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Design Stories: Cannondale CAAD12

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Photographs: Cannondale/Philipp Nemenz

These are busy times for Cannondale.
The Connecticut brand has released a record number of new models this year, reached a new alliance with Slipstream Sports to maintain a presence in the UCI WorldTour, and will exhibit at the inaugural 1 Classic this November.
Cannondale gatecrashed the European peloton a little over 20 years ago in consort with Mario Cipollini’s Saeco squad. The  sprinter with the oversized ego and blood red bicycle, all oversized tubes and monstrous cranks, created an indelible impression.
There were other significant victories: a World Championship in 2003 for Igor Astarloa in Hamilton, a Giro the same year for Gilberto Simoni and another the following year for Damiano Cunego. The significance to Cannondale, and its latest creation, will become apparent.

The brand has remained a fixture in cycling’s top tier, joining forces this season with Jonathan Vaughters’ Cannondale-Garmin squad.
The direct link between its salaried riders  and Cannondale’s engineers is best illustrated by the latest iteration of the flagship SuperSix EVO, ridden to victory at the Tour of Utah by Joe Dombrowski, just weeks after he received the new bike along with 200 journalists at a press launch in Austria. Of equal interest, however, was the second bike, unveiled that same weekend, and on which this writer toiled up some of Austria’s unrelenting climbs: the CAAD12.
There is little anyone can teach Cannondale about building aluminium bicycles, having shocked the peloton of the early 1990s with its CAAD3 model, the first to exhibit the Power Pyramid downtube and Hollowgram chainset that have become staples of subsequent developments. Here we return to Astarloa, Simoni and Cunego: the last two Grand Tours and the last World Championship won on aluminium bikes were done so on Cannondales.

The first thing to note about the CAAD12 is its nomenclature. The previous iteration of Cannondale’s top-tier aluminium platform was the CAAD10. The absence of a ‘CAAD11’ is conspicuous and deliberate, indicative of Cannondale’s belief that the ‘12’ is a major step forwards.
Much of this confidence is owed to a proprietary computer modelling process that Cannondale calls “Tube Flow”, of a type that they believe they are alone in the industry in using. “From the ground up, we’re using flow modelling,” Jonathan Schottler, lead engineer on the CAAD12 project explains.

The process allows Schottler and his colleagues to set parameters for the manufacturing process (extrusion, tapering, the number of hydroforming steps, for example), clearances (tyre, chainring, front derailleur etc) and to focus solely on the cross sections and thickness of the tubes.
“We’re looking at torsional stiffness values in the tubes and then working on optimisation studies: studies that we can just run over and over again, iteratively and very, very quickly. This is how we’re able to achieve very well balanced tubes which the stresses flow through, and that’s kind of where the name comes from.”
The engineer’s influence on the material is limited with aluminium, he continues. Unlike with carbon, its properties cannot be changed; his only input is on the thickness and shape of the tube.
Schottler offers a tangible example of how the technology is applied: tubes no longer need be dented or crimped to gain clearance for tyres, chainrings and the like. Clearances are configured in Tube Flow before manufacturing begins, eliminating the need for such primitive methods, likely to cause stress failures.
Most important, however, is the ability of the software to optimise the distribution of material. We are handed a chainstay, cutaway to reveal a wall thickness that varies from thin to postage stamp slender. Cannondale used its Tube Flow model for the first time on the CAAD12, but will now make it the starting point for all R&D projects. The radical Slate, a bike that at a glance seems heir to all of Cannondale’s fine tradition of innovation, was the second product designed with Tube Flow.

Using a computer to analyse tube shape and distribution of material has long been the norm for carbon frames, but by applying a similar process to aluminium, Cannondale has again taken a position at the forefront of the industry when working with a material that many of its competitors considered obsolete: little more than “price point” fodder.
“You can see the way wall thickness changes, the shape changes, and it really allows us to concentrate the material exactly where we need it. With carbon, you have the ability to change the properties of the material along the length of the tube, but with aluminium, the material properties stay the same; all you can do is manipulate the shape and the thickness,” Schottler explains.

Disc drive
The next most notable aspect of the CAAD12 is that the disc version was the template, with the rim brake version derived from it.
The miniscule weight saving in favour of the disc frame – at 1094g, it is 4g lighter than the rim brake version – is perhaps less significant than the ‘disc-first’ philosophy adopted by Cannondale for a frame typically purchased by the knowledgeable club racer.

While the CAAD12 shares many features with the SuperSix EVO – an hourglass headtube, flared junctions for the three main tubes, a broader, BB30A bottom bracket shell etc – Cannondale has significantly broadened the pitch for its aluminium bike with a sophisticated disc platform, rather than a crude adaptation of mountain bike standards.
The braze-on, flat mount for the rear caliper is arguably the most interesting development of either platform. The non-driveside chainstay is mitred to create two locating lugs for the disc mount, which, when brazed into position, sets flush with the chainstay, hence ‘flat’.
“You usually have a large forging –  typically your brake mount plus drop out – to a fairly thin chainstay, so  you get a huge jump in stiffness between those cross sections and have stress risers,” Schottler explains. “Plus they’re welded on, so you get the heat effect – a weaker junction – right where they’re attached.”
All of these defects have been eliminated with the new mounting, which Cannondale – unusually for a brand that relies on the difficulty of copying as a deterrent – has patented.
Lighter, stiffer, etc.
With such developments in mind, the usual claims for increased stiffness, greater compliance and reduced weight seem commonplace at the launch of a new model, begging the question, if improvements had not been made within these parameters, then what was the point?
For the record, Cannondale claim 50 per cent more vertical deflection in the rear triangle (“smoothness”), increases in the stiffness to weight ratio at the headtube and bottom bracket of 10 per cent and 13 per cent respectively, 10 per cent more compliance from the fork’s micro suspension, and 36 per cent more “comfort” (deflection?) from it’s 25.4mm SAVE post compared to a, well, “comparable” 27.2mm pillar.
More significant is that the CAAD12 has clearance for 27mm tyres and that 25mm are spec-ed across the range. Note also that Cannondale has lowered the bottom bracket height accordingly, reducing it by 3.5mm to accommodate taller tyres.

Systematic reduction
While the lighter-stiffer-faster mantra has become de rigueur, it’s worth mentioning in the context of such a fine predecessor as the 1150g CAAD10, which gained a cult following among cycling’s cognoscenti. At 1098g, the CAAD12 rim brake frame is marginally lighter (and the disc frame lighter still, as noted above), but the full scale of the reduction becomes apparent when discussed in the context of “system weight”.

System Integration is a long-held philosophy at Cannondale, and ‘system weight’ has become something of a mantra when heralding its result. Combine the CAAD12 rim frame with the top-tier HI-MOD fork used with the new EVO (one which no longer uses a crown race) and Cannondale’s proprietary 25.4mm SAVE seatpost, and the weight saving adds up to a more significant 200g. Substitute the top-tier fork for the medium modulus spec-ed through most of the CAAD12 range, and swap out the SAVE post for a conventional carbon pillar, and the savings are still 116g.
Cannondale claim further weight savings from use of their Hollowgram SI chainset, either the flagship SiSL2 or the Hollowgram SI, both compatible with the wonderfully machined SpideRings, or their new, solid-armed junior sibling, billed as offering “Ultegra-beating performance”, and weighing 735g.
Discs in the peloton. And aluminium too?
That major manufacturers are again recognising aluminium as a viable material from which to build performance road bikes is heartening. Cannondale’s CAAD10 was considered the gold standard, but the CAAD12 is unquestionably more advanced. Even on the ferocious climbs surrounding Kitzbühel, the disc bike was willing, and on the exhilarating descents (shared with a nonchalant Davide Formolo), it was extremely stable.

With the peloton already engaged in testing disc brakes in races, might we see the CAAD12 disc at La Vuelta? Cannondale-Garmin are more likely to opt for the disc version of the Synapse they used in spring, but the return of aluminium to a WorldTour team would be a considerable coup for Schottler and his team.
Perhaps it’s unrealistic to expect Joe Dombrowski or Andrew Talansky to ride into the Asturias aboard a CAAD12, though the sight would be pleasing. For the aspirant club racer, who recognises that a high-quality aluminium chassis is almost always superior to budget carbon, and that savings registered can be reinvested in better wheels, the CAAD12 must be an appealing prospect.

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