Cervelo R3, Part I

December 22, 2011 by  
Filed under Machine

The world changed when the bike industry moved to carbon fiber for fabricating most high-end bicycle frames. The shifts were myriad. Many of the bigger companies began employing engineers for the first time ever. Most of the bigger companies either started producing what was effectively their own tubing for the first time or had someone else produce tubing for them, to their spec. The way marketing materials were written changed as they sought to attempt to both hide what materials they used even as they tried to pitch the objective advantage their materials offered the buyer.

It was a helluva change.

Think back. For those of you who went through a steel frame or three before buying a first carbon fiber frame, you’ll recall that bike companies, as well as small framebuilders, all touted just whose tubing they used. So much so, they put a sticker on the seat tube announcing just what they used. It was anything other than a secret.

How companies like Trek, Specialized, Felt, Zipp and others deal with their materials is very different. They effectively create their own alloy by buying carbon fiber from different mills and blending it within their frames as they see fit. To make matters worse, when you try to talk to the folks charged with media relations, one will talk about sourcing from Toray (one of the big mills), while another will talk about modulus and tell you the source doesn’t matter, while another will say modulus doesn’t matter, compaction and resin are the issues. It’s maddening.

 The R3′s tiny seatstays play a big roll in the bike’s ride quality; it’s a design feature that has been widely copied.

Without the benefit of that tubing sticker, bike companies go to great lengths to check out the work of their competitors. They have two primary tools at their disposal. The first is the saw. They will cut frames apart to see what’s inside. They can get a look at exactly what fibers are being used. The other method involves baking. A frame can be put in an oven and baked apart; all you have to do is exceed the resin’s cure temperature. What it yields is a bunch of sheets of carbon fiber. You can see the exact shape and position of ever sheet used. Unfortunately, this method of investigation comes with a downside. You can’t tell what any of the sheets of fiber were; there’s no telling if they were intermediate modulus, high modulus or ultra-high modulus.

I’ve long admired Cervelo’s work, even if I have found some of their designs less than attractive, or comfortable. The SLC-SL remains one of the most unpleasant to ride bikes I’ve ever swung a leg over. But with a pair of Zipps, it was a very fast bike. I found myself constantly scrubbing speed inside the group. What was more impressive about the bike was its torsional stiffness. The bike, despite its aerodynamic-profile tubes, didn’t twist to any appreciable degree. I’ve been on many similarly shaped frames that would twist under a hard acceleration even while firmly ensconced in the saddle.

What elevated my regard for Cervelo’s work a few years ago came not from anything their PR people told me, not from a big win aboard one of their bikes and certainly not from some bike magazine review. An engineer for one of their competitors had baked apart a frame and told me of the sophisticated layup they were using. That there were places where he’d have loved to know what fiber they were using to achieve the stiffness and strength they managed at the bottom bracket. The frame was too light, too stiff and too strong to make the answer easy or obvious.

Cervelo touts its “squoval” tubing shape, which is a cross between oval and square which they say is better able to withstand twisting forces.

This guy was unimpressed with some of the work he was seeing from the big three. He talked about how you’d see stacks of fiber maybe five or 10 sheets thick grabbed and placed. Maybe with decent care, maybe not. In his view it was the downside of having to achieve the production numbers they needed. He said with Cervelo you could tell that each sheet was placed individually. You can’t make frames as quickly that way, he told me. But they break less often and usually offer the rider better quality and improved stiffness because the sheets are perfectly oriented for their intended role.

The conversation (actually, I’ve had a similar conversation with two other engineers not employed by the Canadians) made me sit up and take note of Cervelo in a fresh way. It also gave me a new perspective on my previous experience with the SLC-SL. Maybe some of that incredible stiffness was due to great care. Huh.

Since then, I’ve ridden every Cervelo I can get my hands on. I’ve had a day on the S5 (I wrote about that here) and a couple of days on the old R3 SL. This spring Cervelo sent me the new R3. I rode it through the spring, summer and into the fall.

I didn’t want to send it back.

Tomorrow: Part II

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The Cannondale SuperSix EVO

May 15, 2011 by  
Filed under Machine

Brand identity is a funny thing. When I was a kid, Ford represented the car my dad drove. Later, it came to stand for an American car I wouldn’t own even if you gave it to me. More recently it has come to symbolize the very best in how a company can reinvent itself and survive under its own steam. At least, that’s how I see them.

Cannondale has had a similarly curious arc. There was a time when the brand made accessories, not bikes; they were a competitor to Rhode Gear, not Trek. And while large-diameter tubing aluminum bikes weren’t solely their domain, the company named for a train station achieved greater market penetration than Klein ever did. In the 1990s, I recall the company as being a repository for talent, fresh ideas and ambitious marketing. Actually, the company wasn’t just ambitious in its marketing, it was as ambitious as any bike company had ever been.

Then came motorcycles and the bankruptcy. For a while, the brand felt like damaged goods and though I was a fan, I wasn’t sure they’d survive with their full reputation intact.

Though Cannondale has stayed at the forefront of aluminum development and construction, the Connecticut company was by any standard late to the carbon fiber game. The Six13 may have used an innovative method to join carbon fiber to aluminum, but nothing could change that a bike featuring three carbon fiber main tubes joined to an aluminum head tube and rear triangle was an idea that dated to the first Bush presidency.

With the SuperSix, Cannondale got into the carbon fiber game in a serious way. It had the hallmarks found in its competitors’ bikes: It was light, stiff and reasonably lively feeling. However, it wasn’t a particularly special bike. The problem wasn’t so much Cannondale as it was the market. By 2008, there was a near glut of really good carbon fiber bikes on the market. There was a much shorter list of truly extraordinary bikes.

It wasn’t too long ago that in purchasing a carbon fiber bike you had to choose between stiff and light. The industry has essentially solved that problem. So what separates the good bikes from the great ones? Road feel. The knock against most magazines’ reviews of bikes is that the reviewer always credits the bike with being “torsionally stiff and vertically compliant.”

Even for riders who haven’t ridden a dozen different bikes, there is widespread acceptance that as bikes gain stiffness in torsion they lose flex—compliance—in every other dimension. However, the quest for torsional stiffness combined with vertical compliance isn’t quite as mythical as the unicorn.

For those of you who have followed the development of the Specialized Tarmac, it is the perfect example of how a bike that is stiff in torsion can be tuned to take some of the sting out of the rear triangle. The original Tarmac SL was a very good bike. Two years later Specialized introduced the Tarmac SL2. It was stiffer in every direction, but it was also livelier feeling. That rear end, though, was a bit brutal on long rides. Two years after its introduction the company followed up with the Tarmac SL3. The front triangle remained unchanged, but the rear triangle was redesigned with both new tube profiles and a new lay-up. Ride the two bikes over the same roads and you’ll quickly feel how the rear end doesn’t chatter as much. It feels as if you let 5 psi out of the rear tire.

Back to Cannondale.

I’ve just spent two days riding the brand-spankin’-new SuperSix EVO. This bike is to the previous SuperSix what the Bugatti Veyron is to the Chevy Camaro.

The bike boasts some impressive numbers, such as a normalized weight of 695 grams. It has scores the highest stiffness-to-weight ratio ever recorded: 142 Nm/deg/kg. That’s more than 15 percent higher than the Specialized Tarmac SL3 and more than 40 percent higher than the Trek Madone 6 SSL.

We can talk numbers all day long, but based on my experience, there seems to be a tipping point in ride quality when you near the 900g mark for a frame. I can’t claim this is true for every bike out there, but my A-list of bikes I’ve ridden, which includes the Tarmac SL3, the Felt F1, F2 and Z1 and Cervelo R3 SL, were all at or below 900g.

My sense isn’t that the weight is the issue. Weight is just the canary in the coal mine. What gives these bikes their lively ride quality is the incredible compaction achieved in their construction. Tap a tube with your fingernail and you’ll get a near-metallic-sounding “tink.”

The SuperSix EVO possesses these same qualities. And like the Felt F1, it employs hollow carbon fiber dropouts, which both reduce weight and increase the lively feel of the rear triangle without increasing stiffness. What helps to separate the SuperSix EVO from other similar bikes is the fact that the chainstays have been flattened along the horizontal plane once they clear the chainrings.

Cannondale says it didn’t set out to make the lightest bike, the stiffest bike, the most aero bike or even the smoothest-feeling bike. What they came up with is an incredible blend of those qualities. They say they wanted the most efficient bike out there. It’s hard to say they’ve created the most efficient bike on the market, but it’s easy to say it’s among the most efficient. I haven’t previously ridden a bike that offered as much torsional stiffness while feeling as smooth over rough pavement.

With the introduction of the SuperSix EVO Cannondale has effectively reinvented itself as a bike company. This is an extraordinarily sophisticated bike, the result of three years of work … and it shows.

I’m looking forward to getting one of these to review next month. In the meantime, for even more details you can check out my piece for peloton magazine.

 

 

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