Road Gear

From the pages of Velo: Performance Quantified

In the debut of VeloLab, our tech team put four aero road bikes to the test. Get the results from the lab and the road


Editor’s Note: In April 2011, we unveiled VeloLab, our in-depth bike and component testing program that combines objective, lab-based metrics with on-the-road evaluation. In the 14 months since, we’ve tested more than 20 bikes, from sub-$1500 budget road racers to the bikes of the WorldTour. We’ve even given four commuter rigs a spin. We’ve also recently put seatposts to the test and in the July 2012 issue, our tech team runs five aero wheelsets through the lab and over the road. The following cover story launched VeloLab with a look at the Ridley Noah, Cervélo S3 and others.

Torsional-stiffness testing. Aerodynamic-drag assessment. And expert analysis.
We present the VN Bike Lab’s inaugural review.

For the first time, VeloNews is undertaking extensive bike reviews. Here, we pit four cutting-edge aero bikes against each other in the lab and on the road.

In addition to riding each bike for at least 30 hours, we subjected each bike to two scientific tests performed by third-party facilities that specialize in such work. The end result is a balanced presentation of quantitative and qualitative information.

Our torsional stiffness test, co-designed and performed by Microbac Laboratories, Inc., will be constant throughout all our reviews going forward. The second test used here is specific to the aero category — aerodynamic drag testing at North Carolina’s A2 wind tunnel.

We rated each bike on five categories: scientific testing (30 points), ride quality (30 points), value (20 points), user friendliness (15 points), and weight (5 points). Each bike’s final accumulated score is not a grade — it’s simply an amalgamation of distinct characteristics. In other words, you should weigh segments of the ratings system in relation to your own preferences.

The Fast Four

The UCI upset the bike industry in 2000 when it imposed a minimum weight limit of 6.8 kilograms (14.9 pounds) on racing bikes. Some viewed it as a slap in the face to technology. But where some saw an obstacle, others saw opportunity. With the minimum weight fixed, creative engineers looked to improve aerodynamics, and the aero road bike category was born.

Tyler Hamilton helped put aero road bikes on the map in 2003 with his solo win at Liège-Bastogne-Liège aboard an aluminum Cervélo Soloist. These bikes were heavier than the lightest bikes available, but they could clearly be raced well in hilly races. Since then, many manufacturers have entered the fray, some so recently their models weren’t yet ready for our testing, such as the Scott F01.

After careful consideration, we chose the following four to test: Blue Competition Cycle’s AC1SL, Ridley’s Noah, Felt’s AR1 and Cervélo’s S3. All are equipped with racing in mind, without a compact crank or 28-tooth cassette in sight. And even if you don’t race, aero road bikes are still worth a look. Based on our wind tunnel data, an aero road bike can save up to 78 seconds over a standard road frame, with the same wheels, over 40km. Who says you can’t buy speed?

Meet The Testers

Caley Fretz is our youngest and fastest tester. As a Cat.1 racer, Caley is an unabashed elitist when it comes to compact cranks and any accessory intended to increase comfort and not speed. He puts bikes through their paces in training and in racing.

Nick Legan, on the other hand, has gone gray despite his relative youth, probably from too many alpine descents in the back of caravan vehicles working for teams such as CSC and RadioShack. He loves a compact crank and prefers long dirt climbs or gran fondos to criteriums.

As Caley and Nick are light, lanky riders, our editor in chief Ben Delaney was brought in for his heftier, ahem, sizeable, uh… expertise. And veteran technical writer Lennard Zinn — the man who literally wrote the books, plural, on bike maintenance — also weighs in.

Torsional Stiffness Results

The torsional stiffness test we co-developed with Microbac Laboratories, Inc. measures how a bike moves at three different points while subjected to a simulated pedaling force. Here’s how it works.

The front fork is fixed. The rear dropouts are mounted to a dummy axle that pivots on an eyebolt, allowing the rear of the bicycle to twist and move laterally. A chain is connected from the large chainring to the dummy rear axle to transfer the pedaling force through the rear triangle.

Dial indicators contacted the bike at the center of the drive crankarm’s face, at the top of the head tube and at the top of the seat tube. Two 50-pound dumbbell weights were hung on a spindle screwed into the left crank positioned horizontally forward and the values were recored on the three dial indicators.
—LENNARD ZINN

Ridley Noah

by Nick Legan

I wanted to love the Ridley Noah, I really did. We had one of those special moments about a year ago, as one lined up next to me at a local crit. My eyes met its swooping, aggressive lines and the yearning began; it was lust at first sight. And that rush of emotion proved to be equally fleeting once I got on one.

The Noah is one of the quickest bikes in the world. It blew away the rest in our torsional stiffness test, and though it didn’t fair as well in the wind tunnel, it was still tightly packed with the others, and leagues ahead of our baseline road bike.

So why was I disappointed? It’s a thoroughbred race bike, perhaps the purest race frame in our test, and I’m all about race bikes. I should have loved it. But I didn’t. The fact was that the bike was simply too stiff for my 145-pound frame.

Scientific Testing: 23 of 30 points
The Noah proved the stiffest of the bunch in the Microbac torsional stiffness lab test, 4.2 percent stiffer than the Blue, and 21.7 percent stiffer than the Felt. It didn’t fare as well in the wind tunnel. According to A2’s Mike Giraud, the standard down-tube placement of the shift cables may have had some negative effect on an otherwise fast frame. Likewise, the frame tubes, though aerodynamically shaped, are somewhat wide. This helped in stiffness, but harmed in aerodynamics.

Subjective Ride Quality: 20 of 30 points
The very attributes that gave the Noah such good lab scores — excellent torsional stiffness and a beefy tubeset — hurt it when the rubber met the road. I tried everything to make the bike more comfortable; swapping out tires and wheels, dropping tire pressure, swapping saddles, but to no avail. In the end the Noah gets a poor 5 of 10 points for comfort.

Acceleration was quite good, particularly under sprint loads. The Noah was not exceptionally light at 7.68kg (16.9 pounds), but had none of the sluggish feel often associated with heavier bikes and wheels. Nonetheless, sprinting on the flats left me with better sensations than accelerating mid-climb, earning 7 of 10 points for acceleration.

Handling was sharp and predictable, inspiring confidence descending switchbacks and leaning hard into fast corners. Though the handling was without any tangible flaws, we never achieved the sort of man-and-machine mind-meld tracking we have experienced with our favorite bikes; 8 of 10 for handling.

User Friendliness: 8 of 15 points
The Noah’s saddle-clamp mechanism is a chore, requiring a 13mm wrench and some serious patience to get everything set up correctly. The 4ZA brakes are weak and have a quick release similar to cantilevers, where releasing the cable means losing control over the brake entirely. Brakes are not a place to cut corners.

Value: 14 of 20 points
At $4,900, the Noah is nearly $2,000 cheaper than the next bike in this test, and almost half the price of the most expensive. Yet it still comes with a nearly complete SRAM Red group (barring the terrible brakes), bombproof Fulcrum Racing 5 wheels, and a stiff Deda cockpit. In all, it’s a very similar group to the much pricier Blue and Cervélo bikes. That said, the Noah’s ride quality and brake choice cut the value down.

Weight: 2 of 5 points
At 7.68kg (16.9 pounds), the Noah was the heaviest in our test by a decent margin, even without aerodynamic wheels.

You Can’t Handle The Truth! Or, Um, The Stiffness

Caley says the Ridley is too stiff. I say Caley is too skinny. It doesn’t take much to jostle his little 145-pound stick figure of a frame.

The Noah is a race bike. It is designed to go quickly. As Nick often points out, race bikes are single-purpose machines that don’t always perform perfectly as all-rounders. A race car and an SUV handle differently.

I believe Caley’s main beef is not the Noah’s torsional stiffness under pedaling load, but the ground-to-rider vibration transfer. After attacking him, I will defend him somewhat — the Noah does not damp the small but frequent bumps as much as you might like. This characteristic was most notable riding roads with a lot of surface grit; there, the handlebar and saddle vibrated noticeably. But when riding steady on clean roads, the Noah felt comfortable. Plus, when you stand up and sprint, the thing moves directly forward in no uncertain terms.

Bontrager sells a vibration-damping handlebar plug. The concept is simple — a little dead weight added to a handlebar kills the high frequency shaking. I believe a similar thing happened here with the bike. I weigh 50 pounds more than Caley, and the Noah felt just fine.

Bottom line? Go have a sandwich, Caley, and stop griping about a bike you can’t handle.
—BEN DELANEY

Felt AR1

by Caley Fretz

The AR got a taste of glory early, when a determined Will Frischkorn attacked from the gun on stage 3 of the 2008 Tour de France on a prototype frame. He made it all 208 kilometers to the finish with a small group and missed the win by less than a wheel. That heritage of the long breakaway lives on in the AR’s engineering. It was the most comfortable all-day ride in the test, perhaps at the expense of a little snap here and there. I’d pick the AR1 over any other on a day I plan to pull a Frischkorn.

Scientific Testing: 18 of 30 points
Overall, the AR1 was slightly less stiff than the Cervélo S3 in Microbac’s torsional stiffness test, putting it last in our group of four. However, deflection measured at the center of the bottom bracket was lower than the Cervélo and nearly on par with the ultra stiff Ridley. The AR1’s most remarkable feature in the wind tunnel was the stability of its drag numbers across various yaw angles. It wasn’t the fastest at any single yaw angle, but also didn’t have the wild swings between 0- and 10-degrees of yaw that the other three bikes did. There’s something to be said for consistency in crosswinds. A2’s Mike Giraud thinks the cause of this consistency may come down to the details. The bars and tape on the AR were a bit thicker than others, for example, which would increase drag at zero yaw but have less effect as the yaw angle increased.

Subjective Ride Quality: 22 of 30 points
While I might turn to the Ridley or Blue in a crit, due to their stiffness, I’d pick the Felt over both for a day-long breakaway. I found the AR1 to be the most comfortable bike in this test, particularly for long rides, earning a 9 of 10 for comfort.

Acceleration was a bit sluggish. The AR1 seemed to prefer keeping speed rather than gaining it, though that may have more to do with the somewhat hefty-but-aerodynamic Mavic Cosmic Carbone wheelset.

Handling was better in swooping corners than in tight ones. At 41.5cm, the AR’s chainstays are longest in the test by one centimeter, lengthening the wheelbase and slowing the handling.

User Friendliness: 12 of 15 points
It’s clear that Felt’s engineers did their homework, as the AR is as easy to wrench on as anything else out there. The component spec is solid, without any stinkers like on the Blue and Ridley. The only thing keeping the AR from a perfect score is its Dura-Ace Di2 drivetrain, which most consumers don’t have much experience installing or maintaining. Plus you have to plug it in, however infrequently.

Value: 15 of 20 points
As the most expensive bike in our test, without the best test scores, it would have been easy to knock plenty of points off here. However, much of that cost comes from the pricey Di2 electric group and Mavic’s Cosmic Carbone wheelset. You get what you pay for. In this particular case, that cost premium is coming from a top-of-the-line component spec, not exorbitant frame price. Nonetheless, the $9,000 price tag is staggering.

Weight: 3 of 5 points
Felt’s claimed weight of 15.4 pounds must be for a tiny frame with helium in the tires, because our 56cm weighed 16.6 pounds, making it the second heaviest bike in our test.

Blue AC1SL

by Nick Legan

After I returned from wrenching at the Ironman world championships in Kona last year (don’t hate me, my road racing roots are strong), I was eager to try a Blue. I had met several of the Blue Competition Cycles staff, and their enthusiasm for cycling and their bikes was contagious.

Blue shipped its first bike in 2004, and in a short time they’ve sponsored successful professional cycling teams, elite cyclocross racers and Ironman podium finishers.

Blue entered the aero road bike market last year with the AC1SL. With internal cable routing, an aero frame, fork and seatpost, and subtle graphics, the AC1SL is a sleek-looking machine. Happily, it rode much like it looked.

Scientific Testing: 24 of 30 points
As the second stiffest and second most aerodynamic, the Blue scored well in our scientific testing. The results speak for themselves.

Subjective Ride Quality: 21 of 30 points
The Blue was one of the most comfortable bikes in the test, which is amazing considering that it was the second stiffest in the test. I rode the bike up and down Colorado canyons and over frozen chip-seal roads in Indiana and I never felt abused. The supple Vittoria Open Corsa tires may have been the perfect rubber for this bike; more than almost anything else, tires and tire pressure can transform a bike, and this brought the comfort score to 9 out of 10 points.

The AC1SL is clearly designed for speed. Its stiff bottom bracket, BB30 cranks and light wheels meant that the Blue was ready to move. Strangely though, the AC1SL wasn’t overly eager to rocket into low-earth orbit. It took some coaxing to find cruising speed. The Blue made me think of the steady fast pace of a time trial instead of the violent thrashing of criterium sprints, meriting 7 of 10 points for acceleration.

Handling is where the Blue lost ground on the competition. Like a time trial bike, the AC1SL seemed to enjoy a straight line. It doesn’t lend itself to hard cornering, and it doesn’t turn in eagerly. Some riders may view its stability as a plus, but I found it a tad too slow for my liking. With a 72.5-degree head tube and 44mm of rake, it had the most trail of any bike in the test at 59mm; 5 of 10 points for handling.

User Friendliness: 10 of 15 points
The Blue has shift-cable housing stops on the top of the top tube. After that a bare cable (or Gore cable liner) runs through an internal frame guide that makes cable routing smooth and easily repeatable. The 25mm setback aero seatpost is easy to use, but I wasn’t able to get my saddle far enough forward for my normal position. (I run a zero-setback seatpost on my road bike.)

Value: 15 of 20 points
Blue made some good decisions on spec. They also made a mistake. All product managers try to save money without impacting the overall quality of the bike. Blue chose a Wipperman Connex chain and it was a good call. Shifting was great and I didn’t notice the substitution. The Aerus handlebar is nice, too. The TRP brakes, on the other hand, are a miss. They look great, and white is en vogue, but the lack of a real quick release and the weak return spring made for sub-par braking performance. For $8,000 you should expect a lot from the AC1SL. A $3,200 aero carbon frameset, Zipp carbon clinchers, SRAM Red shifting and BB30 cranks deliver on the investment, but the brakes don’t just slow the Blue down, they hold it back.

Weight: 5 of 5 points
As the lightest bike in our test, the Blue gets the maximum five points for weight. Not only did it beat the other three bikes on the scale, it came in at an impressive 6.8kg (14.9 pounds) without pedals or cages.

Cervelo S3

by Nick Legan

Cervélo created the aero road bike segment, and in popular opinion the brand has largely owned the category since. And though we made every attempt at objectivity, the truth is Caley and I hoped an underdog would emerge at the top of our test. But the Cervélo S3 is so compellingly good, we simply couldn’t ignore it. The S3 was launched in 2009 after Fabian Cancellara, Kristin Armstrong and others rode the bikes at the 2008 Olympic Games. Cervélo combined the slippery shapes of its aero frames with a more forgiving rear triangle, and the result is undeniable.

Scientific Testing: 25 of 30 points
While only the third stiffest in our torsional test, the Cervélo is the clear winner in the wind tunnel. Amazingly, with race wheels it’s actually faster at 20 degrees of yaw than it is head on.

Subjective Ride Quality: 27 of 30 points
Cervélo is no stranger to compliant rear triangles. The R3, and its miniscule seat stays, was fairly revolutionary when introduced. Incorporating a similar design into an aero bike yields a very comfortable ride. Even after three hours in the saddle, I was happy for more.

Proven by Thor Hushovd at the world road championships and Cam Meyer at the Tour Down Under, the S3 is a race bike, and its acceleration is great. It ranked third in torsional stiffness, but the S3 felt almost springy when I jumped hard.

Handling is where the Cervélo was the clear winner for me. Caley preferred the Felt, but agreed that the S3 is a beautiful bike to ride. When descending, I felt like a fool each time I reached for the brakes. The S3 is so confidence-inspiring I almost went out and bought a yellow jersey to wear when riding it. Even on rough or dirt roads, the S3 tracked perfectly. It would eagerly turn into a corner, but was never nervous. The geometry formula: parallel 73-degree head and seat tubes, with a 43mm fork offset — remember that if you ever start making bikes.

User Friendliness: 13 of 15 points
When I was a mechanic for Team CSC in 2006, I told Cervélo that they should make a zero-setback seatpost. I’ll say it again here: Cervélo needs a zero-setback option. I hate having my saddle shoved all the way forward on its rails.

Some mechanics have complained about the top-tube routing of the shifter cables. The system is easy to set up and works well, but it is easy to kink a cable with the hard angle the cable must make to enter the frame.

Lastly, the Rotor crankarms are very square and offer little ankle clearance. Initially I hit my heels more than I liked, but I worked around it.

Value: 17 of 20 points
Value is the hardest thing to judge, because it is highly personal. For $6,600, the Cervélo is expensive. But is it worth it? I feel it is. With full SRAM Red shifting and brakes, Rotor crank, 3T bar and stem and a fi’zi:k Arione saddle with braided carbon rails, there are no house brands in sight. The Fulcrum Racing 7 wheels rode well and the Vittoria Rubino Pros are good all-around tires. I think that selling the S3 with good training wheels makes sense. Most racers are far pickier when it comes to race wheels than they are regarding their training wheels.

Weight: 4 of 5 points
Amazingly, even with Fulcrum Racing 7 wheels, the S3 was the second lightest in our group at 7.130 kilograms (15.72 pounds) without pedals.

Results

Cervélo winning here is a bit like the prom queen getting into Harvard; it just kills you inside. Stop being so damn good!

Frankly, we didn’t want to see the Cervélo win; it was too predictable. But, despite our best efforts to prove the contrary, there was no denying that the S3 is a great bike. Even before the wind tunnel numbers came back, the S3 blew us away with its fantastic ride quality, solid build and obvious attention to detail. When it proved the fastest at A2, the deal was sealed.

Fact is, every bike here is likely faster than yours. Whether you’re racing or just want to beat up on your buddies, an aero road bike can provide real gains over your current round-tube ride.

Racer-boy Caley Fretz would happily motor on any of these bikes, attacking early and often. Wool-wearing Nick Legan prefers a more traditional aesthetic for his personal bikes, and isn’t as eager when it comes to spending his hard-earned coin.

The Ridley Noah was fourth in our test, but it’s not a bad bike. Its knock-your teeth-out stiffness and quick handling could make it perfect for a bigger crit rider.

The Felt, as proven last year by Garmin riders, is a capable all-day bike. It placed third in our test largely due to low torsional stiffness scores and a third place in the wind tunnel test.

As an underdog coming into this test, the Blue surprised and impressed us. We didn’t expect such excellent aerodynamics and ride quality to come out of the relatively small Georgia company.

The Cervélo S3 is a brilliant machine that thoroughly thrashed its competition. The fact that our diverse testers both fell in love with it is a testament to its versatility. Interestingly, the torsional test didn’t correlate much with our overall opinion of a bike. We did perceive the Ridley to be the stiffest before we took it into the lab. But stiffer — whether perceived or otherwise — did not always mean better.

One takeaway: stiffness is often too highly touted. Ride quality, and the role stiffness plays within it, is more complex than a single test can tell us.

Aero road frames seem to be the next frontier, and for that perhaps we have the UCI’s weight limit to thank. While that limit affects only pro cyclists, the industry’s response to it, in changing their focus from weight to aerodynamics and ride quality, has benefited everyone. After spending 150 hours on these bikes, we can confidently say that the downsides to going aero every day are few and far between.