Aerodynamics In Triathlon Bike

Most triathletes are aware that optimizing their aerodynamics can help them compete quicker and benefit more from their training.

Do all you can to decrease the volume of the area you are exposing and decrease the turbulence of the wind so you can expend fewer calories to fight against air resistance, which is pivotal if you desire to beat your records or competitors.

Just how important is aerodynamics? If two cyclists ride at the same power level, a bicyclist with correct posturing can decrease their time by 2-8 minutes over an 18-mile trip, and up to a full hour when doing an Ironman when compared to a person with an awkward bike fit.

It has been suggested that aerodynamics is relevant even when travelling at slow speeds like 12-14 mph, and the impact of aerodynamics becomes more significant as the speed increases.

Roughly 85% of energy expenditure while cycling is devoted to getting through air resistance, with another 10% dedicated to fighting rolling resistance, and the remaining 5% spent fighting the friction on the drivetrain.

Fortunately, when it comes to optimizing aerodynamics, we have access to speed at no cost, which we will go over in detail here.

Fit Fundamentals

It is essential to improve your posture on the bike to reduce up to 85% of aerodynamic drag created by the cyclist. The key equation to remember is:

Speed is attained when comfort, power, and aerodynamic factors come together and drag and friction are minimized.

Saddle Position

New riders typically err by assuming the bike seat is like a chair and sitting on it incorrectly. This setup is neither aerodynamically favourable nor comfortable for long periods.

To be more comfortable and streamlined, try to tilt your pelvis toward the front as much as it’s comfortable for you. Learning a new riding posture may initially seem off-putting, but it is actually extremely beneficial in terms of speed and comfort. Furthermore, it can reduce stress on your back when you are in an aerodynamic position.

You’ll likely need to sample different saddles until you locate the one that suits you best. Your chamois can also make a difference.

If chafing, saddle sores, and numbness are typical issues for you, you should not go with a thick chamois as it can bunch up and make matters worse.

A super light chamois, such as in triathlon shorts, that can dry quickly may help you stay in an aerodynamic position for a long period in a comfortable manner.

Back Types

John Cobb has been very popular in the field of fitting for a large period. He is often referred to as “Mr The Wind Tunnel is renowned for his association with Lance Armstrong at the beginning of his Tour de France career, as well as for being linked with many elite triathletes.

John starts off with measuring physiological signs and the points where muscles activate to evaluate the strength of body positioning and then moves forward from there. He separates cyclists into two distinct postures (“A Back” and “B Back” riders) to aid in making determinations.

A quarter of riders are categorized as “A Back” riders. In general, people in this group tend to have more physical prowess and the ability to bend in their stomachs and lower spinal region.

Squeezing the A Back’s hips or stomach isn’t a major problem, as they normally have the flexibility and strength to manage in this position. They can ride bicycles with a seat angle of around 74-78 degrees, and feel comfortable while sitting on the front of the saddle.

Riders with a “B Back” position are not as flexible in their lower back region but can still get a similar aerodynamic experience to those with an “A Back” positioning. These riders usually have arms further apart, with most of the stretching happening on their shoulders.

The latissimus dorsi needs to be as horizontal to the shoulder joint as it can be to aid in pulling the air over the hips.

John Cobb states that a critical action for “B Back” riders to do to further enhance their aerodynamics is to concentrate on their pelvic rotation–the further forwards you can swivel your hips, the straighter your back will be.

In the interim, cyclists on “B Back” bikes can use a frame with a steep seat angle (75-82 degrees) or turn the seat post around to increase the angle at their hips, improving the power between their thighs and upper body.

Shorter Cranks

It is not necessary to use longer levers to generate power, despite what some riders may believe. Using shorter cranks won’t affect the amount of power you can generate, plus it can make it easier to pedal at the top of the motion while giving you more room to breathe.

If your hip muscles are so tense at the upper part of your pedalling motion that it is hard for you to take in air, possibly using shorter cranks could be the answer.

Finding A Sustainable Position

This leads us to a crucial aspect of aerodynamics: finding a posture that you can maintain for the entirety of your race.

Even if you can achieve the best aerodynamic position available, if you can’t sustain it throughout the event, it will lead to wasted time since you’ll have to frequently get out of position to stretch and adjust.

According to Matt Steinmetz of 51 Speed Shop, being comfortable means you can stay in the same spot for the entirety of the event. If you are feeling uncomfortable, it doesn’t matter what else you are doing; you won’t be able to stay in your current spot.

It is important to remember that the posture used for time trialling/triathlons is not a natural pose for the body.

With persistence in your flexibility and practice, you may eventually be able to maintain a more streamlined position; however, it is not advantageous to push yourself into a position that causes discomfort as it will stunt your speed.

Safety and Stability

According to Barry Anderson from Cyclologic, reducing the front end of your bicycle or removing all the spacers is not the only component of superior aerodynamics when riding a bicycle.

The first rule is that the cyclist must be firmly situated on the seat and pedals. You want to be able to generate power from both sides of the cycle.

A stable position is also a safe one. Take into account that your riding position and choice of setup may have an effect on your bicycle’s manoeuvrability – for illustration, having a big gap between the stem and aero bars can make the cyclist have difficulty steering.

You should also make sure you can view ahead of you while you are biking–it may be acceptable to stay focused on the path ahead while competing in a time trial event, however, when you are participating in a triathlon or cycling outdoors, you must be aware of vehicles and other cyclists.


Another key factor is the ability to breathe. When a cyclist is hunched over in a position that reduces air resistance, their diaphragm can become constricted, which in turn can lead to an elevated heart rate and higher breathing rates, causing tension throughout the body.

Keep in mind that you will have to keep on sprinting after you are done cycling, so make sure you can breathe comfortably while still enjoying the aerodynamic advantages.


You’ve still got to pedal the bike, but if you pick the right gear you’ll save a lot of time, energy and power when you’re racing.

Talking about sports like cycling and triathlon, you will get the most from your equipment if you know where to invest. As these activities are usually quite costly, knowing where to put your money will save costs in the long run.


While adding aerodynamic wheels may increase weight, this is typically counterbalanced by the aerodynamic benefits gained. The typical front wheel uses 30-40 watts when travelling at 20 miles per hour, although a decent aerodynamic three or four-spoke model will utilize 15-25 watts, and a full disk wheel will only take 5-10 watts.

Essentially, you can lower energy consumption by 10% if you modify your wheels. It’s not straightforward to just pick a disk for the front and back.

When it comes to outdoor racing, a front disc wheel isn’t often used because it can be very unstable in strong winds. This is different from track racing, which is sheltered from crosswinds.

Generally, most circumstances are better suited to having at least one back disc wheel. The choices made will depend on the weather and track circumstances on the day of the race, and this is when programs such as Best Bike Split can come in handy to assist the cyclist in making the most ideal decision.

What does it mean to be aero?

The basics of bicycle fitting will stay the same – having your elbows rest on arm cups and arms extended on the extensions – however, each bike fit is unique.

It is strongly suggested that if you are thinking of changing from a standard riding position (for example, on a road bike) to incorporating an aerodynamic position, you obtain the advice of a bike fitter before doing so.

Missy Erickson is the proprietor of the Ero Sports Pennsylvania business and a holder of a World Cup medal. She has fitted numerous cyclists, both those who were curious to make their bike more aerodynamic, by either connecting clip-on aero bars to their road bike or purchasing a triathlon bike that already has aero extensions.

Erickson has found that the ideal combination of comfort and efficiency can be achieved by being aerodynamic.

Erickson suggests that the most effective posture while emanating aerodynamic forces is the one which produces maximum efficiency. To be able to perform at your best on race day, it is important to find a balance between comfort and efficiency.

Erickson pointed out that it is frequent for sportspeople to copy the stances of other sportspeople they watch, however, this is a perfect formula for disaster.

Importance of Aero Position

If you’re wanting to step up your performance during a triathlon, you can acquire more speed without spending money by finding an aerodynamically better bike fit.

In certain experiments, cyclists were able to reduce their usage of energy by 70 watts within 10 miles when transitioning from a standard road bicycle posture to a more aerodynamic posture when on a triathlon bike.

Seventy watts of additional power equates to multiple minutes saved in terms of speed. Every cyclist’s specific power and speed gains will be varied when they switch from a road bike to a tri bike, although research shows that with a successful bike-fitting, riding aerodynamically will lead to faster speeds with less energy expended.

Lexy Troup, who is originally from Fort Collins, Colorado, was a collegiate swimmer before competing in triathlon for fitness and to meet people following her years of intense swim training.

After finishing her first sprint triathlon, Troup understood that she wanted to confront greater lengths in the competition and that her normal street bicycle would not be sufficient to spend hours on the seat.

Troup states that his trainer for the triathlon motivated him to purchase a triathlon bicycle to help him prepare for his initial half-ironman. He informed me that utilizing it will spare me effort and time over long distances. At first, I was somewhat doubtful – I was used to putting a lot of effort into reducing my personal record by even half a second as a swimmer, but it turned out my investment in a triathlon bicycle was worth it.

Troup procured her initial tricycle a couple of months before her 70.3 race and got a fit to go with it. At first, Troup thought the aero position looked very painful, however, after consulting with some bike experts and getting fit, she found out that it didn’t have to be so uncomfortable.

How low should you go in an aero position?

Going in a more aero position will reduce the hip flexibility in cycling, as well as needing to tilt the head up to observe and having to shift more of your weight forward on the bike.

This could result in physical issues including cramping and decreased manoeuvrability due to excess weight being placed on the handlebars.

Can a person achieve a very relaxed and aerodynamic position? Absolutely.

Experienced racers whose bike fit has slowly adapted to their range of motion and objectives, they may be able to get extra speed with a more aggressive posture, but it is generally not the advised approach for those who are just beginning with a triathlon bike.

In the aerodynamic posture, an advantage is that the puff of air and the flow of the wind will move more accurately over you, as opposed to needing to get around you as with the typical standing demeanour.

Benefits of this posture, which looks strange, including being better able to endure the physical requirements of extensive events compared to when the rider is in the usual posture.

A customized cycling fitting is necessary here. Without having an expert assess your bike fit, attempting to adopt an aero position while cycling could result in extreme discomfort and even injury.

Getting comfortable in the aero position

No matter how you look at it, the situation with Aero is always uncomfortable. It is not normal for humans to be in a hunched-over position while riding a bicycle.

Initially, you could experience an inclination of leaning too far forward or almost as if you are lying on top of the bike with a sense of being extended out. These initial observations of your cycling posture may be common but you should still discuss them with your bike fitter during the beginning of the bike fitting process.

Once your positioning on the bike is adjusted properly, you should feel comfortable in an aerodynamic position. You should not overwork your core by keeping your abdominal muscles tense for too long while biking, and you should not grip the aero bars with excessive force.

You should be firmly planted in the centre or close to the front of your saddle, with a light but firm hold of the aero bars.

The initial few jaunts with your new aerodynamic posture may mean you experience some discomfort in your muscles: you may find your neck, shoulders, and bum to be quite rigid following a lengthy ride. As long as the pain is not too bad or lingers for several days after the ride, this is to be expected.

It is essential that someone who is experienced with bike fitting address low back, hip, knee, or groin pain immediately, as these can be warning signs that something is wrong with the bike and needs to be adjusted, e.g. the saddle height or type of saddle. Ignoring these indications can lead to continuing pain or sores in the saddle area.


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