Cannondale enjoyed some great success in years past, under riders like Chrissie Wellington and Mirinda Carfrae (Carfrae used to ride Cannondale, though she currently rides for Felt). But in recent years, Cannondale, and its marquis tri bike, have fallen out of favor. Heather Jackson has been riding hers successfully, but with the amazing development of bikes across the industry, the Slice has really seemed like yesterday's news. And now, it officially is - the 2015 Slice is here, and although it was unveiled much earlier this year, and even shown on Cannondale's own site as the "current" model, Cannondale's "official" launch wasn't until now, at the 2014 Ironman Hawaii World Championships.
Originally, I was a bit confused; Cannondale insisted that this is a NON-UCI bike, meaning that it wouldn't follow the frame-construction rules of Pro Tour bikes. Usually, this means seeing something like the Felt IA or Specialized Shiv, but when we look at the 2015 Slice, everything looks very ... well ... ordinary. None of the frame shapes look like they are out-of-bounds for the UCI, and there aren't any missing frame members as we've seen on bikes like the Falco or Dimond. It's got a relatively shallow-chord fork, down tube, and seat tube, which are within the 3-to-1 UCI rule, and under the 80mm-deep UCI limit.
So what's "illegal" about this bike? According to Cannondale, just the rear stays. Yep, the rearmost frame members, which contribute the least frontal area (and drag) of all, in an area where airflow is already so disturbed that any differences here are likely to be relatively small. Instead of going hog-wild on a sweet tri-specific design, Cannondale elected ONLY to make the stays thinner. Huh? To me, this makes absolutely no sense from a design perspective.
From this view, you can see the Slice is behind the times, aerodynamically speaking
Cannondale's explanation for the frame's design is that for them, the aerodynamics of the bike was not the top priority, and they openly admit that this isn't the most aero bike on the market today. Instead, they insist that by focusing on comfort, weight, stiffness, and fit, the bike is actually faster than more aerodynamic bikes on the market today. I have an incredibly hard time believing this. For example, they mention that those super thin seat stays, which were primarily designed for compliance, give the frame double the compliance of other aero frames. However, when they show us the actual numbers, it turns out we're only talking about a deflection difference of about 1mm. That's less than the difference you'll get by letting about 10psi of air from your tires. Comfort on a tri bike has much more to do with the right fit (which you can achieve on any of the good modern bikes from Felt, Trek, Specialized, Scott, Cervelo, etc), the right saddle, and the right tire and tire pressure. Frame compliance is just not an important issue from where I'm sitting.
In other words, the comfort and stiffness issues are a bit of a red herring. Cannondale is taking a bike that is measurably slower in terms of aerodynamics, but doesn't have any measurements to show that a more compliant or lighter bike will actually make up for that loss. And I believe this is because those features don't make up for the aero loss. For example, Cannondale insists that one redeeming feature of this bike is its low weight. On their website description, that's the first point they make about their new rig - that it's light. They mention this before saying anything about aerodynamics. And that, in my mind, is an example where they've mixed up their priorities. Don't get me wrong, I'm all about lightweight parts, and I think it's cool that there's a manufacturer who hasn't forgotten about weight, but not when it means a compromise to aerodynamics. And there are plenty of good articles that demonstrate the importance of aerodynamics over weight (when you have to choose one or the other). Moreover, when you can build a 15-pound Cervelo P5 (including a disc wheel), it's pretty much game over for a less-aero frame that might boast a minor weight savings. And for almost every course on the planet, that would be true at weights much higher than 15 pounds. But if you're really focused on weight, you still don't have to give up aero - as we did with Project Liberty. Insisting that aerodynamics is the enemy of features like weight and comfort is a false dichotomy. There are very comfortable, very light, and very aerodynamic bikes out there, and the top manufacturers are doing a great job demonstrating that you CAN have it all. I categorically disagree with Cannondale's take on the issue.
Brakes are direct-mount only; no aftermarket options available for those who might want to clean up the aerodynamics.
In other aerodynamic news, the bike is ONLY built to accept Shimano direct-mount brakes. That means no chance to clean up the front cable routing, at least until FSA releases their direct-mount centerpull (or someone else does ... hint hint). But Cannondale did make a good move from the original Slice by moving the shifter cable routing to the top tube rather than the down tube. However, aft of the top tube cable ports, there aren't any bosses for the now industry-standard storage mounts. So you'll have to resort to unsightly (and unaero) Velcro straps if you want a bento-type box. You won't be seeing anything quite this clean on the new Slice.
Another thing that really bugs me is the enormous gap between the trailing edge of the front wheel and the fork crown/head tube/down tube complex. In recent years, EVERY big-name manufacturer with wind tunnel chops has moved to bikes that eliminate this gap as much as possible, citing the aerodynamic benefits of such a design. It started with Cervelo's P4, and has proliferated through designs by Scott, Specialized, Felt, Trek, and MANY more. To see a tri bike, particularly one that claims to eschew the UCI rules, NOT doing this in such a critical area, is very disappointing. Again, Cannondale says that dropping the down tube would have compromised some of its comfort or weight numbers, which I again have a hard time believing.
To be fair, there are some things I really DO like about the bike. The Cannondale-invented BB30 has always been my favorite standard, and the Slice continues to use it. Higher end models are even equipped with Cannondale's awesome SiSL2 crank, one of the very lightest options out there. The front end options (other than the brake) are left up to the user, by offering a standard 1-1/8" steerer tube to which the user can attach any stem and aerobar. There are more and more good options out there in terms of both stems and bars, so the need for integrated solutions up front is growing smaller and smaller, and standard interfaces are a great option, making fit and adjustment much more straightforward.
In the end, the new Slice seems to be neither here nor there; it's not a thoroughbred triathlon machine like the Felt IA or Specialized Shiv, and it fails to capitalize on the UCI market as well, like the amazing Cervelo P2. Its aerodynamic pedigree fails to impress, and the lack of convincing data to show that it is actually fast makes me think there are better options out there. If the year were 2004, I might describe the bike as cutting-edge. But this is 2014, and the bike seems quite dated. If the base model were $1500, I'd call it a good deal. But the base model with Shimano 105 costs $2710, and when you can get the much more desirable Cervelo P2 with the same group for $2500 ... well, then I'd have to recommend the Cervelo. Cannondale took a big gamble trying to tell a story about a tri bike that isn't trying to be at the cutting edge of aero, but ultimately I don't think that was a good move, and I don't think it will resonate with consumers. Of course, the market will make the ultimate decision, so I could well be proven wrong.
Editor's Note: to be clear, Cannondale doesn't mean to convey that it has ignored aerodynamics, just prioritized them differently than other companies. They believe that this bike will, in practice, be a more enjoyable and faster bike for what they call "real world triathletes." I simply disagree with their assessment of priorities, and the conclusions they draw about what this bike is and what it represents. Readers are encouraged to draw their own conclusions.