Everyone is welcome to join our community and become a part of Cervélo
We have our winner. Congratulations Marc from Bloomfield, MI. Thank you all for playing and learning how we engineer a Tour contender.
Inspiration: Carlos Sastre and Ryder Hesjedal already proved that a Cervélo could win a Grand Tour. So, how do we take the stiffest, lightest bike in the peloton and make it even faster?
Cervélo engineers had established the pinnacle in stiffness and weight. They had designed the fastest road bikes through aerodynamic innovation. The next step, CASE: Concurrent Aerodynamic & Structural Engineering. The CASE approach was used to maintain stiffness, decrease weight, and improve aerodynamics in a new frame set.
Balancing weight, stiffness, and aerodynamics: an increase in one parameter usually means a sacrifice in another. How do you find the perfect balance?
Making a frame stiffer usually means making a frame heavier through adding material. Reducing aerodynamic drag can mean reducing stiffness due to changing a shape. However, by determining the ideal baseline for each parameter, our engineers can tune the shape and materials to find that perfect balance. Through each improvement to the design, the parameters of stiffness, weight, and aerodynamics move closer to the desired baseline. To find out how we set our baseline, read Lab vs Reality.
Engineering the best frame requires many different attempts to find the perfect shape. Part 2 of CASE is the Iterative Design Phase
Parametric Analysis allowed our engineers to examine how each change they made to frame shape affected the outcome in terms of performance. With this knowledge, 93 different frame iterations were modeled, tested, and analyzed to find the best possible outcome. Read more on our frame shape Squoval.
Measuring stiffness: one of the tools in use by the Cervélo engineering team is Finite Element Analysis (FEA).
FEA is used to test specific load cases for a frame. Two simple examples include pedaling load case and steering load case. The pedaling load case is directly affected by bottom bracket stiffness wherein a stiffer bottom bracket area efficiently transfers your effort into propelling the bike forward. The steering load case is directly affected by head tube and torsional stiffness. Proper head tube stiffness creates precise and immediate handling for the rider. To read how we determine ideal stiffness parameters read Measuring Stiffness.
Measuring aerodynamics: Cervélo engineers use two main tools to measure the drag of a bike, Computational Fluid Dynamics (CFD) and the Wind Tunnel.
Before a frame reaches the prototype stage, our engineering team can test and compare the effect of different tube shapes in CFD. Combing CFD capabilities and a nearly 20 years of wind tunnel experience and knowledge allows the engineers to begin refining the frame before we ever begin manufacturing.
Carbon fibre is the 'material of choice' for the bikes of the Tour de France. But, what exactly is carbon and where does it come from?
Carbon fibres are fine strands of carbon material. In the chart to the left, you can see the relative size of a carbon fibre (like the ones you will find in bicycle frames today) and a human hair (represented by the red circle). However, frames are not made of just carbon fibres. Rather, frames are constructed of a mix of fibres bundled together in a TOW and epoxy or a 'Carbon Fibre Reinforced Plastic.' No one single type, or modulus, of carbon fibre is used in a Cervélo frame.
Choosing the right material: making the most of the potential of composite design.
Different areas of the frame face very different load cases. For example, a down tube is often under a bending or twisting force whereas the highest load case for a head tube is impact. Therefore, not only are different ply shapes of carbon fibre used in these locations, but different materials may also be choosen. Stiffer or higher modulus fibres are used in the down tube and stronger or lower modulus fibres are used in the head tube. How do our engineers know which to use?
The Lay-up: once you have choosen which materials go where, the next step is putting them in place
Once our engineers understand which materials are best used in each location, they can begin to develop the lay up of the bike. Hundreds of individually cut plies of carbon pre-preg are placed in a certain order. The more precisely these plies are cut, the less material is used to achieve the desired strength in reliability in a frame. The result: frames that are significantly lighter than the competition.
The tools of manufacturing: how mold manufacturing allows us to combine the composite materials and frame shape.
The main frame shapes are created by laying the precisely cut plies of carbon fibre pre-preg into a mold. Each piece must go into place in the correct orientation and in the correct order. Once the material is in place, the two sides of the mold are joined together. A bladder is inflated to compress the plies into place with approximately 120psi of pressure.
Understanding the importance of the head tube.
Cervélo head tubes are engineered and manufactured to offer the best properties for each application. For example, during a Tour stage in the mountains, a rider will hope for a frame that reacts quickly to steering input during fast descents and out-of-the-saddle climbing efforts. The R5 is constructed around a larger lower head set bearing allowing a tapering of the steerer tube in the fork to improve load paths. The result: a better climbing and descending bike.
Why our forks are more than just performance: safety first
The Tour de France demands a lot from the team bikes. Not only do the forks need to be light and stiff for performance, but they also need to be safe and reliable first and foremost. One-piece construction removes all bond joints; minimizing weight by removing all extraneous material while maintaining strength. The forks are tested far beyond the industry standard for both impact and fatigue, and even a combination of the two!
Why our forks are more than just performance: strong yet supple.
The Tour is long and hard on a rider’s body. Increased lateral stiffness in a fork can give the rider a feeling of confidence during hard out-of-the-saddle efforts and while cornering on fast descents. Too often this comes along with increased fore-aft stiffness, making those long, hard miles of the tour feel even longer and harder. By careful carbon fibre orientation and material selection, our engineers have decoupled lateral and fore-aft stiffness. The result, a stiff fork laterally with no compromise in ride quality that our riders can notice.
Making the most of a limited space: the effect of chain stays
In terms of frame design, some limitations will apply. The chain stays, for example, are limited by the crank arm and rear wheel. The outer dimension of the stays must take into account derailleurs, crank arms, and power meters. The inside chain stay dimension must take into account a variety of wheel and tire sizes and widths. Our engineers found that by making the non-drive side chain stay significantly larger, both chain stays are stiffened as a unit.
Building a better bottom bracket
In order for the bike to have a feeling of immediacy for the rider, the stiffness of the bottom bracket area is crucial. Along with the chain stays, an increase of stiffness in the bottom bracket area can have an impact climbing. The R5 bottom bracket shells are made by placing many pieces of laminate on a precision-machined steel mandrel and then rolled for compaction. Once the internal bottom bracket shell of the frame is bonded into the frame, its ultra tight tolerances ensure proper fit and longer bearing life.
Light but tough: how carbon fibre drop outs are made.
The drop outs of a frame and fork, where wheels are clamped to the frame, take some punishment on a racing bike. During the Tour, wheels can be removed and replaced on each bike several times a day by the mechanic with a great deal of clamping force. How do we offer a drop out that withstands the needs of the team without adding a huge amount of weight? Layer upon layer of carbon is laid up and compression molded to create a light-weight piece that can be compressed over and over again without loosing shape
Bringing it all together
The R5 frame is comprised of several sub-assemblies that are preformed on an assortment of mandrels by very specifically trained lay-up personnel. These sub-components are then assembled into the front triangle. Further plies and surface preparations are added to ensure complete crosslinking and compaction tying the entire assembly into a single piece front triangle during molding.
Building it up: choosing the parts for the athlete
To accommodate the personal preference of all the riders on Team Garmin-Sharp, it is important to offer as many options as possible. For the rigors of racing the Tour de France, most riders choose electronic Shimano Di2. However, the frame must work perfectly with standard cable actuated components as well. To ensure all options work, our frames are designed to use interchangeable cable stops.
Building it up: perfect shifting
The shape of the R5 saves an estimated 7.4 watts during normal riding compared to the previous R5 shape and includes clean, internal cable routing. For those who choose traditional mechanical cable components with internal routing, perfect shifting relies on a properly engineered cable path. Crucial to reducing drag in that cable path is a bottom bracket cable guide.
The race: which bike to use and when
Members of Team Garmin-Sharp can choose their own Cervélo. With the most significant time losses occurring in the mountains, the riders tend to go for frames with low weight and higher stiffness. Most of the GC riders or climbers opt for the R5. However, some riders opt for more aerodynamic advantages.
Geometry: fitting the needs of an entire team
Team Garmin-Sharp rides the same Cervélo frames that you can buy in your local Cervélo retailer. There is a large range of rider size on the team, and an even larger range when you compare to the general public. The team at the Tour fits on 4 of the 6 sizes available. Even stage 19 winner Ramūnas Navardauskas.
Our engineering team records and analyzes real world riding situations and designs a frame to perform best in those conditions. Their expertise in materials, aerodynamics, and manufacturing result in a bike that can be raced at the absolute pinnacle of the sport and with great results. The same bike that you find at your local Cervélo retailer.
Update from Ironman world champion @fvanlierde as he races his way toward Kona. http://t.co/7oiv5Dp2h6 http://t.co/7JrplxOf79 via @cervelo
RT @PorscheNL: Cervélo en Porsche, twee werelden, dezelfde DNA. http://t.co/oMyxdh9Jei Wie weet welke link fietsenmerk @cervelo met Nederla… via @cervelo
RT @fvanlierde: Read my race report about 5150 Marseille here: http://t.co/nwOCvVDhKH via @cervelo
RT @_pigeons_: Here's the full conversation I had with @PooleyEmma on her cycling retirement + videos of my favourite Pooley moments
http:/… via @cervelo
"The only problem you're likely to find on an R5 is staying within sensible speed limits…" @BikeRadar http://t.co/CWgXtR6q7Y via @cervelo
We have our winner. Congratulations Marc from Bloomfield, MI. http://t.co/ILDQNuX5Iq via @cervelo
Save your favorite bikes, comment on articles and share your stories.
Register your bike and become part of our MyCervélo community.
Authorized Cervélo Retailers are here to help you get on the road.
Have a question for us? Browse our FAQ's or ask an expert.