Cannondale frameset weight:
999g frame, 436g fork, 162g seatpost for a painted 56cm
7.8kg total
180g saved if you go Hi-mod.
SL7 pro frameset weight
920g frame, 350g? fork
Complete weight of 7.3kg.
165g saved on the frame, some on the tyres, and inner tubes, as it appears S-Works Turbo tyres and the lightweight inner tubes would save you about 100g.
Rapide CLs are probably a touch lighter? The cannondale ones are crazy wide. 32mm.
Gone are the days when Supersixes used to be the lightest frames on the market!