~12kg for anyone wondering. Minimum bicycle weight in the Tour de France is 6.8kg (~15lb). It's possible to make bicycles significantly lighter than this, but most manufacturers don't because of the rules of the Tour. I do recommend to anyone who hasn't done it yet to take a moment and marvel at the technological accomplishment that is the bicycle. The car takes far too much credit but ultimately it can only work by…
1) Fairness: While differences between bike manufacturers are large, the competition is about primarily athletics & setting standards allows less well resourced rider teams to compete. 2) Safety: Lighter bikes may compromise on strength/safety. Tours are already dangerous enough as is, a bike breaking poses a danger to all riders on the course not just the rider. Weight minimums ensure that there's not an attempt to drop the structural weight below safe limits.
That said, weights can be decreased over time if there are legitimately new weight saving technologies that do not compromise strength of the bike.