Cervélo S3 Ultegra Di2 Disc: £5,699 | 7.66kg (16.89lb)

James Bracey gets up to speed with a PB-hungry aero machine

“I have been blown away by the sheer paciness of the package”

Cervélo has given its S-series bikes an overhaul, redesigning both the S5 and the S3 models with a particular focus on frame stiffness and aerodynamics.

Unlike the new Cervélo S5, the latest S3 is available as both a rim brake and disc brake bike. The new disc-brake version uses Cervélo’s True Aero technology, which comprises a combination of specific tube shapes, sizes, and designs to improve the aerodynamic flow across the bike. At the front end, the bike has a new frame and fork shaping, and all the cables are tucked neatly inside the cockpit – made possible by a new upside-down modern take on the quill stem.

Cervélo claims these changes have saved 13 watts at 40kph over the outgoing frame.

The brand has tried to give the S3 a ride quality that’s distinct from the more aggressive S5. The S3’s stack is 16mm higher than the S5 and it has slightly skinnier seatstays and wider tire clearance, both to improve vibration dampening. In fact, the S3 has identical geometry to the Cervélo R3, a bike we rate for its ride position and performance.

Additional frame changes include a dropped down tube and rear stays that have had an aerodynamic makeover.

Cervélo has also stuck to its BBRight press-fit style bottom bracket. We have had mixed experiences with this system and have found that, like almost all press-fit bottom brackets, it develops a creak after a few months of testing. Options are available to improve this but it would have been good to see Cervélo reverting to a threaded bottom bracket.