S5 — SRAM RED AXS / Reserve 57|64

The S5 keeps the two features that defined it and rebuilds everything around them. Cervélo measures the current frame as 6.3 W faster than its predecessor and 124 g lighter, with the gain concentrated at the front: deeper fork legs, a deeper head tube, and a one-piece cockpit that inherits the V-stem layout. The rear accounts for a smaller but real share, through asymmetric seat tube and rear wheel cutout profiles that manage the airflow the rider's legs have already disturbed.

The bayonet fork is the structural idea that makes the front end possible. The steerer runs outside the head tube to the handlebar rather than through it, so the fork legs and the head tube can be shaped as one continuous surface without the bearing stack dictating their width. The trade is a proprietary interface: the cockpit is not a standard two-bolt clamp, and Cervélo builds the HB19 bar and stem in 15 size combinations so the fit is resolved through the purchase rather than through aftermarket parts.

The frame is designed around 29 mm tyres rather than the 26 mm of the previous generation, and the geometry was adjusted to keep the trail figures where they were. The wheelset is the Reserve 57|64 Turbulent Aero, developed with the frame and built on DT Swiss 180 hubs. The reference build is 7.25 kg without pedals, on SRAM RED AXS E1.