If you know it is 2011 or newer, there are only two choices 2011 and 2912 since the 2013 model had Tiagra derailleurs. If it is blue, it is 2012. If it is red and has Microshift shift lever and Microshift FD, it is 2011. If it is red and has Shimano STI shifter/brake lever it is 2011.

2011
Brakeset Shimano Dual Pivot brakes, Shimano STI levers
Shift Levers Shimano STI
Front Derailleur Shimano 105, clamp on
Rear Derailleur Shimano 105
Colors Gloss race red


2012
Brakeset Dual Pivot
Shift Levers Micro.shift integrated shifter
Front Derailleur MicroShift M22
Rear Derailleur Shimano 105 10sp
Colors Race Red, Royal Blue

2013
Brakeset Dual Pivot
Shift Levers Shimano Tiagra
Front Derailleur Shimano Tiagra
Rear Derailleur Shimano Tiagra
Colors Gloss White