stopping distance

[sean sherry]

I read that the Peugeot 308 had the best stopping distance in a test of the best and the worst. Range Rover not so good. But I have always believed that the Tries stop a Car and that the Brakes only slow the wheels down.
The Peugeot's sister ..the Coupe did not match the Sedan.... it had different Tires !

 

[c107]

I read that the Peugeot 308 had the best stopping distance in a test of the best and the worst. Range Rover not so good. But I have always believed that the Tries stop a Car and that the Brakes only slow the wheels down.
The Peugeot's sister ..the Coupe did not match the Sedan.... it had different Tires !

Its not surprising that a big heavy car like the rangie stops slower. Obviously you can put on bigger brakes, but an extra tonne of weight is going to play a factor no matter what you do.

 

[sean sherry]

Surly Bryce heavier Cars /mini Trucks should be fitted with larger wider Tires to compensate ????....... And aren't they ?

 

[c107]

Surly Bryce heavier Cars /mini Trucks should be fitted with larger wider Tires to compensate ????....... And aren't they ?

I'm sure they are, but from my very rough recollection of high school physics mass is a pretty important factor in these sort of calculations.

 

[Patrick_R]

Sean,
Bryce is correct, without the mass the wheels/ tyres would just lock up with a good braking system, and just destroy the tyres, regardless of how good their grip.
One of our heavy trucks can have a mass of over 200 tonnes loaded.
However they can have 36 sets of brakes with exceptionally big tyres keeping it all in contact with the road.
Truck brakes, are very similar to cars, they can either be disc or drum.





On the other hand we can compare a Boeing 737-800 which only has 6 sets of wheels/brakes, but has a weight of roughly 90 tones on take off

However the brakes are vastly different to cope with the weight, and the stopping distances required for the ground speed involved.







Sean, you will recognise these brakes as they are identical in construction to auto transmission clutch packs, except the are open during normal conditions not closed as they would be in an auto.

What is important here, is the multiplication of surface area, over so many friction plates and discs compared with a single set of shoes or a single disc per wheel on a truck.

 

[sean sherry]

Very interesting pictures Patrick , and I take your point Bryce.....The Laws of Physics rule supreme.

 

[Michel]

Great explanation and breakdown of facts Patrick.
Many thanks for the pics.

 

[Patrick_R]

Love a good braking system Michel

 

[c107]

Those are really interesting pictures of the aircraft brakes, I never knew they were like that.

 

[Patrick_R]

Aircraft systems are very interesting Bryce.