Cervélo launched the Soloist back in 2002 – the world’s first aerodynamic road bike – and 15 years on is still at the cutting edge with the Cervélo S5
Since launching the Soloist back in 2002, the world’s first aerodynamic road bike, Cervélo has consistently stayed at the forefront of the aero road bike design. The Cervelo S5, however, represents a considerably older design than the Specialized Venge ViAS and the Trek Madone. Despite this, the steed of choice for Mark Cavendish is no slouch. Overall the Cervelo S5 is claimed to save 21.3 watts over the previous VWD version of the S5 frame.
The 2017 version has been updated with a new seatpost, components and paintjob.
>>> Read more: The best aero bikes buyer’s guide
The aero cockpit of the Cervélo S5
Many of the aero features and ideas Cervélo pioneered have since been imitated by its competitors. The dropped down tube, rear-wheel seat-tube cut-out and low seatstays are now synonymous with aero bikes.
Cervélo found that a bike’s top tube has almost no effect on aerodynamics, so the top tube on the S5 is identical to that of the R5. The original S5 was slammed by the pros for its flexy front end, which made the handling as relaxed as the upright position the tall head tube forced them into. With this in mind, Cervélo has lopped 2cm off the head tube and reworked the carbon lay-up to create a front end that is apparently 35 per cent stiffer than the old S5’s.
The cut-out seat tube has been reshaped to allow the Cervélo S5 to accommodate wider 25mm tyres. However, this frame is mainly a vehicle to show off the best of Cervélo’s aero engineering, with a claimed 21.3 watt saving over the previous version.
The down tube has been lowered to sit closer to the front wheel and shielding seatstays smooth airflow around the rear brake plus, as mentioned, the new seat-tube cut-out which has been redesigned to accommodate 25mm tyres also helps.
However, since the launch of the original Cervélo S5, more modern designs have emerged. As an older design, the main difference we see is the lack of cable integration compared with the S-Works Venge or Trek Madone. The advantage of this is that the S5 is much easier to live with, especially when it comes to travelling, adjusting brakes or changing stems. For 2017, aside from a different plain job, the key difference to the S5 is a new seatpost designed to offer increased vertical compliance over the previous fully bladed post.
SRAM Red eTap and ENVE wheels help keep the weight down to 6.82kg kg – impressive for an aero bike, although it is worth pointing out the ENVE 3.4 wheels are fairly shallow at 35mm and 45mm deep.
I am a big fan of the spec here, but to do the bike justice deeper wheels would be preferable. It is also worth pointing out that the ENVE wheels are not the same as those available to purchase separately, with lower-spec hubs to keep the price down. That said, they perform well and are very stable in crosswinds. Also included is Cervélo’s proprietary aero bar, which the makers claim saves 4.4W over a round bar.
The non-integrated stem on the Cervélo S5 should enable riders to modify their position more easily than with an integrated bar/stem setup. The flattened 3:1 ratio tops are not only uncomfortable to hold but make it almost impossible to fit an out-front computer mount or a front light. The integration of a standard stem is practical for adjusting positions, though. Factor in that the Canyon Aeroad and Giant Propel both have oversized steerer tubes, meaning most stems are not compatible.
The Cervelo S5 is no armchair, but the redesigned seatpost has noticeably improved rear-end comfort over the fully bladed design of last year’s model.
The geometry is good and the S5 really comes into its own when it’s ridden fast. Once you’re up to speed it requires noticeably less effort to stay there than a non-aero bike. That said, the S5 doesn’t feel as fast as the Venge or Madone out on the road. This was backed up by our own aero testing. We performed aero testing at Derby Velodrome, with the help of WattShop. More details to follow.
On the hoods the S5 was 8W less efficient at 45kph than the Madone. When riding in an aero position on the hoods, this deficit was cut to just 2W. It is important to stress that the S5 is still significantly faster than a non-aero design.
Going uphill performance is good, especially for an aerobike. I am a big fan of the SRAM Red eTap groupset – the shifting is great and the weight lower than that of Dura-Ace.
The wheels were a tad disappointing, though. At first glance the ENVE rims look incredible, but to keep costs down the rims have been built onto lower-spec hubs. Out on the road I found the wheels flexed and I encountered both front and rear brake rub when giving it the beans. Switching to some stiffer Zipp 404s transformed the bike.
The previous version of the S5 equipped with Dura-Ace Di2 and HED Jet 6 wheels had an RRP of £7,000. At £9,000, this year’s model has had a significant price hike and struggles against the competition with regard to value. Alternatively for nine grand you could go for an S-Works Venge ViAS, which comes with a bike fit, power meter and more expensive groupset.
The Cervélo S5 is a bike that is at its best when it’s ridden aggressively, and you feel a little guilty if you ride it in any other way. Adept on both flat and rolling roads the S5 is a brilliant bike. That said, the Enve for Cervélo wheels were disappointing with regards to stiffness and the overall price is high compared to other bikes of a similar spec.