Date: Fri, 13 Jan 2006 21:15:37 GMT From: Johannes H Andersen <johsnospamfitter.com> Subject: Re: New tyres fitted to rear?
Al wrote: > > Just had two new tyres fitted to my 1987 900 Aero. > > Costco insisted that the new tyres were fitted to the rear not the front, > apparently they have been told by Michelin not to carry out customers wishes > and fit newer tyres to the front. They were playing a "police" video which > demonstrated the "problem" i.e. more grip on the new front tyres leads to > the car oversteer and skidding/spinning. I have heard this explanation, but it is also a bit of a mystery to me. If braking in the wet depends on thread depth, then you get the shortest braking distance when the new tyres are fitted at the front. The instability problem must be an extreme case with worn out rear tyres and a very front heavy car. In practical terms, new tyres are always better than old tyres; they degrade in a linear fashion from 8mm and down to 1.6mm or whatever. Since we can't afford to change tyres as often as a F1 racing team, we must adjust our driving to the current state the tyres.