High End Road Bikes

Introduction: Aerodynamics and Friction Losses
AERODYNAMICS have preoccupied bicycle designers since the early part of this century. The most advanced bicycles today are deployed in track racing. The recently unveiled SB II, or Superbike II, has a lightweight carbon-fiber frame. It also has a range of aerodynamic design elements. Similar features are incorporated into bicycles for some road-racing events in which Lance Armstrong competes.
As the bicycle and its rider move along the road, the air exerts a force that increases sharply with speed. The force is due to friction between the air and the exposed surfaces of the rider and bicycle. At high speed, this drag force can be the most importance source of resistance, and with a wind blowing, it can also lead to significant side forces.
The aerodynamic forces on any vehicle come primarily from differences in "pressure" viscous shearing stresses. Both types of forces ("pressure" drag and "friction drag") arise because all real fluids have "viscosity".
Viscosity is a basic property of fluids. The viscosity of air is very small, but it is not negligible. Frictional drag comes from friction between the air flow and the surfaces exposed to the air flow. This friction arises because air (and other fluids) has viscosity. Viscosity is associated with the ability of a fluid to flow freely. For example, honey has about 100 times the viscosity of water, and it is obvious that the two fluids flow differently, and that it takes much greater force to stir honey than water. The frictional drag also depends on the Reynolds number, because the flow is laminar at low Reynolds numbers, and turbulent at high Reynolds numbers. Pressure drag comes from the the eddying motions that are set up in air by the passage of the rider. This part of the flow is called the wake, and it is similar to the flow left behind a passing boat. It is generally not a strong function of Reynolds number. There is an important connection between velocity and pressure, expressed in Bernoulli's equation (for inviscid flows), and between velocity and cross-sectional area, expressed in the continuity equation
There are also two kinds of bodies: streamlined bodies, bluff bodies. A streamlined body looks like a fish, or an airfoil, and the streamlines go smoothly around the body A bluff body looks like a brick, or a cylinder, and the streamlines break away whenever a sharp change in direction occurs. For streamlined bodies, the frictional drag is the dominant source of air resistance. For a bluff body, the dominant source of drag is the pressure drag. It is always true that, for a given frontal area and speed, a streamlined body will have a lower air resistance than a bluff body.
The biggest difference between streamlined and bluff bodies is that in streamlined flow, the regions where losses occur are inside and wakes that remain reasonably thin, whereas in bluff bodies, adverse pressure gradients cause the boundary layers to separate, which creates a large wake filled with energetic eddies which dissipate a great deal of mechanical energy and thereby increase the drag.
Parts of a rider and bicycle combination act like a streamlined body, whereas other parts behave like a bluff body. By understanding some basic aerodynamic principles, it becomes possible to identify these components, understand the magnitude of their different contributions to the overall drag, and see how we can reduce the overall drag by altering the shape of the component parts.

With victories from cobblestone Tour stages to mass sprints to the World Championships, the S3 is Thor Hushovd's favorite bike. Aero road bikes seem to be a "trend" nowadays, but for Cervélo and its riders, they are the essence of what we do. They offer the advantages of reduced drag while preserving everything else you expect in a good road bike. Not an easy balance to strike, but 15 years of experience doing that certainly helps. The S3 is part of the S-series, our all-round models equally at home in fast solos and hilly terrain. With just a few grams more than the R-series, it offers a true aero advantage. Experience: 1. Reduced aero drag to save energy.
2. A low geometry to put yourself in an aero position.
3. Proper road bike performance, because an aero focus shouldn't compromise lightness, BB/torsional stiffness or comfort.

MAIN TECHNOLOGIES
- Oversized bottom bracket area
- Smartwall for Carbon
- TrueAero shapes
- S3 aero seatstays
- Aero chainstays
- Aero headtube
- Internal Cable Stops ICS3

Upgrades from S2
Lighter
Better aerodynamics (seatstays, chainstays)
Even more comfortable (seatstays)

Excerpt from MIT Press:

Bicycling Science, 3rd Edition
David Gordon Wilson

Table of Contents and Sample Chapters

The bicycle is almost unique among human-powered machines in that it uses human muscles in a near-optimum way. This new edition of the bible of bicycle builders and bicyclists provides just about everything you could want to know about the history of bicycles, how human beings propel them, what makes them go faster, and what keeps them from going even faster. The scientific and engineering information is of interest not only to designers and builders of bicycles and other human-powered vehicles but also to competitive cyclists, bicycle commuters, and recreational cyclists.

The third edition begins with a brief history of bicycles and bicycling that demolishes many widespread myths. This edition includes information on recent experiments and achievements in human-powered transportation, including the "ultimate human- powered vehicle," in which a supine rider in a streamlined enclosure steers by looking at a television screen connected to a small camera in the nose, reaching speeds of around 80 miles per hour. It contains completely new chapters on aerodynamics, unusual human-powered machines for use on land and in water and air, human physiology, and the future of bicycling. This edition also provides updated information on rolling drag, transmission of power from rider to wheels, braking, heat management, steering and stability, power and speed, and materials. It contains many new illustrations.

About the Author

David Gordon Wilson is Professor of Mechanical Engineering Emeritus at the Massachusetts Institute of Technology. He is the coauthor of the first two editions of Bicycling Science and was the editor of the journal Human Power from 1994 to 2002.

The Super-9 disc excels in races won on full-throttle power. Intended for time trials, track racing, and the occasional Tour de France prologue, the Super-9 is stiffer than our 900 disc and matches the Sub-9's remarkable ability to generate forward lift when paired with our Tangente tire.

The Super-9 borrows from the perimeter shape that makes the Sub-9 so fast it can actually generate forward lift. But in place of the Sub-9's toroidal bulge, the Super-9 stays flat from its widest point all the way to the hub. As a result, the Super-9 is much stiffer
and more responsive than the Sub-9, but just as aerodynamic - even with 23mm tires.

The Super-9's hub features the stiff 17mm axles of the 188 road hub along with adjustable bearing preload with the industry's only aero preload nut. The standard version of the Super-9 weighs less than 1,000 grams and is convertible between road and track setups.

The Super-9 has claimed multiple world TT championships and Tour stages, not to mention the bike split of the fourth-fastest Iron-distance triathlon performance of all time.

LOOK launchs a new era in high performance in the 695: a frame offering unequalled cycling precision thanks to the integration of the stem, the headset, the fork and an exceptional accelleration with the ZED crankset.

The 695 puts the CFD (Continuous Fibre Design) in application : the shape of the tubes is studied so that the carbon fibres work along the best axis, optimizing their mechanical performance.
The ZED 2 crankset, the frame's nerve centre, is the culmination of 5 years of research and tests with our athletes at the 2008 Beijing Olympics. It brings a new world record in the weight/rigidity ratio.

Disc brake equipped alloy framed F65X

Felt surprised us, though, with all-new alloy 'cross bikes, too. In contrast to the outgoing F1X, the new frames still with 100 percent 7005 aluminum construction, stays and all. Additional features include 1 1/8-to-1 1/2in tapered front ends, carbon and alloy tapered forks to match, true BB30 bottom brackets, hydroformed "shoulder friendly" top tubes, forged alloy dropouts, and lighter weights than the old F1X at 1,434g as compared to 1,585g.

The US$1,999 F55X will sit at the top of the alloy 'cross bike heap with a Shimano Ultegra 6700 transmission, an FSA Energy BB30 crankset, Fulcrum Racing 7 CX wheels, and Tektro wide-profile cantilevers. Riders on more of a budget may find themselves looking instead at the F75X, which uses the same frameset but Shimano 105 bits, an FSA Omega BB30 crankset, Felt CXR3 Cyclocross wheels, and Tektro wide-profile cantilevers for US$1,449.

Felt unfortunately didn't include the disc-equipped F2X show bike into the '12 range, saying pro riders were logically still awaiting proper full hydraulic systems from component manufacturers to really pull the trigger. That being said, 'cross fans looking to run disc brakes can instead opt for the F65X with its disc-specific alloy 'cross frame and fork - similar to that of the F55X but with 135mm rear hub spacing and dedicated caliper fittings) - outfitted with Avid BB5 brakes, Felt CXR3 Cyclocross wheels, SRAM Apex DoubleTap levers, a custom SRAM S300 BB30 crankset, and SRAM Rival derailleurs.

Though the US$1,999 F55X will obviously be a bit heavier than a rim brake equivalent, Felt has minimized the impact somewhat by speccing lighter Ashima 160/140mm front/rear stainless steel brake rotors with more aggressive cutouts and a 1.6mm thickness. Claimed weight on the front is just 85g while the rear is only 68g.

Wrapping up the '12 Felt 'cross range is the US$1,299 singlespeed Breed, which gets similar upgrades as the rest of the alloy frames but will rear-entry horizontal dropouts, a trick rear thru-axle rear hub that requires just a single 15mm wrench for installation and removal, and a clever BEERNuts tool that attaches to the water bottle bolts.

If SRAM is the performance-value leader and Shimano is what others are measured against, Campagnolo can always be depended on to be the most classy component group on road, no matter the category. It's newest Athena group, which serves as the entry point to 11-speed, is no exception.

Any Campag-phile will be absolutely tickled with the performance and aesthetic of the new Athena. Whether it's an update to a vintage bike, picked by the connoisseur on a budget, or for a winter bike as supplement to the new Super Record race package, the rider preferring Campagnolo will not be disappointed. Athena's performance in the latter case for someone with two bikes and a higher-level 11-speed group is possibly its most impressive feat, as it generally performs as well as any of Campy's other 11-speed groups.

Campagnolo 11-speed, generally speaking

The following performance statements can blanket all of Campagnolo 11-speed groups and hold true for Athena. The ErgoPower lever shape paired with Campy's dual compound hood is the most comfortable lever on the market, though some may not prefer the thumb operated cable release lever. Small hands seem to have a particular problem reaching the lever. Campy accomidates extra-large hands through the use of a body shim that increases lever reach by 8-degrees.

While Campy's brakeset, equipped with a single-pivot rear design, previously came in a clear third behind SRAM and Shimano with regards to power, 2011 brings the option of a dual-pivot rear brake for all of its groups from Super Record to Veloce, which should significantly close the gap.

What the Campy single-pivot rear brakeset lacks in power, however, it makes up with some of the best modulation on the market. Newer riders will particularly benefit from the single-pivot rear brake's aversion to locking even under panic stopping. The attributes will definitely also benefit those up through the professional ranks in wet conditions, especially. It should be noted that the latest Ergopower lever design does offer more power to the dual pivot front and single pivot rear calipers, should you be upgrading from the older style lever. Ultimately with a choice of a single- or dual-pivot brake in 2011, riders will have to decide which suits their riding style and conditions best. As an example, we expect the new dual-pivot brakes to be used in the mountainous grand tours, while the single-pivot brakes surely make sense for the slippery cobbled classics.

Campy 's rear dual-pivot Athena brake costs just £6.50 more than the dual-pivot front and single pivot rear option.

There's no getting around the fact that 11-speed is more finicky to precise adjustment than Campy's previous 10-speed groups and much more testy than Shimano or SRAM's offerings, with the latter seeming the most robust in our experience. After our experiences on the road - the group requires weekly fine-tuning and attention to stay in top working condition - we cannot recommend 11-speed for cyclo-cross. This is despite the benefits the lever's shape and function would have off-road. Campy makes the Centaur and Veloce groups with the same lever shape in 10-speed, thus making them prime options for off-road use in the autumn.

Athena; goddess of grace

The performances of Campy groups are best described as graceful, and this holds true for Athena. The lever action is light and the rubberised rear derailleur pulleys and rub guards within the front derailleur cage keep things very quiet. A key attribute is that Campy doesn't slam into gear like SRAM, which depending on your purpose can be a good or bad thing.

Ultimately, riding Athena offers the same riding experience as any of Campy's 11-speed groups. In fact, you'd be hard pressed to differentiate between Athena and Record, performance wise, without looking down at the components while riding or a scale. Campagnolo absolutely rivals SRAM in terms of the consistency of performance throughout the range of their groups.

Timeless looks

While Campy's carbon-infused Super Record, Record and Chorus groups are super sexy, there's still something to be said for the way Athena's high-gloss polished aluminium parts pop off a bike - especially an elegant steel or titanium model.

The finish seems to be as cared after at that found on Campy's higher-level groups, and held up admirably over the course of our six-month test.

The greatest benefits

We've already mentioned the superb ergonomics of Campagnolo's ErgoPower levers, and the excellent modulation offered by the brakes. The final - big deal - performance attribute worth calling attention to that's found in the Athena group is Campy's Ultra-Torque semi-axle crank and bottom bracket design. While the forged aluminium Athena crankarms are noticeably more flexible than most of the carbon, and just about all of the hollow aluminium options on the market, they're also some of the narrowest - with external BB cups - on the market, as the Q-Factor measures just 145.5mm.

Our test rider weighs 150lbs and can be classified as an all-round rider - neither a wispy climber, nor a ring-bending sprinter - and while the crankarms comparative lack of stiffness was noticeable, it wasn't a huge negative blemish on the group. Given the option between maximal stiffness and a narrow Q (with adequate stiffness) we'd pick the latter and that seems to be right where Athena falls. The crank's shifting performance and overall stiffness is aided by the high-quality 3.5mm-thick machined chainrings, though nothing currently on the market can compare to the stiffness of Shimano's two-piece Dura-Ace and Ultegra large chainrings.

Finally, it's worth noting that the Athena rear derailleur will accept up to a 12-29-tooth 11-speed cassette, which can be paired with a compact version (CT) of the crank for those needing mountain goat-like gearing without the stigma or lesser aesthetic of a triple.

Testing, 1,2

Our Athena group test spanned three seasons: winter, spring and summer. We rode our test group in the mountains and on the flats and through rain, snow and sun.

We tested Athena with its optional carbon wrapped levers, which adds around £25 to the all-alloy group price, but without the carbon crank, which saves £150. A full 8-piece alloy group costs in the region of £800 and the carbon group (with carbon wrapped levers and carbon crankset costs £975: both group prices can vary by £50 due to front derailleur, dual- or single-pivot rear brake, bottom bracket size and cassette options.

While over the course of our test the group needed considerable tuning attention, it did not suffer any major failures; the chain shows some wear, though falls within reasonable stretch parameters, and the brake pads have held up very well.

One of the biggest issues we had with the group was upon installation. We did not have a Campagnolo 11-speed chain tool, which is required to properly install the chain. In the end we went to a local shop to borrow a tool. Campagnolo's own chain tool costs upwards of £130 and adds considerable expense to the group, should you enjoy working on your own bike as we do.

Luckily, Park Tool offers a compatible CT-11 chain tool for £25 and Pedro's offers the Tutto Multi-chain tool for around £60, which fits all 1/8in and 3/32in single and 8-, 9-, 10- and 11-multi-speed chains currently available.

In the end, despite any of the issues we've addressed here, we must say bravo to Campagnolo for their work on Athena. If you like Campagnolo's style of performance, this reasonably priced group will not let you down.

With its 28mm tyres, V-brakes, upright riding position and trekking drivetrain, the Sirrus Comp is close to the classic hybrid. It doesn't have a road bike feel, nor an off-road ethos. Ironically, it's not specialised. For new cyclists or those not owning several bikes, that's its strength.

The aluminium frame is oversized or flattened where you'd expect, maximising stiffness, strength and weld area on the one hand and any (that is, little) vertical compliance on the other. The curved top tube's neat look is undisturbed by a rear brake cable, since that runs internally.

But what's most significant about the top tube is how short it is. A lot of Specialized bikes have a shorter reach than their rivals, and this is no exception. You're really sat up. New cyclists seem to like this more, and it's %uFB01ne around town because you're looking up and around rather than down at the tarmac. If it doesn't appeal, look to buy the next size up.

Comfort is good even when you're sitting upright. Curved seatstays - Specialized call them hourglass - may help a bit and the fairly long chainstays certainly do. Because you're not sitting as close to the rear axle you're distanced a little more from bumps and vibration. It's like the difference between sitting in the middle of a bus and over the back wheels.

It helps that a carbon seat-post is specialized. The fork is composite too: a FACT carbon one with Specialized's Zertz inserts. These are rubbery plastic thingummies that sit in a hollow going all the way through the fork. Do they make a difference? Possibly, possibly not. But they don't make the fork any less comfortable and some might appreciate the aesthetics.

The fork has a bigger offset than usual. This helps keep the front wheel away from your feet, although the effective top tube length isn't that short in absolute terms, merely for a Flat-bar bike; the front centres distance is fine. There's plenty of room for a mudguard without it catching on your Hush Puppies or sitting too close to the tyre. More offset on the fork means less trail. Steering is a little light and a slacker head angle would be an improvement.

Extra comfort also comes from the contact points, which Specialized get totally right. Beginners whose hands and sit bones haven't hardened like teak will appreciate this most, but it's a nice bonus for anyone. The Body Geometry saddle has a pressure-relieving groove that prevents nerve pinching in your perineum and, if you're wearing jeans, stops the seam sawing into your soft bits.

The BG grips are flared towards the end, like Ergon grips, for the heel of your hand to rest on. And Specialized have thrown in bar ends so you can move your hands around. The training-grade wheels are okay, and they're shod with puncture-resistant tyres: Specialized's own All Condition Armadillos in 28mm. They roll fine. Grip wasn't the best going round a greasy roundabout at speed, but that was more likely to be the light loading of the front wheel, caused by the upright posture, than the traction of the rubber. Don't bank it like a criterium bike and you'll be fine.

The V-brakes would be better with full-length arms than mini ones. You'd get more braking power and the straddle cable would sit above the underside of the fork crown instead of eating into the available tyre and mudguard space. The gear shifters are already mountain bike ones rather than Flat-bar road, and they're separate anyway so it's not a complicated or expensive upgrade to switch the brakes.

Conversely, the trekking gears are spot on. With a range from 26x32 to 48x11, you're never reaching for a gear that isn't there, and unless you live in Matlock you'll be fine even with a rear rack fitted and loaded. There isn't that huge 16-tooth jump between front chainrings like there is with a compact double, so it's easy to click up and down the gears and keep a steady cadence.

Cadel Evans (BMC) sealed Tour de France victory on Sunday after enjoying an untroubled final day on the road to Paris, while Mark Cavendish (HTC-Highroad) dominated proceedings in the finishing sprint on the Champs-Élysées to secure the green jersey.

For the third time in as many attempts, Cavendish took a comfortable win on the famous boulevard, and for the third consecutive year, Andy Schleck (Leopard Trek) stood on the second step of the podium in the shadow of the Arc de Triomphe. Familiar as those scenes were, however, the real story of the day was a rather more novel one, as Evans became the first rider from the Southern Hemisphere to win the Tour de France.

On crossing the finish line, Evans was struggling to come to terms with the magnitude of his achievement and admitted that it was difficult to estimate the impact his win would have in Australia.

"I haven't had time to consider that aspect, to be honest," Evans said. "It's been a long, long process and it will take a long time to realise what it means."

Evans finished 1:34 clear of Andy Schleck and 2:30 ahead of his older brother Fränk to finally win the Tour after years of heartache, and he was keen to pay tribute to the support of his family and his BMC squad.

"A few people always believed in me and they're the people that matter the most. We did it," Evans smiled. "It's been a real pleasure these past three weeks."

In spite of becoming the first siblings to finish on the Tour podium, there was palpable disappointment for the Schleck brothers at falling short of bringing the yellow jersey back to Luxembourg for the first time since Charly Gaul's triumph in 1958.

The stage winner Mark Cavendish was understandably in rather more ebullient mood after his fifth stage win of this Tour, and his twentieth in total, a remarkable figure for a rider who only turned 26 in May. In seeing off the challenge of Edvald Boasson Hagen (Sky) and André Greipel (Omega Pharma-Lotto), not only did the Manxman underline his status as the pre-eminent sprinter of his generation, he also secured the first green jersey of his career.

Cavendish explained that the headwind that greeted the riders coming off the Place de la Concorde meant that he started his sprint later than in previous years.

"I left it until 170 metres to go today, I knew it was going to be tough," Cavendish said. "I'm so, so happy and so proud of the guys. It's a great way to finish the Tour.

"I've been trying to get this [the green jersey] for the past few years and finally I've done it."

Cadel Evans knows how he feels.

Built for the long haul and perfected on the cobbles of the northern Classics, Synapse won Bicycling magazine's 2010 "Best Plush Bike" award and Top Velo's "Cyclosportif Bike of the Year".