Ive got a little problem with the size of my calipers. Im currently running on Astra 16v old stylee calipers (biggest ones) and Black Diamond discs. I tried fitting 6.5x16" Speedlines at the weekend and one of the front wheels just locked up when i tried to pull away. One of the calipers had rubbed against the alloy and would not turn when off the floor. I've been told the calipers are two big and that the way around it is to fit GSi calipers form an Astra or Cav. Does this sound right ? If so has anyone got any for sale ?