ) , ie differential isn't doing it's job

So , my point is , either the car has some new form of differential ( I highly doubt ) or it's fake
 
Well for starters, it's not fake. So let's set our minds out to how it can be achieved.

The diff can't be locked in anyway, as the wheel would be spinning. So the diff must be open, however this would mean that power would be spun away. It also means that the wheel would be easy to lock with left foot braking.

So an open diff with left foot braking allows power to be transmitted to the wheel that has the inertia of the car dragging it along, whilst keeping the wheel in the air stationary.

:biggrin:
 
Last edited:
RKD89 said:
In the video , the raised wheel doesn't move, ie differential isn't doing it's job
The differential is actually 'doing it's job'.
Wikipedia® said:
In automobiles and other wheeled vehicles, a differential is the usual way to allow the driving roadwheels to rotate at different speeds.
http://en.wikipedia.org/wiki/Differential_(mechanical_device)





xxChrisxx said:
So an open diff with left foot braking allows power to be transmitted to the wheel that has the inertia of the car dragging it along, whilst keeping the wheel in the air stationary.

You got it... :approve:



OCR
 
Last edited by a moderator:
@Chirss
well that's possible
Thanks

PS: I was hoping the video was fake and I could expose BAD journalism
 
RKD89 said:
I was hoping the video was fake and I could expose BAD journalism

Just tune into Fox News; you'll have a lifetime supply to play with. :rolleyes:
 
Danger said:
Just tune into Fox News; you'll have a lifetime supply to play with. :rolleyes:

+1 on that :smile:
 
I've seen it done in person. Google james smith, he is a stunt man
 
  • #10
I'm just a car enthusiast and not an automotive engineer, but I don't see why it can't just have a limited slip (locked) differential. If the differential is open, then I am certain that the wheel in the air would spin and the wheel on the ground would get no power. Same situation as having one wheel on snow or in mud and the other wheel on dry asphalt - i.e. the entire point of a locked differential.
 
  • #11
afreiden said:
I'm just a car enthusiast and not an automotive engineer, but I don't see why it can't just have a limited slip (locked) differential. If the differential is open, then I am certain that the wheel in the air would spin and the wheel on the ground would get no power. Same situation as having one wheel on snow or in mud and the other wheel on dry asphalt - i.e. the entire point of a locked differential.

I'm not clear what your point is. Are you saying the video is a fake and the people who have seen it themselves are lying or the opposite?
 
  • #12
afreiden said:
I'm just a car enthusiast and not an automotive engineer, but I don't see why it can't just have a limited slip (locked) differential. If the differential is open, then I am certain that the wheel in the air would spin and the wheel on the ground would get no power. Same situation as having one wheel on snow or in mud and the other wheel on dry asphalt - i.e. the entire point of a locked differential.

If you just wanted to drive off on two wheels, you'd just weld the diff up and be away, merry as you like. You can't do that if you want to do the wheel change stunt as well, as it requires the wheel in the air to be not rotating.
 
  • #13
xxChrisxx said:
If you just wanted to drive off on two wheels, you'd just weld the diff up and be away, merry as you like. You can't do that if you want to do the wheel change stunt as well, as it requires the wheel in the air to be not rotating.

Right, because of the wheel change stunt in particular, they need the OPEN differential. I understand now. Still don't get the left foot braking thing you mentioned though.

phinds said:
I'm not clear what your point is. Are you saying the video is a fake and the people who have seen it themselves are lying or the opposite?

I just didn't understand the confusion, since it seemed obvious to me that you could drive crooked like that if you simply had a locked differential. Now that I re-read the OP and responses, I see what they were getting at. The wheels in the air are NOT rotating at the same speed as the wheels on the ground, weird.
 
  • #14
afreiden said:
Still don't get the left foot braking thing you mentioned though.
xxChrisxx said:
The diff can't be locked in anyway, as the wheel would be spinning. So the diff must be open, however this would mean that power would be spun away. It also means that the wheel would be easy to lock with left foot braking.

That might not have been the best description, so we'll try...

My bold...
The diff can't be locked in anyway, as all the wheels would be spinning. So the diff must be open, however this would mean that power to the right wheels would be spun away. It also means that the wheels would be easy to lock with [STRIKE]left foot[/STRIKE] right wheel braking.

Actually, it's called differential braking and works like this...
Differential braking depends on the asymmetric application of the brakes on the wheels. For this, the vehicle must be equipped with separate controls for the right and left brakes.
http://en.wikipedia.org/wiki/Differential_braking#Differential_braking

Can also be called independent wheel braking.

http://forums.off-road.com/jeep-short-wheelbase/4306-4-wheel-independent-brakes-poor-mans-locker.html#post21022


In any case, the people in the video had to stop the right side wheels from turning... although there are other ways, they probably have a separate system for the right and left side brakes.

And... they would probably use their left foot to push the brake control. (pedal)... :smile:



OCR
 
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  • #15
Hmm... those were called "cutting brakes" when I was a kid, and they were used only on dune buggies.
 

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