Pages: [1]   Go Down

AuthorTopic: maths  (Read 3619 times)

0 Members and 1 Guest are viewing this topic.

Offline lambert

  • Moderator
  • ***
  • Posts: 2137
  • Attack: 100
    Defense: 100
    Attack Member
  • Karma: +1/-0
  • and then as if by magic
    • harrogate
  • Referrals: 0
maths
« on: December 15, 2011, 07:19:02 »
Hi clever peeps,

Whilst I was getting my tracking done yesterday I was reading a poster from michelin that was telling me how many miles of sideways a tyre feels per rotations per mile when the tracking is off. It did not however give the formula so I could do it for my tyres.

So can anyone tell me how to work it out.

Cheers.
Logged
Lambert Coverdale.

As slow as possible, as fast as necessary.

Two and a half litres of turbocharged diesel goodness.

Offline dxmedia

  • Posts: 1355
  • Attack: 100
    Defense: 100
    Attack Member
  • Karma: +2/-2
  • Referrals: 0
Re: maths
« Reply #1 on: December 15, 2011, 08:19:08 »
It was on the poster I was reading the tyre place yesterday ;)

If your aliment is out buy say 3mm and the tyre is a 29" - it rotates something like 950 times every mile (simple to work out accurately) and multiply 950 x 0.003 to get how many meters of scrub per mile.

It's a bull [!Expletive Deleted!] calculation though. It's presuming that the whole tyre is moving sideways which it isn't. If the car only traveled in a dead straight line then one side of the tyre would be effected by this, but you move the tyre around on the road which will effect this. It's a case of use shocking (ly bad) maths to scare people.
Logged
1959 Unimog 404 DoKa i6
1996 Jeep ZG i6with 6" suspension lift
1999 2.5 v6 Omega autobahn stormer
2001 1.4 Polo

Offline LandRoger

  • Regional Rep
  • *
  • Posts: 1759
  • Attack: 100
    Defense: 100
    Attack Member
  • Karma: +1/-0
    • Salisbury Plain Wilts.
  • Referrals: 0
Re: maths
« Reply #2 on: December 15, 2011, 16:35:01 »
There is an easy way over this useless information ,dont read makers blurb there is no better indication of wear than the human eye so when you see wear change the wheels around and if its the tyre edge thats worn then have the tracking done,simples!
Logged
K.I.S.S. Keep It  Simple Stupid          
I am not a complete IDIOT !! have no right thumb,
1961.Series 2 v8  + 03 Vitara SWB.
MG Midget 2,0L Pinto 1973  (swifty).

Offline tack43

  • Posts: 351
  • Attack: 100
    Defense: 100
    Attack Member
  • Karma: +0/-0
    • Worcs, Redditch
  • Referrals: 0
Re: maths
« Reply #3 on: December 15, 2011, 21:03:06 »
Is this like tyre manufacturers insisting we NEED winter tyres?
Logged
Rich

1985 90 300TDI "Defender" SOLD.
1990 RRC 3.9 Vogue LPG
1991 RRC 3.9 Vogue SE "The spare parts box!" Broken for spares
1993 RRC Off-roader. No engine. Yet!
1991 RRC 3.9 Vogue SE "Tempory off-roader" Failed MOT - More spare parts
1992 RRC 3.9 Vogue SE "New tempory off-roader" SOLD

Offline lambert

  • Moderator
  • ***
  • Posts: 2137
  • Attack: 100
    Defense: 100
    Attack Member
  • Karma: +1/-0
  • and then as if by magic
    • harrogate
  • Referrals: 0
Re: maths
« Reply #4 on: December 16, 2011, 06:24:36 »
I think that is down to people mistaking grip for handling and then needing over wide tyres to feel in control of their car. What that means is that they then can't see how those same tyres don't work properly in winter and they need to be force sold the right tyres to keep the rest of us safe.
Logged
Lambert Coverdale.

As slow as possible, as fast as necessary.

Two and a half litres of turbocharged diesel goodness.

Offline Range Rover Blues

  • Moderator
  • ***
  • Posts: 15218
  • Attack: 100
    Defense: 100
    Attack Member
  • Karma: +3/-0
    • South Yorkshire
  • Referrals: 0
Re: maths
« Reply #5 on: December 19, 2011, 01:39:22 »
Tyres only generate sideways force when they are slipping anyway, so every corner you drive rund the tyres are not going "straight on", the lateral force is proportional to what's called the slip angle.
Logged
Blue,  1988  Range Rover 3.5 EFi with plenty of toys bolted on
Chuggaboom, 1995 Range Rover Classic
1995 Range Rover Classic Vogue LSE with 5 big sticks of Blackpool rock under the bonnet.

Offline dxmedia

  • Posts: 1355
  • Attack: 100
    Defense: 100
    Attack Member
  • Karma: +2/-2
  • Referrals: 0
Re: maths
« Reply #6 on: December 20, 2011, 11:52:32 »
Seems to also neglect to mention tow in / out as well.

OK permi 4x4's should be 0, but nothing else.
Logged
1959 Unimog 404 DoKa i6
1996 Jeep ZG i6with 6" suspension lift
1999 2.5 v6 Omega autobahn stormer
2001 1.4 Polo

Offline Range Rover Blues

  • Moderator
  • ***
  • Posts: 15218
  • Attack: 100
    Defense: 100
    Attack Member
  • Karma: +3/-0
    • South Yorkshire
  • Referrals: 0
Re: maths
« Reply #7 on: December 27, 2011, 03:35:50 »
zero to 3 degrees negative on a LR.  I always used to get p***ed off when tyre fitters tried to set my old RWD Escort to toe out, becuase the wall chart said so, even when the wall chart said it was for a 1980s Escort, they just don't understand some of them.
Logged
Blue,  1988  Range Rover 3.5 EFi with plenty of toys bolted on
Chuggaboom, 1995 Range Rover Classic
1995 Range Rover Classic Vogue LSE with 5 big sticks of Blackpool rock under the bonnet.
Pages: [1]   Go Up
 





SimplePortal 2.3.5 © 2008-2012, SimplePortal