cycling performance

Aerodynamics and bike fit for speed

Some practical wisdom on endurance sports nutrition from the book is "The woman Triathlete", reprinted with permission by Human Kinetics.

"How fast you finish the cycling portion of a race depends on the power you’re able to produce during the ride. Ultimately, power output depends on just two variables: force and speed. Very simply, it depends on how hard you push and how fast you pedal. The three forces you need to overcome to move forward are air resistance, rolling resistance, and, on climbs, gravity. Because gravity and rolling resistance depend on weight, most cyclists try to minimize weight. This is most easily achieved by using a lighter bike and componentry, but these come at a high cost. Rolling resistance also depends on the road surface, as well as the make, thickness, and pressure of your tires. The biggest resistive force, however, is air resistance, which is dependent on your speed and frontal surface area. At 20 miles per hour on a flat road (gravity is zero), rolling resistance makes up less than 25 percent of the total resistance, while air resistance makes up more than 75 percent. The most effective way to reduce air resistance is to draft behind (or even next to) another rider. For a triathlete without the option to draft (drafting is not permitted in most amateur triathlon racing), reducing frontal area has the greatest effect on performance. Aerodynamic equipment--such as bike frames with tear-shaped tubes, deep-dish wheels and discs, narrow water bottles, tight skin suits, and streamlined helmets--can reduce some of the frontal area. However, a rider’s body is by far the biggest obstacle. Bike fit for a triathlete is therefore optimized with biomechanical fit and aerodynamic positioning; many triathletes even choose to ride a less comfortable setup in favor of better aerodynamics. Keep in mind, though, that a comfortable setup that incorporates aerodynamics will usually result in increased power output. Because road cyclists are allowed to draft, they tend to place greater importance on biomechanical fit, comfort, and handling of the bike than triathletes do, but triathletes would be well served in finding a comfortable setup.


It is relatively easy to adjust a traditional bike fit to a more aerodynamic fit. The most cost-effective investment is a set of aerobars. Better yet, using an ergo-stem along with your aerobars will allow you to more completely adjust the position of your handlebars. A second seat post and saddle combination will allow you to quickly move back and forth between a road position and a time trial position with just one bike frame. Because a traditional road bike fit often results in better (i.e., easier) handling of the bike, it is useful to be able to switch back and forth between setups. You can convert your bike to match your workout--aerodynamic position for solo efforts and time trials or a traditional bike fit for group rides and hilly routes. Before you adjust your bike fit to a more aerodynamic position, measure (and mark with tape) how your bike is set up. It is always a good idea to have the option of going back to a position that already works for you. Once you have the necessary measurements, move your saddle forward one or two centimeters. Because this reduces the distance from your saddle to the bottom bracket, you may also need to move the saddle up (usually about half the distance that you moved it forward). Now check your reach by leaning forward into the aerobars. The front of your shoulders should be aligned vertically with the back of your elbows. This position allows you to rely on the skeletal rather than muscular support of your upper arms for the weight of the upper body. Your comfort and flexibility should determine the height of the handlebars relative to the saddle. For example, if your hamstrings feel tight, your handlebars need to be moved higher. Most likely, your cleat position and your saddle tilt can remain in the same position as they were in before.

No matter how aerodynamic you want to be, injury prevention and comfort should be your main concerns with regard to fit. Your knee rotates through many cycles on a ride--in just one hour of racing at 90 revolutions per minute, you are completing 5,400 rotations per leg! If your bike is not properly fit to your biomechanics, you will be at high risk for injury. Also, if you are uncomfortable on the bike, you may become distracted by repetitive twinges instead of being able to focus on your effort. Because a proper bike fit is critical, you should be fit at a reputable triathlon or cycling shop, by a certified fit specialist, or by a coach or physical therapist who has experience in bike fit. A proper bike fit should always include setting up your cleats (on the bottom of your shoes) in the proper position: If your knee is restricted to the wrong range through each pedal cycle, you’re almost guaranteed injury. Athletes looking to be very competitive in triathlon should consider being fit by a professional fit specialist who will take into account every aspect of their biomechanics when adjusting their position. Look for someone who specializes in triathlon-specific fitting, and expect to pay $50 to $100 for the service (and anywhere from $200 to $1,000 for services that include power output measurement or wind tunnel testing).

Even with a good bike fit, you may find that you are uncomfortable on your saddle at times. If you experience this, consider the following:

  • Never wear anything under your cycling shorts. The shorts are designed so that there are no seams in sensitive areas. Wearing undergarments adds those seams back between you and your saddle. Also, make sure you buy women’s shorts to ensure a proper fit.
  • Wash your shorts after each ride to avoid infections.
  • Use a chamois cream or ointment to prevent saddle sores and chafing. Apply it to both your body and the shorts for maximum protection.
  • Use a women-specific saddle. They are designed to support the wider sit bones of a woman’s body and provide increased comfort."

Top 3 bike selection steps for triathletes

Having the right bike for you and having it dialed in can make a lot of difference.  It will make the ride performance better all around.  It can also help prevent injuries associated with cycling and cycling position.  This excellent excerpt from Triathlon Workout Planner by John Mora reprinted with permission from Human Kinetics.
 

Selecting a bike

"If you’ve only recently been bitten by the triathlon bug, the very first, most obvious symptom is an inexplicable need to visit the nearest bicycle shop. Once you’re there, your symptoms might progress toward writing out a check for a thousand bucks, or worse, taking out the plastic. Hold on there. You might not need to shell out four figures at this point.

If you currently own a bicycle and just want to finish your first triathlon, you might be able to get by with what you have until you’re sure you’ll be a lifelong multisport maniac. It’s not uncommon for beginners to use a beat-up old road bike or a fat-tire mountain bike for their first event, and there’s nothing wrong with that. However, if you don’t have a bicycle (or can’t borrow one), then you have no alternative but to look into buying a triathlon bicycle. Also, if you’ve done a few triathlons and are looking for some advice on making your first serious multisport bicycle purchase, the following sections provide some guidance for you.

Tri-Bikes, Step by Step

Making your entry into the complicated world of cycling equipment can be expensive and intimidating. Somewhere among the fancy designs, shiny components, and black rubber is what you need. Without some basic knowledge, a good understanding of your current needs, and a clear vision of what lurks on your triathlon horizon, there’s a strong chance that you’ll purchase the wrong bicycle.

Fear not. Here’s a step-by-step guide to making that first big multisport purchase, with advice from triathlon bicycle dealers, manufacturers, and coaches. Add to that some tales of woe from professionals who can tell you (through their experience) what not to do when you’re making that big purchase, and you have no reason to panic.

Step 1: Set a Budget

Walking into a bicycle shop with no plan can mean walking away with no money. Although most bike dealers will not deliberately take advantage of an eager first-time buyer, by setting a budget you are taking the first step toward controlling a situation that might seem uncontrollable.

A cautionary word about overemphasizing equipment is warranted. “Your best bet is buying a reasonably priced, entry-level bike with a clip-on aero bar,” says cycling coach Bob Langan. “It all comes to this: It’s not the seconds equipment will save you; it’s the minutes a good aerodynamic position and proper training will.”

How much will you spend on your first triathlon bike? Generally speaking, prices for entry-level racing bikes range from $900 to $1,400. Of course, the sky’s the limit on how much you can spend (if your bank account can handle it), but spending more than $1,400 is risky for two reasons:

1. You might not know what you need.

2. You might think you know what you need, but you might be wrong.

Does that mean you should go the other way and get the cheapest two-wheeler you see on the dealer floor? No. Although the frugal side of you might want to buy the cheapest Wal-Mart special you can find, you’ll likely find it to be less than what you need. Better to buy the most bike you can afford and be able to train and race with comfortably, than have to start all over a few months down the road.

Step 2: Don’t Forget Accessories

One common mistake is excluding accessories from the budget. Earmark $300 to $500 for accessories, more if you intend to purchase optional equipment such as an aerodynamic disk, tri-spoke, or deep-rim wheel. Some of the more basic bicycle accessories include the following:

  • Frame pump
  • Patch kit
  • Spare tubes
  • Helmet
  • Clothing (shorts, jerseys, jacket)
  • Gloves
  • Cycling shoes (optional)
  • Clipless pedals (optional)
  • Aerobars (optional, but highly recommended)
  • Computer (optional)
  • Sunglasses (optional)

As you can imagine, your $900 bicycle purchase can run well into four figures with the addition of these or other accessories. Is all this stuff really necessary? Most of it is. You can’t race without a helmet, and you need the additional comfort and safety that cycling shorts, jerseys, gloves, and the other necessities afford you.

If you intend to transport your bicycle in your car, a roof-mounted bicycle rack can run you well over $500. A less expensive alternative is a trunk-mounted rack. Still cheaper is taking the wheels off your bike and throwing it in the back seat or trunk.

In recent years, many bicycle manufacturers have included clipless pedals, contraptions that attach your shoes to the bike for an efficient, more comfortable pedal stroke, as basic equipment on entry-level road bike models. This addition will save you close to $150 that you might have earmarked for this accessory. (If the bicycle you’re interested in doesn’t include clipless pedals, it’s time to start negotiating with your dealer.) Though many people fear being attached to a bicycle with clipless pedals, you can get out of the pedals at any time simply by extending your heel outward.

Cycling shoes are designed for use with clipless pedals. Cycling shoes are stiff and transfer energy more directly to the bicycle than do rubber pedals or toe straps. Cycling shoes vary widely in price, from $100 on the low end to more than $200.

Aerobars help you slice through the wind. Better aerodynamics with aerobars increases your speed and helps you save energy for the run. As you train for longer distances, this accessory will definitely fall out of the “optional” category and into the “mandatory” list.

Speed Demon Fact

If you recall, Greg Lemond’s historic victory in the 1989 Tour de France came as a direct result of the performance advantage of his triathlon aerobars. Wind tunnel testing has shown an estimated average time savings of five minutes during an Olympic-distance bike leg (40K) when a cyclist maintains an aerodynamic position on aerobars. Other studies have shown that cyclists in a proper aerodynamic position are more relaxed and experience decreased heart rates.

Step 3: Understand the Choices and Know What You Need

Purchase a good racing bicycle that is versatile and durable. Buying an entry-level racing bike that is upgradable can save you time and money in the long term. For example, pioneering duathlete Ken Souza’s first duathlon bicycle was a Nishiki International he bought in 1982 for a scant $175. Though the bicycle served its initial purpose, it was a touring model (a bicycle designed primarily for casual riding) that Souza quickly outgrew. Yet the pioneering athlete who put duathlons on the map continued to pour money into a pocket full of holes. “It was ironic. I was spending all this money trying to upgrade, trying to save a few dollars by not buying a racing bike. I could have bought a real racing bike sooner if I hadn’t tried so hard to upgrade a bike that wasn’t worth it.” So Souza’s experience makes an important distinction—find a good upgradeable bicycle, but just be sure it’s something that’s worth upgrading over a reasonable period of time, You may very well outgrow an entry-level bicycle, but try and find something that will last you for as long as possible.

Souza’s solution to his novice woes was one that you might want to consider if the opportunity arises: “I bought a used racing bike—a Vitus carbon fiber—from ex-pro Mark Montgomery. I think that’s one of the smartest things a beginner can do. You’ll get top-of-the-line gear, you can get a great deal, and it’s usually not beat up.”

Cycling - Trends in Tour Races

In this excerpt, we learn about "Trends in Tour Races", reprinted with permission of Human Kinetics.

"Since the beginning of the 20th century, three-week tour races have been extremely demanding. Compared to the old days, the current trend is toward shorter, more intense daily stages. In the years to come, it is expected that the average amount of time a cyclist spends in zone 3 per stage will be more than 30 min.

Physiological Demands of the Different Phases of Tour Races
In general, three-week tour races have three main competition requirements: flat and long parcours (usually ridden at high speeds inside a large group of riders), individual High Tech Cycling - Science of riding fastertime trials (40 to 60 km over level terrain), and uphill cycling (high mountain passes).

Every tour race includes seven or more flat stages of about 200 km, lasting four to five

Back strengthening can prevent cycling injuries

Strengthening can be a part of your routine and many might say say it should be.  Triathlon, multi-sport, uses many of the muscles in your body during a race or brick work-out.

I like researching question like, "How can a muscle be strong and flexible?"  "Is strength just the capacity for movement in relation to distance and time?"  If so, strength training will always play a part of my training.

Here's an excerpt titled, "Developed back muscles prevent cycling injuries", from Cycling Anatomy, reprinted here by permission of Human Kenetics. One of the best things about this book is each exercise is explained in detail including which muscles are used, and how exercising that muscle groups is useful in cycling.

"The importance of a strong and fit back cannot be overemphasized. The back and spine provide the foundation for almost every activity performed, and cycling is no exception. Unfortunately, back problems are a frequent complaint of cyclists. Because of the bent-over position on a bike, back muscles are constantly engaged. This stress can wreak havoc on the body if it isn’t conditioned and trained to withstand the ongoing effort. In addition to withstanding the strain of the cyclists’ position, the back must also provide a solid base that enables a cyclist to generate power during their pedal stroke. Back muscles stabilize the spine and pelvis, allowing the legs to generate maximal power.

The best strategy for a healthy back is to proactively condition the body to avoid any problems before they arise.  Take time to build strength in the back—this will pay dividends in the long run.



Stability Ball Extension

Execution

  1. Lie with the lower abdomen draped over a stability ball.
  2. Keeping one foot on the floor, arch the back while raising and extending the arm and opposite leg. The elbow and knee should be straight (extended).
  3. Slowly lower the arm and leg. Curl the body around the stability ball.
  4. Repeat the exercise using your other arm and leg.




Muscles Involved
Primary: Erector spinae
Secondary: Splenius capitis, gluteus maximus, deltoid

Cycling Focus

The erector spinae muscles must withstand enduring workloads when riding a bike. For the majority of rides, these muscles will maintain a forward leaning posture. If the back becomes sore or fatigued, the erector spinae muscles are usually the culprit. The stability ball extension is particularly effective because it provides full range of motion at maximal extension. This will counter the hours spent with the back arched forward on the bike. Added weights are not needed to make this workout effective. Remember that stretching and moving muscles through their complete range of motion will help get the most out of muscle fibers."

The Science of Cycling Position

Here's another excellent excerpt reprinted with permission from Human Kinetics of High-Performance Cycling by Asker Jeukendrup

cycling performance"Throughout this chapter, we have used a set of reference values for aerodynamic drag area. Although these values represent good approximations to the drag area of a 70-kilogram (154-pound) rider in each position, those values are not fixed. Rather, a cyclist can influence his drag area in several ways. Riding with knees close to the centerline of the bicycle frame can reduce drag area by approximately 8 percent compared with riding with knees wide apart. This knee position will affect drag similarly whether the rider uses conventional racing handlebars or aerobars.

For riding with standard handlebars, arm position, including elbow bend and forearm alignment, can even more dramatically influence drag area. Bending the elbows allows the rider to lower his torso and thus reduce frontal area. Indeed, carefully positioned arms with the forearms horizontal and parallel to the bicycle can reduce drag area by up to 12 percent compared with widely positioned arms or straightened elbows. A wide-elbow position may result from poor technique, but it also may be due to poor bike fit and thus may not be within the control of the rider. Specifically, if the saddle-to-handlebar distance is too short, the rider may be forced to widen the arms so that they do not contact the legs. Consequently, drag area may be substantially increased because of a poorly fitted frame-stem-handlebar combination.

Optimal Time-Trial Position
Riders often ask, "How do I optimize my time-trial position?" The simple answer is, "Go to a wind tunnel and have your aerodynamic drag measured in various positions." But, of course, not every cyclist has the opportunity to take part in wind-tunnel optimization.

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