Brake questions

[noel-pilot]

In the news item on the cliosport homepage there was an article earlier in the week via I think the pistonheads?? page reference brakes. Supposedly written by an ex copper.

One bit said that if you had a 1966 (or whatever) morris minor and a modern car travelling at the same speed bumpers level say 60mph and they both applied the brakes at the same time then they would stop in exactly the same distance???!!!!!

Is this right? I cant understand how a bag of sh!t forty year old car could stop as quick as say a brand new top notch ferrari, porsche, aston martin etc etc

he went on to say that the better brakes would only affect how hard you had to press the pedal not how far it took you to stop?

ideas and opinions please everyone!!

 

[Daz]

Erm, Id not agree..

After seeing Yozza going from a certain speed to 0.. I can safely say, it will out-brake most things, heh.

 

[fUbAr]

erm... i think the same braking principle works on Mountain Bikes too.... ive got a 205mm hydraulic disk up front on my bike and my mate has a 165mm disk on his and i can stop loads quicker than he can. Same should apply to cars i guess!

 

[noel-pilot]

Now thats what I would think! did anyone else see this article??! i dont understand how it can be true yet i cant understand why they would publish it!!!

 

[Daz]

Well,

Youre talking about it, wondering how it can be true.. now, Im going to look on their website to find the article.

Good Advertising tekniq!

 

[noel-pilot]

thats what i just did and its not in their news section??!!

 

[noel-pilot]

found it heres the link

http://www.pistonheads.com/doc.asp?c=109&i=8341http://www.pistonheads.com/doc.asp?c=109&i=8341

heres the paragraph i meant

Providing your brakes are in good working condition, the amount of time and distance it takes your car to stop from any given speed is all down to the friction properties of the road surface and the ability of your tyres to grip it.

Lets look at an example. You are driving a good quality modern saloon car (without ABS) along a motorway at 70 mph in lane two. Next to you, in lane one, there is a 1966 Morris Minor 1000 travelling at exactly the same speed. An unexpected incident occurs and the drivers’ of both cars stamp on their respective brake pedals - at exactly the same point and lock their wheels of both cars into a skid. Remember, this is at the same time and at the same point along the road with the front bumpers level. The result is that both cars WILL skid to a stop over the same amount of distance as each other - fact!

 

[Deeg]

I think that he means if they skid then they will stop at the same time, but skidding isnt stopping. You dont slow down if you skid (or at least not much).

If you have ABS, with up-rated brakes and good tyres, and in good conditions, you will stop a lot quicker than in another car.

I would also imagine that weight would come into it, but not sure how, but would have thought i lighter car would be easier to stop.

I drove a rally spec EVO V, and it went from 80 - 10 in a seconds (and back up in an equally short time), much quicker than i would have been able to do in a 1.2.

But as you say, surely advancements in technology should have reduced the stopping distances, which is some peoples arguments for the increasement of speed limits.

 

[noel-pilot]

hmmm his article is all about stopping without ABS without skidding using braking control etc, i can understand what he says about being able to stop quicker without abs, if you practice its posisble by balancing just on the edge of when the abs kicks in, and you can stop quicker, so i think he is saying if you brake as hard as possible without skidding. im now thinking he is completely wrong OR there is something that we are not getting!!!


i cant understand how he could possibly be right tho! i mean rally spec evo vs aston martin vanquish vs 1960s morris minor!!!!

 

[Lunner]

yeah exactly, think someone has interpreted the artical wrong, when skidding, it had nothing to do wiht how good your brakes are, as they are effictivly just holding the wheel, what i think does apply, is the quality of rubber you have on there. Obvously a morris minor wont be running eagle F1s etc, and so will take further to stop

 

[noel-pilot]

but he seems to be saying that WITHOUT skidding they will take the same amount of distance to stop!! or am i just really thick?!!!

 

[Lunner]

at exactly the same point and lock their wheels of both cars into a skid. Remember, this is at the same time and at the same point along the road with the front bumpers level. The result is that both cars WILL skid to a stop over the same amount of distance as each other - fact!

Your just really thick - no offense!

 

[noel-pilot]

hehehe cheers mate!!! been a few days since I read it and obviously didnt read it very well!!!

still not sure about the whole same distance cos a modern car should hgave better tyres!!!

anyways has kept us all marginally entertained for the last 20 mins!!!

 

[Lunner]

lol, true, true

 

[AJR93RT]

Surely this article does totally depend on the weight of the two cars in question. As a lighter car travelling at a the same speed will have less momentum and therefore with the same tyres and road coefficent of friction and locked wheels the lighter car will stop in a smaller distance. In this case im sure this would be the morris minor. Also being able to stop in a smaller distance without ABS would be very close to impossible. As the ABS system cycles the braking force applied to the wheels at a very fast speed and keeps the wheels very close to locking. If u could manage to brake and hold the braking force as close as possible to a locked wheel without locking it, its true u would stop in a shorter distance although it would be very hard to do. Think this makes sense

 

[RobFenn]

Read the comments on the article, rather than accepting one side of a (mis-guided) arguement.

-Rob