VeloClub is CyclingTips’ membership program which brings us closer to our members, and connects likeminded cycling enthusiasts.
by Matt Wikstrom
January 30, 2017
Photography by Matt Wikstrom
TECH NEWS BROUGHT TO YOU BY BIKEEXCHANGE
The number of road disc bikes in Cannondale’s catalogue has been steadily growing over the last few years with the most recent addition being the SuperSix EVO Disc announced last year. This means performance-oriented riders now have a choice between two distinct disc-equipped race bikes — the SuperSix EVO and the CAAD12 — made from two very different materials, carbon fibre and aluminium alloy.
In this review, Australian tech editor Matt Wikstrom compares the performance of each bike and assesses the influence of the two materials.
In a market where carbon fibre has become the material of choice for road bikes, Cannondale has steadfastly continued to refine and improve its aluminium frames side-by-side with its carbon fibre offerings. As a consequence, the company’s Elite range of road bikes comprises 11 carbon fibre and six alloy models.
Cannondale created its first aluminium frame in 1983, a touring-specific bike that was made in the USA, and it wasn’t long before the company became widely known for its alloy frames. Early enthusiasm for the brand was driven by MTB followed by an enormously successful partnership with Saeco and Mario Cipollini during the late-90s as Cannondale became the first American frame manufacturer to equip a professional European road cycling team.
As Cannondale’s relationship with professional racing continued into the new millennium, the company started to embrace carbon fibre. It was a gradual process, starting with the top and down tubes of the Six13 for 2005, followed by the front triangle of the SystemSix for 2007. These carbon/alloy hybrid frames were eventually replaced by the all-carbon SuperSix in 2008 before a major design overhaul ushered in the ultralight SuperSix EVO for 2012.
Cannondale kept on refining its aluminium road chassis throughout this period. The CAAD3 that appeared in 1997 was replaced by the CAAD4 in 2000 and then there was a fresh iteration every 2-3 years until the CAAD10 was unveiled for 2011. After that, there was a hiatus of five years (and the CAAD11 was leapfrogged) as the CAAD12 was developed for 2016.
While the SuperSix EVO was also updated for 2016, the CAAD12 went a step further by including a disc brake version. It wasn’t Cannondale’s first road disc bike — a disc-equipped version of the Synapse had been created for 2014 while one CAAD10 Disc model was added to the catalogue for 2015 — but it was a sure sign of the company’s expanding commitment to disc brakes.
Cannondale has not been alone in this strategy, since the trickle-up of disc brakes from endurance-oriented road bikes to race bikes has become an industry-wide phenomenon over the last year or two. Two disc-equipped SuperSix EVO models were subsequently announced for 2017 despite the UCI putting a stop to its disc brake trial after just a handful of races in 2016.
Now that the 2017 racing season is underway and the UCI has re-started its disc brake trial, there is fresh optimism that road disc bikes will become race-legal. The Cannondale Drapac team contested the Tour Down Under with SuperSix EVO Disc bikes but there is no indication when (or if) disc-equipped bikes will ever be race-legal.
Cannondale offers buyers a choice of two road disc race bikes that make use of very different materials. The CAAD12 Disc (left) has an aluminium alloy frame while the SuperSix EVO Hi-MOD Disc (right) has a carbon fibre frame.
Be that as it may, disc brake versions of the CAAD12 and SuperSix EVO are on the market now and I was recently given the opportunity to ride both bikes thanks to the brand’s Australian distributor, Monza Imports.
Cannondale is proud of the CAAD12, boldly proclaiming that it is “the finest alloy racing bike ever made.” Given the company’s devotion to the material and the history of its accomplishments, I’m not inclined to argue with them. But as a niche market that has largely been ignored by the majority of major manufacturers, there’s room for the cynics to argue that there isn’t much competition for that title.
Nevertheless, there is no indication that Cannondale has been resting on its laurels or is about to give up on the potential of aluminium alloy. The new chassis continues with 6069 aluminium alloy that was first adopted for the CAAD10. It’s a relatively new formulation that is significantly stronger (up to 40%) than 6061. As a result, Cannondale’s engineers were able to save 200g by adopting 6069 for the CAAD10.
This time around, the weight savings are ~50g for the frame and up to 200g for the so-called system (frame, fork, headset, seatpost) compared to the CAAD10. What is more interesting is that the weights for rim- and disc-brake versions of the CAAD12 are essentially identical: 1,098g for the rim-brake frame versus 1,094g for the disc version (56cm frame size).
Cannondale’s CAAD12 Disc makes the most of its simple, classic lines.
Cannondale claims the CAAD12 offers an impressive 36% increase in compliance at the saddle when compared to the CAAD10. A switch from a 27.2mm seatpost diameter to 25.4mm provides most of the comfort along with some thinning of the top tube and the seatstays. The rear triangle is suppler too (50% more compliance than the CAAD10), increasing the amount of micro-suspension provided by Cannondale’s SAVE technology.
Cannondale’s engineers also managed to increase the stiffness of the CAAD12 in key areas. Subtle changes to the shape of the headtube increased front-end stiffness by 10% while a switch from a BB30 bottom bracket shell to BB30A (that is 5mm wider) improved stiffness in this region by 13%.
The CAAD12 may have been five years in the making, but Cannondale’s data clearly show that the company has been able to make significant improvements to the chassis. The disc-brake version appears to have benefitted most from this overhaul, however it is curious that the fork remains largely unchanged since the introduction of the CAAD10 Disc compared to that new ideas applied to the SuperSix EVO Disc.
The SuperSix EVO owes much of its DNA to the work done by Peter Denk leading up to the launch of the bike for 2012. With a background rich in composites experience, Denk set about overhauling the SuperSix, Cannondale’s first all-carbon race chassis. The result was an ultralight frameset boasting significant improvements in almost all regards.
The SuperSix EVO Disc shares the same simple, classic lines as the CAAD12 Disc.
The company revisited the SuperSix EVO for 2016 — this time without the help of Denk, who had moved on to establish his own composites consultancy — and managed a variety of refinements. These included a 21% increase in the compliance of the fork, 36% increase in saddle deflection (the bike inherited that same 25.4mm seatpost diameter as the CAAD12), and an extra 15% vertical deflection was added to the rear triangle.
At the same time, the torsional stiffness of the frame was increased by 12% at the head tube and 11% at the bottom bracket (due largely to a switch from a BB30 bottom bracket to BB30A).
All of these refinements were achieved without any weight penalties. Indeed, Cannondale’s engineers managed to trim 65g from the combined weight for the combined frame, fork, headset, and seatpost. At the time of release, however, there was no disc brake version of the SuperSix EVO like there was for the CAAD12, but the company was working on it.
Coming up with the disc brake version of the SuperSix EVO was a fairly major undertaking. The frame and forks had to be re-engineered to contend with the braking forces associated with disc brakes and new moulds were required to accommodate the change in rear hub spacing (from 130mm to 135mm) and new cable routes.
All of these extra considerations had to be introduced to an ultralight frameset that had already been highly refined for rim brakes, so it wasn’t really surprising to see it gain weight when it was unveiled last year. According to Cannondale’s numbers, a 56cm frameset gained about 130g, lifting what was a 777g frame to 829g, and the fork 80g for a final weight of 360g.
It is worth noting that these numbers apply to the SuperSix EVO Hi-MOD Disc frameset, where the Hi-MOD moniker indicates the use of pricier high-modulus carbon composites for maximum weight savings. There is a second version of the frameset dubbed SuperSix EVO Carbon Disc that is significantly cheaper, but it is a little heavier without compromising the ride characteristics of the Hi-MOD version.
The specifications for both versions of the SuperSix EVO Disc frame are identical, and mirror those for the CAAD12 Disc too: Di2-ready, tapered head tube (1.125inch upper bearing; 1.25inch lower bearing), 25.4mm seatpost, BB30A bottom bracket shell, flat-mount brake mount to suit a 140mm rotor, internal routing for the rear brake hose, and rear dropouts to suit a standard 9x135mm quick-release axle.
The only notable difference between the SuperSix EVO Disc and the CAAD12 Disc relates to cable routing for mechanical groupsets. The SuperSix EVO Disc opts for external routing while the CAAD12 Disc provides internal routing.
The external gear cable routing on the SuperSix EVO is very tidy and easy to service.
As mentioned above, there are far more differences between the forks of the two bikes. The SuperSix EVO Disc fork makes use of a 12x100mm thru-axle compared to a standard 9mm quick-release axle for the front end of the CAAD12 Disc. The brake mounts also differ (CAAD12, post; SuperSix EVO, flat), as does rotor size (CAAD12, 140mm; SuperSix EVO, 160mm) and brake house routing (CAAD12, external; SuperSix EVO, internal).
Clearly, the fork of the SuperSix EVO Disc does a much better job of keeping pace with current trends, and as a result, the CAAD12 Disc fork looks a little outdated. However, that bike doesn’t suffer from a mismatch of axles like the SuperSix EVO Disc, which is likely to create some compatibility issues when owners go about borrowing or upgrading the wheels.
This is not an issue that’s unique to Cannondale though. All road disc bikes are currently plagued by compatibility issues related to the variety of hub axles, calliper mounts and rotor sizes that are in use. At present, there is no indication that this will ever end so consumers can only wonder how future-proof their new road disc bike will be.
There are two CAAD12 Disc and four SuperSix EVO Disc models in Cannondale’s 2017 road catalogue, as set out in the table below:
Cannondale have positioned the SuperSix EVO Hi-MOD Disc as a high-end product with builds to suit. By contrast, the CAAD12 Disc and, to a lesser extent, the SuperSix EVO Carbon are far more affordable.
Nevertheless, there is an Ultegra build with the same set of wheels that helps to put the price of each frameset into perspective. At AUD$3,799/US$2,600, the CAAD12 is the cheapest option, but there isn’t the same kind of premium attached to the SuperSix EVO Carbon (AUD$3,999/US$3,000) as there is for the SuperSix EVO Hi-MOD (AU$5,699/US$4,200).
The 54cm CAAD12 Disc Ultegra supplied for this review weighed in at 8.33kg without pedals compared to 8.00kg for the SuperSix EVO Hi-MOD Disc Ultegra sans pedals (also 54cm). Thus, on the basis of weight alone, buyers will be paying a 38-50% premium for a 4% saving on the heft of the bike.
The CAAD12 Disc Ultegra and SuperSix EVO Hi-MOD Disc UItegra share many of the same parts however the latter is considerably more expensive.
That isn’t to say that the SuperSix EVO Hi-MOD Disc is a portly bike. The 56cm Ultegra Di2 build that Matt de Neef reported on at the launch featured a 35mm carbon clincher wheelset and weighed 7.4kg, so it is possible to get the bike down to a racing weight, albeit with the extra expense of a carbon wheelset.
Once again, this is not an issue solely limited to Cannondale’s road disc bikes. Now that the number of disc-equipped race bikes on the market is growing, it’s clear that there is significant weight penalty attached to the new braking system. In any other setting, such concerns would be relatively easy to dismiss, but for those racers trying to maximise the competitive edge of their equipment at a reasonable price, rim brakes cannot be trumped.
Buyers looking at the CAAD12 Disc and SuperSixEVO Disc will find that there are nine frame sizes on offer. Those riders that are either very short or tall will be pleased to see 44cm and 63cm frames. Importantly, the geometry for the two bikes is identical, plus it matches the rim-brake versions, as set out in the table below:
With that said, there is one minor difference between the two bikes: the CAAD12 Disc has a horizontal top tube for all frame sizes; by contrast, the top tube of the SuperSix EVO Disc has a very subtle slope, and hence the seat tube is a little shorter for some frame sizes (up to 11mm) as shown in Cannondale’s detailed geometry charts for the CAAD12 Disc and SuperSix EVO Hi-MOD Disc.
Otherwise, the two bikes share the same short rear end (chainstay length 405-9mm, increasing with frame size) and relatively short head tube for a reasonably aggressive fit. That fit is moderated a little by the 25mm tall headset bearing cap that is supplied with each bike, though in the case of the SuperSix EVO Disc, there is a second essentially flat cap included (installed underneath), so buyers have of choice of using one or the other.
As mentioned above, the two bikes supplied for this review shared many of the same components including Shimano’s 11-speed Ultegra mechanical groupset, Mavic’s Aksium wheelset with 700x25c Yksion tyres. Gearing 52/36T crankset; 11-28T cassette) was identical for the two bikes too, however the CAAD12 was supplied with carbon FSA SLK cranks while Cannondale’s alloy HollowGram Si cranks were installed on the SuperSix EVO. The SuperSix EVO also had higher quality versions of the stem, bars, saddle, seatpost, and bar tape found on the CAAD12.
The crankset is one obvious difference between the two bikes. The CAAD12 opts for a carbon fibre crankset from FSA.
Almost all of the weight difference between the two bikes (330g) can be attributed to the framesets. Cannondale’s numbers show that the SuperSix EVO Hi-MOD Disc frame is 267g lighter than the CAAD12 Disc frame, leaving just a handful of grams to be shared amongst the fork and components. Interestingly, the FSA SLK crankset was actually lighter (598g, with both chainrings) than the HollowGram Si crankset (618g).
There is just one choice of colour for the CAAD12 Disc Ultegra (called Vulcan Green) while there are two colours for the SuperSix EVO Hi-MOD Disc Ultegra (white/black or green/black). I couldn’t find fault with the finish of either bike sent for review, though the matte white paint used for the SuperSix EVO was quick to pick up all sorts of grubby marks that were difficult to remove.
The prospect of comparing the performance of Cannondale’s finest aluminium and carbon race frames side-by-side was an exciting one. After all, these materials are generally viewed as occupying opposite ends of the ride quality spectrum, even though there is no hard data to support this notion. Nevertheless, popular opinion and anecdotal evidence continue to favour carbon fibre for its exceptional damping capabilities while criticising aluminium for its unnecessary harshness.
Like the SuperSix EVO Disc, the CAAD12 Disc has a carbon fibre fork, however the front brake hose is externally routed and makes use of a standard quick-release axle.
Over the course of several weeks, I went from one bike to the other, always making sure that the tyre pressures were consistent, and to keep the variables to a minimum, I swapped one saddle and post combination between the two bikes. Each bike was subjected to a variety of routes and road surfaces, and as the comparison progressed, I started to assess the influence of different tyre widths and wheelsets.
Overall, both bikes proved to be pragmatic race bikes with a great combination of sure and steady handling with sharp and precise steering. Going from one bike to the other, I never noticed a difference in either aspect, so the difference in fork materials and front axles had no obvious effect on the steering and handling. In short, both bikes were well suited to fast and aggressive riding.
Both bikes also lived up to expectations for a race bike in terms of chassis stiffness. There was no obvious flop or sway when I was sprinting out of the saddle and attacking steep pinches, however the CAAD12 always seemed to have an edge over the SuperSix EVO. I can’t say if the CAAD12 is actually any stiffer than the SuperSix EVO; I simply preferred the way that it responded to my sprinting efforts.
I mentioned above that Cannondale went to the trouble of increasing the stiffness of the head tube and bottom bracket of each bike by 10-13%. I haven’t ridden the previous iteration of either bike, so I can’t say if this is something that can be felt by a rider, but lab tests have shown that the majority of riders have trouble detecting a 10% change in tyre pressure. I’m not dismissing Cannondale’s claims, but for those owners of a CAAD10 or the previous SuperSix EVO, I expect the difference is a minor nuance.
The SuperSix EVO Disc has a fork that makes use of a 160mm rotor and a 12mm thru-axle.
Based on the weights presented above — 8.00kg for the SuperSix EVO and 8.33kg for the CAAD12 — it was clear the bikes weren’t lightweights, so I wasn’t really surprised when they were slow to accelerate. This was most noticeable from a standing start and on steep slopes, but it also handicapped the overall performance of each bike. I wouldn’t go so far as to call either bike cumbersome, but I was convinced they had more to offer.
Any rider that has had any experience with Mavic’s Aksium wheelset will understand that it is a low-cost entry-level product. The disc-ready version weighs over 2kg, and as such, really has no place on a race-oriented bike. For a reasonably priced bike like the CAAD12 Disc, it’s a forgivable economy; for the SuperSix EVO Hi-MOD Disc, much less so.
I was able to drop over 600g from the weight of each bike by ditching the Aksiums in favour of Prime’s RP-38 road disc carbon clinchers, a reasonably low-cost wheelset (AUD$1,281/US$1,004) that had arrived for review. The effect was immediate, improving the responsiveness and agility of both bikes to a level that would satisfy most racers.
Once again, I had to give the CAAD12 Disc an edge over the SuperSix EVO Hi-MOD Disc. My impression was that it was consistently sturdier under load, and therefore more satisfying when sprinting out of a corner or punching over short, sharp pinches. The SuperSix EVO was still very good in this regard, so the difference was really a matter of nuance.
The front brake of the CAAD12 makes use of a 140mm rotor.
Which brings me to ride quality. I spent far more time assessing this aspect of the bikes than any other. It’s an elusive trait, and most of the time, there’s very little to judge. It is only when the bike is challenged with obvious insults, like potholes, ruts, and cobbled surfaces that the response of the bike can be assessed. The feedback passes in an instant, leaving nothing in its wake, so I had to spend a fair bit of time on each bike to build up a good sense of its ride quality.
In absolute terms, the CAAD12 Disc provided a reasonably firm ride, transmitting a noticeable (but not overwhelming) amount of road shock and buzz. On smooth bitumen, this was hardly perceptible, and I couldn’t separate one bike from the other. But as the terrain became rougher, the CAAD12 Disc consistently transmitted more vibration, where any kind of sharp hit (e.g. from a pothole) was keenly felt.
By comparison, the ride quality of the SuperSix EVO Hi-MOD Disc was muted, though not to the extent that it eliminated all vibration and shock. I still had some sense of the terrain that I was travelling over, which I find pleasing and perhaps even indispensible for judging road conditions.
While there was a perceptible difference in the ride quality of the two bikes, it never amounted to anything over the course of a long ride (~4 hours). On these rides, I went out of my way to sample rougher roads, and while the SuperSix EVO was always “softer” and “quieter”, I never felt any fresher at the end of the ride.
Both road disc bikes often generous tyre clearance.
All of these impressions were based on riding each bike with the stock 700x25c Yksion tyres at 60psi, front and rear. I expected that wider tyres would smooth out the ride of both bikes, and indeed, after swapping to 28c Vittoria Rubino Pro tyres (inflated to 50psi), that’s exactly what I found. Nevertheless, road shock and buzz was still more noticeable when riding the CAAD12 Disc, albeit on a smaller scale.
Importantly, I noticed there was essentially no difference between the ride quality of the CAAD12 Disc fitted with 28c tyres and the SuperSix EVO Hi-MOD Disc with 25c tyres. Had I been blindfolded, I would have had trouble separating one from the other, although when it came to big, sharp hits, the CAAD12 seemed to relay a little more shock. Thus, the difference in ride quality for the two bikes was of the order of one tyre size and around 10psi.
There was ample clearance for the 28c tyres on both bikes, however this is the largest tyre size that Cannondale can recommend without contravening strict ISO standards (that dictate a minimum of 4mm clearance). Be that as it may, I found that I could fit 30c tyres (Schwalbe S-One) without any concerns about tyre rub, albeit with less than 4mm clearance in some places. These tyres proved to be a better choice for longer outings on unpaved roads but they weren’t enough to transform either bike into a gifted gravel grinder (though I was still able to traverse some pretty challenging terrain).
The Aksium wheelset may have been heavy, but I didn’t have any trouble with it during the review period; likewise, the rest of the components on each bike. I initially had some problems with plugs for the brake hoses on the SuperSix EVO when they wouldn’t stay seated in the frame and fork. As a consequence, the hoses could rattle within the openings to the frame and fork until I managed to get them seated properly.
The rear brake hose also rattled within the CAAD12 Disc frame, but it was much louder. The length of the rear hose was very generous and looked to be the cause of the problem, so it really needed to be trimmed to suit the low handlebar height that I was using. For a cable-activated brake, this is a simple task that can be accomplished in a few minutes; a hydraulic hose requires a lot more time because the brake will have to be bled once the hose is re-attached.
Any comparison always begs the question, but in this instance, there is no obvious winner and loser. Nevertheless, after spending several weeks with the CAAD12 Disc Ultegra and SuperSix EVO Hi-MOD Disc Ultegra, I developed a preference. Initially, I favoured the SuperSix EVO, but as time passed I found myself gravitating towards the CAAD12.
Based on pure performance, there is nothing tangible to separate the two bikes. Rather, the distinctions are a matter of nuance. The SuperSix EVO had a smooth, refined feel to it, just like an expensive car. The CAAD12, by contrast, was rough around the edges, and ultimately, that’s what I really appreciated about the bike.
At the same time, I have to admit that I preferred the colour of the CAAD12. This may seem like a shallow distinction, but I count the presentation of a bike, and the way it resonates with the rider, as an important consideration.
Cannondale’s SAVE technology is all about extra compliance or “microsuspension” for the rear triangle of the bike.
Finally, there’s no denying the economical appeal of the CAAD12. Why spend more on a marginally lighter bike when that money could be used to upgrade the wheels? I won’t say that either bike is unrideable with the stock Aksium wheelset, but a set of lighter wheels will make a huge difference.
For those with ample resources, the SuperSix EVO Hi-MOD Disc will always be lighter than the CAAD12 Disc, though it’s hard to see how much appeal that idea will have given the significant weight penalty that is associated with disc brakes. Be that as it may, the SuperSix EVO Hi-MOD Disc has the prestige of being Cannondale’s finest carbon chassis. It’s also the bike that will be seen in the professional peloton for as long as the UCI continues its disc brake trial this year.
At this point, some readers may be wondering how the CAAD12 compares to other aluminium bikes. Unfortunately, I can’t offer any direct comparisons but the fact that the ride quality of the CAAD12 wasn’t very far removed from that of the SuperSix EVO Hi-MOD is quite significant.
In absolute terms, I’d classify the ride quality of the SuperSix EVO Hi-MOD Disc as reasonably compliant for a race bike, matching Scott’s Addict, Canyon’s third-generation Ultimate CF SLX, and Colnago’s C60. I’ve come to think of these as “rider’s bikes” that are well suited to any terrain with an edge in performance that should satisfy experienced road cyclists.
When shod with stock 25c tyres, the CAAD12 Disc sits just outside of this category, with a ride quality that essentially matches a variety of less compliant race bikes such as BH’s Ultralight EVO, Canyon’s Aeroad CF SLX, and Giant’s latest iteration for the TCR Advanced. That’s not to say that the CAAD12 is equal with these bikes in every other way, just that the amount of vibration and shock travelling through these bikes is roughly equivalent.
The idea that an aluminium bike could match the ride quality of a carbon bike might challenge popular and long-held opinions about the capabilities of the material, but research on the topic is clear: the material used to construct a bicycle frame has very little influence on ride quality. What is more important is the way the material is used along with the design and engineering of the final product.
The bicycle industry is somewhat unique in that is has come to embrace a variety of construction materials. The earliest bikes were made from wood but it wasn’t long before steel proved more robust. Alternative materials subsequently emerged, always with the promise of a variety of benefits, with the result that the modern bicycle has steadily improved.
It is in the last two decades, in particular, that there has been a marked increase in the sophistication of bicycle design and engineering. Our understanding of the various materials — steel, titanium, aluminium, carbon fibre, and even wood — has also grown in that time. There is no denying that each material has distinct physical and chemical properties, which in turn, give rise to specific strengths and weaknesses, but the bicycle industry has clearly demonstrated that it’s possible to exploit the former and compensate for the latter to great effect.
This is what Cannondale has done with the CAAD12 and SuperSix EVO Hi-MOD. Both bikes can be considered carefully honed race machines that promise to be robust and reliable, but by using different construction materials, Cannondale provides the consumer with what might best be described as a choice of personality.