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Author Topic: Why do office chairs have five wheels?  (Read 12800 times)

Offline turnipsock

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Why do office chairs have five wheels?
« on: 27/05/2009 19:56:13 »
Why do office chair always have five wheels?



I'm fed up banging my heels.


 

Offline lightarrow

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Why do office chairs have five wheels?
« Reply #1 on: 27/05/2009 20:35:32 »
Why do office chair always have five wheels?
I'm fed up banging my heels.

What is it? A word play?   :)

I venture a guess: 3 or 4 wheels would not be enough to prevent it to overturn under the sitter's weight when displaced over the space bewtween two wheels (personal experience  ;)).

More than 5 would be more expensive and so meaningless.
« Last Edit: 27/05/2009 20:37:27 by lightarrow »
 

Offline Chemistry4me

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Why do office chairs have five wheels?
« Reply #2 on: 27/05/2009 20:52:14 »
Ha! I didn't even notice I was sitting on one all this time! With five wheels you can put your feet on two of them, with only four it is a bit of a struggle.
 

Offline turnipsock

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Why do office chairs have five wheels?
« Reply #3 on: 27/05/2009 23:31:08 »
...but old office chairs had four legs.



and I seem to remember we had one that had three legs, sure the legs stick out a bit more but why settle on five?

 

Offline JnA

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Why do office chairs have five wheels?
« Reply #4 on: 28/05/2009 05:08:58 »
Probably because five is the number that dictates what is safe (on a number of surfaces) and cost effective.
 

Offline lightarrow

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Why do office chairs have five wheels?
« Reply #5 on: 28/05/2009 08:06:56 »
To have a safe chair with four wheels (and you don't have to go back many years, just ~ 10) you have to make it too heavy.
 

Offline Steph

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Why do office chairs have five wheels?
« Reply #6 on: 28/05/2009 10:50:43 »
I'd opt for safety. My first office chair was a 3-wheeler, and it was always falling over. Sometimes with me on it  :-\ You just can't safely spin around in circles on 3 wheels...
 

Offline Chemistry4me

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Why do office chairs have five wheels?
« Reply #7 on: 28/05/2009 11:03:48 »
Or if you're having a race with your friend who happens to have five wheels.
Still, five wheels = more resistance right? ;D
 

Offline Don_1

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Why do office chairs have five wheels?
« Reply #8 on: 28/05/2009 11:40:36 »
I blame decimalisation.

5 Wheels on my office chair,
And I'm still rolling along.
Those chairs and keys,
Don't bother me.
My printer's bust,
Smothered in dust,
But I'm still rolling along,

4 Wheels on my office chair,
And I'm still rolling along.
Those DVDs,
Don't bother me.
CD's cracked,
I'm feeling whacked,
But I'm still rolling along.

3 Wheels on my office chair,
And still rolling along.
My screen has froze,
I'm beginning to doze.
Serial bus,
Covered in puss.
But I'm still rolling along.

2 Wheels on my office chair,
And I'm still rolling along.
My optical mouse,
Has caught a louse.
Connection down,
Hub not found.
But I'm still rolling along.

1 Wheel on my office chair,
And I'm still rolling along.
My hard drive,
Just took a dive.
File not found,
It's gone to ground.
But I'm still rolling along.

No wheels on my office chair,
So I'm not rolling along.
The central pole,
Shot up my a***hole.
No more smiles,
Now I've got piles.
And I've stopped rolling along.
 

Offline Bored chemist

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Why do office chairs have five wheels?
« Reply #9 on: 28/05/2009 18:49:37 »
Thanks for that, best giggle I have had in a while.
 

Offline LeeE

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Why do office chairs have five wheels?
« Reply #10 on: 29/05/2009 16:34:34 »
Wheeled chairs have a minimum of five wheels for safety reasons.  Because the chair is on wheels it is assumed that people will 'scoot' on them (for short distances) rather than get up and walk, but because the 'scooting' force is applied sideways, to the end of a long arm, the force tends to topple the chair as much as it propels it.  While the wheels are on a smooth surface there are few problems but if someone hits a ridge in the floor, such a rug or a raised floor vent, the chair is much more likely to topple than roll.  This is made even worse by the fact that the wheeled base can rotate freely, so once one wheel has struck a ridge and stopped, the wheeled base is likely to rotate until a second wheel hits the ridge and when this happens the effective wheelbase is no longer twice the arm length but only sin/cos 45 deg of the wheelbase i.e. it is reduced by a factor of 0.7071067.  Increasing the number of wheeled arms on the base mitigates against this.
 

lyner

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Why do office chairs have five wheels?
« Reply #11 on: 31/05/2009 16:25:32 »
Turnipsock
I'm sure you can afford an upgrade!
 

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Why do office chairs have five wheels?
« Reply #11 on: 31/05/2009 16:25:32 »

 

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