Rear brake judder

[mrfixit]

Just a bit of info getting ready for mot, i put two new tyres on two back wheels and moved them to the front, and the front wheels on the back i had a really bad judder on braking, so two new tyres on the back and its totally gone, seems it didnt like front wheels put on the back even though they where good and balanced.

[Aardvark]

Other people have had this same result. Most puzzling.