I am either going to buy a 2012 Specialized Sirrus Elite, or the 2011 Specialized Sirrus Expert.

However I have no idea whether to get the 23 or 30 cm Abus Granit-54 X-Plus.

I will be commuting with the Bike to work, and then leaving it in my flats key-coded storage room, attached to a standard U Shaped Rack.