i think maybe some good tyres ( i'm currently rocking cheapies and all 4 are of different brands:/) and bigger/wider alloys?
i'm only on 14s at the moment...
im not sure, but it makes it steer to the left slightly when it does lock up... nothing too extreme though.only happened on a few occasions though, could just be my rough driving.
if its the rears locking up, it could be a load apportioning valve problem
i always test mine by hitting the brakes on a loose surface and checking the length of the 4 skidmarks
My K11 used to do it all the time! Put a set of decent tyres on it and it was fine! Also cleaned the brakes up a bit coz they were binding on slightly!