R5 — Dura-Ace Di2 / Reserve 34|37

Cervélo quotes the current R5 frame at 651 g, 130 g lighter than the frame it replaces, a reduction of 16 per cent achieved by rewriting the layup rather than by changing the fibre. The fork adds 298 g. The complete bicycle is quoted at 5.97 kg in size 56 in the RED and Dura-Ace builds, which is 830 g below the UCI minimum for mass-start road racing.

That figure is a design statement with a practical consequence. A bicycle below 6.8 kg cannot be raced in a UCI mass-start event without ballast, and Cervélo has built a frame whose natural build weight sits under the limit. The rider who buys it for the mountains is buying acceleration and climbing rate; the rider who buys it to race is buying a frame that will be weighted to the minimum and will carry that mass low, in the bottle cage area or the bottom bracket, where it costs least.

The fit geometry is now identical to the S5, so a rider who trains on one and races the other does not rebuild their position between them. Chainstays are 410 mm across the entire size run, and the bottom bracket drop was adjusted for 29 mm tyres. The reference build is 5.97 kg without pedals, on Dura-Ace Di2 R9200 and the Reserve 34|37 TA SL wheelset.