I had to cart my mtb round in a car yesterday and today so I took the wheels off. Overnight I left the bike upside down in the hallway (I know, not recommended due to risk of oil leaks). Anyway - no oil leaks but the brake pads were pushed so tight together this morning that I couldn't get the disk in between them. Anyone know what caused this and whether the bike being upside down had anything to do with it? Is there an easy cure? I did manage to ease the pads apart eventually with a screwdriver but they are still quite tight against the disk.