1) Bike has one punctured tube and one perished tyre (opposite wheels)
2) Replace both tyres with new, vaguely matched tyres and new tubes
3) Discover that the back, slightly nobblier wheel catches on the rear gear cable
4) Swear loudly
5) Swap tyres over, becoming rather suspicious of cheap ASDA inner tube.
6) Test bike
7) Wait 2 hours, have dinner
8) Hear phhhp-psssssssssssssshhhhh as cheap ASDA inner tube explodes.
9) Replace cheap ASDA inner-tube.