Cervelo announced the new Aero S5 shortly before the start of the Tour de France this past July. It’s a culmination of 10 years of design and testing of aero road bikes. Cervelo says it’s a faster, stiffer, and lighter frame than the S3. When you’re riding a bike the single biggest factor slowing you down is air, up to 80% in some cases. When Cervelo went to design the S5, they designed it to be the most aerodynamic bike you can ride while being in the most aerodynamic sustainable position as possible.
The S5 was built on 5 important features as explained in our recent video shoot with John Kameen. Moving from the front of the bike back, the first of those features is the dropped downtube. Rather than design a front wheel cutout where the downtube follows the rear wheel, they found after wind tunnel testing, what was faster was to drop the downtube to cover the area behind the trailing edge of the fork crown. So rather than splitting the air once over the fork crown and letting it reattach to the area on the downtube and separate again on the trailing edge of the downtube, the air is split just once rather than twice.
You’ll also notice a unique water bottle feature on the Cervelo S5. The inclusion of three water bottle bolts, instead of the typical two. Cervelo has done this to allow for more bottle positioning choices. Typically when you put a water bottle on an aero frame, you lose some of the aerodynamic properties. With the S5, you have several positions to choose from depending on which sort of bottle holder you decide to run on the frame.
Also designed into the frame is a shielded rear brake. Cervelo placed the brake mount directly behind the seat stay shoulder, essentially hiding the brake from the wind as it flows over the frame.
The Cervelo S5 also features an extended rear wheel cutout, a feature Cervelo pioneered originally on their triathlon bikes the P3 aluminum, P3, and carried over to the P4. They’ve taken that concept and adopted it to road bikes. First you’ll notice unlike their triathlon bikes, the S5 has vertical dropouts so wheel changes are just as easy as they are on any other road bike. You’ll also notice the cutout gets larger as you follow the cutout down towards the bottom bracket. This makes wheel changes easier, but also prevents road debris such as rocks from getting sucked into the frame.
BBright also makes it onto the S5. Originally introduced on their R-series bikes, the goal of BBright is to make the stiffest and lightest bikes they possibly can. To do that, they increased the width of the bottom bracket area as well as increase the diameter of the spindle area (30mm) as much as they could without interfering with chainline. You’ll notice on the S5 that the non-drive side chainstay is much beffier and oversized than the driveside chainstay. Since the non-drive side of the chainstay carries more of the load, the beefier size gives it four times the stiffness of the driveside.
Finally, the S5 is also Di2 ready. You’ll notice a battery mount available on the non-driveside chainstay as well as options on the top tube for the separate wires needed for Di2.
Cervelo offers the S5 in two frame levels. The standard S5 frame weighs in at 1,070 grams. But for weight weenies, the company says they have a VWD frame that incorporates a lot of what they’ve learned with the R5 Project California that will come in at just 990 grames. Both frames use the same molds and are said to be nearly identical when it comes to lateral and torsional stiffness.
The S5 is available through dealers now.
Standard S5 frame with Shimano Ultegra is priced $4,800
VWD S5 frame with Shimano Dura Ace Di2 will cost $9,000
VWD S5 frame with SRAM Red will cost $7,500
Photo Gallery Images after the jump