Swapped My Tyres Round

[SMW]

OK this is really weird.

On my car I had 2 Dunlop 2000 on the front – same tread and wear. On the rear was another Dunlop 2000 and 1 Dunlop 9000 with a different tread pattern. The spare is also a brand new Dunlop 9000. The 9000 tread is the 'arrow rotation' type and I have kept them n/s o/s as appropiate to tread pattern.

To try and even things up I put the spare 9000 and the other from the rear on the front and 2 2000’s on the back – thinking it’s best to have the same tread patterns on each axle (?). The worst of the 2000’s became my spare. THE CAR AND STEERING WHEEL PULLED VERY SLIGHTLY TO THE RIGHT.

So I swapped them over – put the 9000’s on the rear axle and the 2000’s on the front - THE CAR AND STEERING WHEEL PULLED VERY SLIGHTLY TO THE LEFT.

Just to convince myself I wasn’t going mad I returned it to the original configuration , 2 X 2000’s on the front, and 1 X 2000 and 1 X 9000 on the rear and it GOES DEAD STRAIGHT.

BTW – pressures OK all round and tracking checked and OK. Only thing not done in that region is rebalance of the wheels.

So . . . can you mix tread patterns on the same axle and any idea why it pulls when the same treads are together ?

[bbear]

I'm gonna make a guess here, since you didn't say how many miles (or how worn) the 9000 is that was originally on the rear. My guess is that you are mixing a brand new tire (9000 from spare) with a used tire on the same axle. This causes an imbalance and in general is not a good thing to do. Reults as you documented are why.