[Mgs] Tires (or lack of same)

[Paul Hunt]

That certainly shouldn't be the case in any car.  The front and rear brake
forces are designed to prevent that happening precisely because of the weight
transfer under braking, either by having a proportioning valve like when it
was drums all round, or by selecting the relative sizes of rear slaves and
front slaves or calipers like on the MGB.  Some French cars have a variable
proportioning valve controlled by the suspension height difference, front to
rear.  The end result is that you can only have a relatively small proportion
of the braking effort on the rear with four-wheel brakes, which is why the
concept of a handbrake or parking brake being an 'emergency' brake is
ridiculous, the phrase 'merely impeding progress' comes to mind.  The GT
(except V8) has larger bore slave cylinders as with the extra weight it can
take more rear brake force before locking than can the roadster.  If you get
rear locking on any car something is wrong, i.e. a silly mix of tyres,
contaminated pads/discs, defective calipers etc.  Lock the rears at any time
and the rear of the car is very likely to swing one way or the other.
Incidentally if you bang on the brakes you will lock the fronts much more
easily than if you use progressive braking which allows some weight transfer
to occur before applying the brakes harder.  And gradually releasing the
brakes as you come to a stop avoids the jerk at the end ...

PaulH.
  ----- Original Message -----


  The thing about braking is that in front-engined pre-ABS cars, the rear
  tires will lock up before the fronts under hard braking