I need a socket wrench set for taking stunt pegs off my bike. The pegs are aprox. 10cm long and have a circumference of 2.7cm. What are the metric sizes for the socket wrenches?

The drives are all in ASE measurements... 1/4", 3/8", 1/2", 3/4", 1", etc... you would probably need a 3/8" drive set, and a 'typical' socket set for those would typically include 10 - 18 mm sockets, although larger sockets can be had as part of specialty sets, although I'm having a little difficulty believing you'd need a 27mm socket on what I'm assuming is a pedal bike, although it might be more feasible if you're referring to a motorcycle, in which case, I'd recommend you go with a 1/2" drive set.