The new Cervélo S5 is the flagship bike in the Cervelo range. In fact, so much so that it is the bike that Thor Hushovd will ride in the 2011 Tour de France. Thor will be hoping that Cervelo’s claim, that the S5 will save riders nearly 37 seconds over a 40km course (at 40km/h), compared to the Cervelo S3.
The 92g of drag reduction comes with some new tube shaping, which has it’s roots in the original development of the Cervelo Triathlon Bikes such as the Cervelo P4. The rear end of the S5 includes a seat tube with a deep-section profile, close-fitting rear wheel cutout, and nearly upright aero-section telescoping carbon seatpost. The S5 will use a conventional rear brake instead of the P4’s integrated calipers. According to Cervélo, the aero seatstays are set a little more broadly up top to help direct air around the caliper.
Cervélo have opted to stick with a straight 1-1/8in head tube for a narrower hourglass-shaped frontal profile which should help keep the front end rigid. Cervélo includes it’s asymmetric, extra wide and oversized bottom bracket, which is similar to that found on the R3 and R5. The derailleur housing on the S5 is fed into the top of the top tube as on the S3.
Weight on the S5 is also an improvement over the S3, 990g for a painted frame, 340g for an uncut fork, and a 12 percent jump in drivetrain and torsional stiffness.
While the look and aerodynamic features of the new S5 are inspired by the P4, the geometry is taken from the Cervélo R3. So, you can expect taller head tubes than in previous years and proportional head tube angles for more consistent handling across the size range. Buyers looking for an aero machine that can serve double duty as a light time trial or triathlon rig will also take interest in the two-position seatpost head.