Just be careful doing this as just because you get past check-in with an overweight bag certainly does not mean you are 'safe'. They often check them, at the gate as you board which is not a good time to discover they don't like your bag. They will probably require you to check the whole thing in there and then giving very little time to remove any items you may need or not want checked. This has happenned to friends and my parents when they were only 1kg over - with qantas and Air New Zealand. Equally there has been many occasions when it has been no issue!!!