May 28, 2015 – Belgian rider Philippe Gilbert of the... Read more →
How’s this for a business model? We’re going to build a product twice as light as it needs to be and we are going to lose money on each and everyone we make. That, in a nutshell, is the Cervelo RCA. The $10,000 follow-up to the R5CA, the California made boutique frame that smashed previous stiffness-to-weight ratio records, weighing less than 700 grams, yet was stiff enough for Ryder Hesjedal to pilot to Giro victory.
The RCA, of which only 325 have been made, came out of its California research facility. Cervelo was able to lose money on each frame because it was really a test case, using materials and techniques that ended up in its Asian made production bikes. It’s just a test bike that happened to be raced on the WorldTour and could be ridden by anyone with $10,000 lying around, that’s for the frame and fork alone, of course.
The design brief handed to Cervelo engineers was daunting. Make it lighter and stiffer than the lightest, stiffest bike ever made, but don’t forget about ride quality and durability. And, oh, by the way, make it aero too. Incredibly, Cervelo engineers checked off every box on the brief. The bike weighs 667 grams for a painted 54cm, with all the hardware, and stiffness has been strategically rearranged for ride quality, a little more up front for handling and little less at the BB for a lively and responsive feel. Aerodynamically, the bike sucks up 10 watts less energy than a typical road bike and seven less than the R5Ca.
To get there Cervelo ran 10 FEA (finite element analysis) simulations a day and overnight CFD (computational fluid dynamics) to quantify aero gains. It’s a process Cervelo dubs CASE, Concurrent Aero and Structural Engineering. The result was 93 complete virtual frames had been designed before carbon was ever put to mold. The solutions that this process produced are both familiar and striking. During S5 testing Cervelo found their Squoval tube shapes were actually quite aero thanks to the rounded corners. To amplify this they created Squoval3, which adds a nose to the tube and results in a shape similar to the truncated airfoils used by Trek and Scott. To ensure stiffness and ride quality Cervelo was careful about where they put that nose, using it only in areas where it could truly help — the head tube, seat tube, low on the down tube.
While smart use of both high and intermediate modulus of carbon delivers much of the stiffness and ride quality at the low weight, two revolutionary techniques take it to the next level — torsion boxes and bulkheads. Bulkheads are internal walls used at the head tube and bottom bracket, which cost only 2 grams in weight but add 6 percent of the stiffness. The torsion box is an internal structure at the bottom bracket-chain stay junction that lets this critical area rely on two sets of tube walls. The challenges this presents in lay-up and molding are daunting, which is why it was pioneered at the California facility.
Some of the materials in the bike go well beyond the typical hi-mod carbon claims. In fact, Phil White, managing director and cofounder of Cervelo, clearly dislikes the industries reliance on that term in marketing. Carbon that is both super-stiff and super-strong does not exist. Because of this, frames that claim 6-ton carbon must also use a generous amount of lower modulus carbon for durability. In the RCA, Cervelo uses six different carbons, as well as two other cutting-edge materials. The steer tube is incredibly important and often overlooked, which is why it is typically the most recalled component in the industry. Cervelo found a partner that can grow nickel plating onto a thin carbon steer tube, resulting in massively improved strength and resistance to crushing forces with no weight penalty. Remember that if you buy an RCA, because your riding buddies will ask why your $10,000 frame has an aluminum steer tube.
Cervelo is also entering the nano-resin game. They had resisted using nano particles previously because they found, while the resins can decrease micro cracking between carbon layers, the technology degrades compressive strength. 3M approached Cervelo with a new material, Powerlux, using nano-silica that actually increases compressive strength. At seven times more expensive than standard resins it is used only in strategic areas.
Of course, other nice touches and incredible tech abound. The dropouts are hollow to save five grams and the chain stay is dropped slightly to provide perfect cable path. The bottom bracket has a magnet embedded in the carbon right where your Quarq or SRM needs it and that magnet is included in the frame weight. Of all the numbers that amazed us, the most striking is the fact that to ride this frame Garmin riders needed to add more than the weight of the frame in ballast. Imagine that, to be UCI legal the weight they added was well beyond the 667 grams of the frame. Since small sizes are in the 500-gram range some riders are almost doubling the weight of the frame in ballast.
What can we say about the RCA on the road? Take the lightest, stiffest bike you have ever ridden and multiply those benefits by a factor of 10. The bike makes us feel that gains based on weight and stiffness must be calculated exponentially. Sure, it’s only a handful of grams lighter than the R5Ca, the stiffness has been slightly reorganized and the rear is a spot more complaint, but they seem to add up too much, much more. There is a fury to the way the bike reacts to power, it leaps from under you, but the feeling continues beyond the initial acceleration. Each pedal stroke delivers a new surge forward. To truly appreciate this performance you need to be a lightweight climber that thrives on steep pitches and changes of tempo, but in those hands the RCA is a formidable weapon.
Thanks to the well-rounded design brief other riders get to feel plenty of the bikes performance. Bigger riders that excel on the shallower pitches of big ring climbs will find the lightweight lets their diesel engine spin a little faster and even the aero helps out when the speed gets in to the high teens. In fact, riding this bike for three months, in all conditions, over every type of terrain, we failed to find a type of racer or kind of road where this bike isn’t ideal. For the criterium rider it handles the biggest of sprints and thanks to the stiffer front end, the fastest, most perilous of lines through a corner. For the breakaway specialist the aero is a welcome companion and its combination of light weight, ride quality and power transfer mean the aero comes in a package ideal for an epic solo day when the road is not pancake flat.
The bike’s geometry is certainly race focused, and a bit surprisingly for a bike where no stone of performance appears to be unturned, each bike, from the 48 to the 61 cm has the same chain stays, 405mm. Combine this with the ultra lightweight, steep head tube, short front center and stiff platform and the bike feels busy on the road. For large riders without a fluid pedal stroke or tidy upper body the ride can surge and wobble a bit. It’s certainly not the in the saddle stability longer stays and a heavier platform gives you.
If you want to ride the stiffest, lightest bike on earth find a Cervleo RCA. Don’t have $10,000 or a contract with Garmin? The technology has already trickled down to the new R5, which is after all the entire point.
The kind of rider you are is almost irrelevant. The RCA delivers performance in every single category, unless you are just looking for a stable platform to tick over long Grand Fondo miles. Climber? Check. Sprinter? Check. Breakaway artist or rouleur? Check. Grand Tour winner? Check. Classics winner? Check. This bike does all things better than other bikes do one.
The Bottom Line
Price: $10,000 (frameset)
Size Tested: 58cm
Weight: Dura Ace 9070 Di2 build. 14.5 lbs with pedals and cages.
As Tested: Two separate builds were tested, DA 9070 Di2 with C35 wheels and SRAM Red with Zipp 303 clinchers. The Zipp build tipped the scale at less than 14pounds.
May 28, 2015 – Belgian rider Philippe Gilbert of the... Read more →