A Cars forum. AutoBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AutoBanter forum » Auto makers » BMW
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Snow Chains not allowed? WTF?



 
 
Thread Tools Display Modes
  #21  
Old January 5th 05, 06:02 PM
Harri Holopainen
external usenet poster
 
Posts: n/a
Default

wrote:
...
>So why is it that the car can accelerate *quicker* than it can brake?


because even non-AWD cars have four wheel brakes, so there is no
braking performance difference between RWD and AWD. there is a very
significant acceleration difference in favor of AWD though.

>--
>Rob Munach, PE
>Excel Engineering
>PO Box 1264
>Carrboro, NC 27510



Ads
  #22  
Old January 5th 05, 06:08 PM
Harri Holopainen
external usenet poster
 
Posts: n/a
Default

"Badger" > wrote:
...
>Personally, I doubt that snow tyres alone can give you the same grip and
>acceleration as in the summer, a bit of journalistic exaggeration there
>methinks. They will undoubtedly give more grip than a summer type tread
>pattern would in the snow though.


the difference between a summer tyre and a proper snow tyre (not M+S)
on snow is very significant in practice. much more than ever could be
deducted by looking at the tyre patterns - the rubber compound is
quite different too.

of course an emergency braking will never be the same on snow, but for
normal driving the difference can be quite small. and that is the
potentially dangerous bit.

>>>

>> So why is it that the car can accelerate *quicker* than it can brake?
>>

>All things being equal Rob, it can't. The grip required to accelerate a body
>is the same to decelerate it. Mr Newton once said "a body in motion shall
>remain so unless acted upon by an external force", the same applies to a
>body at rest. In theory, air resistance should help it to slow at a greater
>rate than it accelerated, but it's such a small effect at sensible snowy
>weather roadspeeds that it's not really worth considering.
>What is an issue however, is the tread of the snow tyres. Some are
>directional, giving more bite when accelerating than braking. Personally, if
>it weren't for the silly laws in britain I'd fit them backwards so that the
>braking grip was better.
>Badger.
>
>



  #23  
Old January 5th 05, 06:10 PM
Harri Holopainen
external usenet poster
 
Posts: n/a
Default

"Oldun" > wrote:
>Could it be that BMW say do not use snow chains because of possible damage
>to the car. With limited clearance between the wheel and the underside of
>the wheel arch, the extra dimension could be critical at maximum spring
>compression. Particularly when the front wheels are on full lock.


that'd make sense. I'm pretty certain that there's not much extra room
between the wheel and the surroundings even without silly 18''
wheels.

>Just a thought.
>
>Oldun
>
>



 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
'05 S4 Cabriolet in the snow Ramzi Nassar Audi 3 December 30th 04 08:23 AM
Second set of wheels for snow tires ? Allroad 03 Audi 3 December 21st 04 01:50 AM
Snow Tires for a '98 740iL Rob Kos BMW 2 November 1st 04 03:50 PM
Snow tire recommendations for 1997 M3 sedan? Robert La Ferla BMW 3 October 17th 04 02:18 PM
Snow Chains in Audi A6 Quattro Ascot Audi 13 July 24th 04 05:35 PM


All times are GMT +1. The time now is 12:58 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AutoBanter.
The comments are property of their posters.