Cervelo R3

Stuart O’Grady on his way to winning the 2007 Paris-Roubaix

Fabian Cancellara on his way to win the 2006 Paris-Roubaix on his R3

Carlos Sastre in the Alpes during the Tour

“Best bike we’ve ever ridden”
- 220 Magazine

That's right, Cervélo and Team CSC designed a bike originally focused on the demands of one specific race. After Cervélo had finished project FM-28, the Soloist Carbon, there was one race left for which Team CSC really wanted something special - Paris-Roubaix. For the world's most grueling test of road bikes, Team CSC wanted a frame that was bulletproof, yet comfortable and light. So we started project FM-41.

By March 2006, Team CSC received the fruits of this project, the R3. By April, Fabian Cancellara had won Paris-Roubaix on it. Then 12 months later, Stuart O’Grady was the first across the finish in Roubaix on his R3. Two starts, two wins, not a bad testament to our ability to tailor a design to a specific race.
 
Of course, it didn't take long for people to recognize that if this frame had all these attributes, it would be a shame to restrict it to one race. The combination of lightest and stiffest would mean that, finally, there is a climbing frame that is not only fun to ride uphill, but also laser-precise downhill. And, the comfort from the incomprehensibly thin (yet engineered-to-be-strong) seatstays would mean it would be ideal for long rides, from centuries and gran fondos to the toughest mountain stages of the grand tours.
 
How did Cervélo achieve this? By tossing out preconceived notions about bicycle design and starting from scratch. With a new, in-house developed construction method, purpose-driven tube shapes and new lay-up designs, the R3 achieved what would seem impossible: extremely light weight + outstanding stiffness, yet comfortable and strong to withstand the age-old cobbles at 50 kph. This claim does not come from some biased internal test. These tests were performed and published in independent magazine tests. What’s more, some of the tests were even performed and published by our competitors!

Which brings up the question: when is and when isn't the R3 your best choice? If you are looking for the absolute fastest bike on a variety of terrains, the Soloist family of frames is your best bet. But, if the absolute lightest bike is your goal (without sacrificing stiffness or strength), you can't do any better than the R3 range. As a benefit, the R3 will also fit wide tires, even narrow cyclocross tires, for those interested in riding through mud or harsh winters. So, in short, the R3 is your best choice if you are looking for the world leader in the following:

Strong and ideal for bad conditions:
- Victory in the world's toughest race, Paris-Roubaix
- Lightest frame ridden by the heaviest rider in that race
- Tire clearance for 27mm special Vittoria tires

Light yet stiff in bottom bracket and torsion:
- Lightest and stiffest frame in the ProTour
- Winner of the TOUR Magazin (Germany) test of ProTour bikes
- The only claimed 900g frame that was actually 900g (VeloNews)
- TopVelo (France) frame of choice for superlight bike project
- Winner of stiffness-to-weight tests (by a mile we may add) performed and published by some of our colleague bike companies

Squoval downtube & chainstays - Optimized for the highest possible stiffness-to-weight ratio (STW), the downtube and chainstays have a Squoval shape.

Multi-shape toptube - The toptube loading case is a lot more complex, hence it is Squoval near the headtube and seattube and oval in the center section.

Oversized bottom bracket area – The increased volume of the bottom bracket area provides great STW. The smooth contours of the BB volume help both for this BB stiffness and also for its strength as the fibers have a much more continuous path to transfer the loads better.

Lay-up optimization - The stiffening plies are added to the sides of the tubes where they have the greatest effect in bending. They are feathered to distribute the loads into the structure. We also add more plies on the bottom of the down tube, the headtube and the toptube to distribute the loads from a potential headtube impact. Finally, we add Kevlar to that same area and downtube to prevent catastrophic failure.

Seatstays - We don't have a catchy marketing name for these seatstays (send in your suggestions), but they are quite simply the most amazing seatstays on any bike – a true testament to the skills of our engineering team. We have always known that the seatstays end up carrying very small loads, an effect that is even more dramatic in combination with the new Squoval chainstays. The seatstays in an R3 are almost unnecessary for the vertical loads, they only provide torsional stiffness. Therefore, we were able to design the R3 seatstays to act as leaf springs in the vertical plane while having a more standard dimension in the lateral plane for torsional rigidity. Thus it combines strength, comfort, torsional stiffness and minimal weight.

Squoval downtube

R3 frames ready for assembly at our Toronto facility

The downtube and chainstays of a bicycle frame mostly see lateral bending, even if the frame as a whole is in torsion. Yet virtually all frames on the market sport round or oval downtubes and chainstays. Excellent shapes to counter torsion of those tubes, but not lateral bending. A box section is the best shape to counter lateral bending, which is why we use a box-inspired shape on the Soloist Carbon chainstays (of course the downtube on the Soloist Carbon is TrueAero-shaped for aerodynamic reasons). On the R3, we squared off the box shape even more, leaving only a small ovalization of the shape to boost its buckling strength. This squared-off oval, or Squoval, significantly increases the stiffness-to-weight ratio (STW) of the shape in lateral bending and is used in the chainstays and the downtube. The front and rear of the toptube also use the Squoval shape, but it transitions to oval in the center to counteract the torsional loading in that section.

Smartwall® for Carbon

Upon hearing Smartwall, most people immediately think of Cervélo’s method to obtain excellent lateral stiffness in an TrueAero tube. But the Smartwall principle is universally applicable, not just on aero tubing. After the tube shapes are optimized, the lay-up allows us to further refine the character of the bike. In fact, Squoval tubes are very well suited for the Smartwall application as they have two sides that are very far removed from the central plane – i.e. adding even a small amount of extra material there increases the lateral stiffness significantly. To properly distribute the loads from the Smartwall section into the rest of the tubes, the additional plies are feathered.