5 Factors for Selecting a Bike for Your Next Triathlon

5 Factors for Selecting a Bike for Your Next Triathlon
A triathlon specific bike, or tri-bike, puts the rider in an aerodynamic position

If you have visited a bike shop recently, you will find a mind-boggling number of styles of bikes.  The many options are aimed at different budgets and designed for different types of riders, terrains, and activities.

Factors in Choosing a Bike

Selecting the bike that you will you use for your triathlons is a very individual decision. The following five factors can be used in making this selection.

  • Cost
  • Comfort
  • Construction
  • Course
  • Commitment

A new entry onto the bike scene has been the so-called ‘Fat bike’ designed for riding in soft surfaces such as sand and snow. Click here to see fat bikes in action at the USAT National Winter Triathlon Championship.  At an open house of my favorite bike shop yesterday, I was told that nearly everyone working in the store now rides a fat bike year round.


Why Ride in the Aero Position?

Compared to other activities involving bike riding, the conventional (swim/bike/run) triathlon involves the triathlete completing the bike leg, getting off the bike, taking off their helmet, putting on running shoes, and setting off for a run of at least several miles/kilometers. The amount of work done by the running muscles, primarily the quadriceps and hamstrings, during the bike leg and the time that it takes for the running muscles to adjust to running is key to the run speed and one’s overall performance (time) in the race.

For this reason, the triathlon specific bike, or tri-bike, is designed to be ridden in an aerodynamic (also known as “aero”) position (see picture below).  The aero position is one which the rider is in a forward position with forearms resting on pads mounted to the handlebars.  Riding in the aero position minimizes the work required of the main running muscles during the bike leg.

Trek Speed Concept 7.5

The triathlon-specific bike is meant to place the rider in a forward, aerodynamic (aka “aero”) position to reduce the work required of the muscles that will be called upon in the run leg.


Despite this, one will see many different types of bikes in a triathlon, at least those in which I participate.  After all, triathlon is meant to be about remaining active and fit, and not necessarily, about setting race records.

So, with that background, let’s review the factors in selecting the bike.



The good news is that you probably have access to a bike for your next triathlon. If you do not already have a bike, you may borrow one from a friend or family member.  My first triathlon involved using an existing, hybrid bike. The experience is told in the Our Stories (link) section of the Senior Triathletes website.

Giant hybrid bicycle

A hybrid bike is a good alternative to a triathlon specific bike or road bike for triathlon.

If you decide that you want to compete seriously to win a race or your age group, then you will want a triathlon bike or at least a well-outfitted road bike. In that case, the bike will easily become the most expensive piece of race gear.  Price tags for triathlon specific bikes easily reach well into four figures. In fact, it is not difficult to find bikes that cost five figures.



In my experience, riding a triathlon bike is not nearly as comfortable as riding a hybrid bike. The same can be said for the road bike compared to the hybrid.

I have changed the seat on my triathlon bike from the one with which it was originally fitted. This has made the ride more comfortable (less numbness in the seated area).   However, it is still not as comfortable as the seat on my hybrid bike. I often joke that riding the hybrid is like riding while sitting on the couch.

Getting comfortable riding in the aero position can be a challenge. For a triathlon bike, riding in the aero position is, for practical purposes, required since the shift levers are at the far ends of the aero bars.  I will not ride my triathlon bike on winding trails and, especially on trails with pedestrian traffic.

On the other hand, the triathlon bike is much faster than a hybrid bike and saves the legs for running.



As summarized in the table below, factors such as race/ride distance, rider weight, and frequency of which the bike is ridden can influence the optimum material of construction.

Material Strengths Weaknesses
Aluminum (or


Light and stiff – ideal for shorter distances and hill climbing Lighter weight riders and anyone with aches and pains, such as a sore back, will feel roughness in the road.
Steel Strong and elastic (flexible) – good shock absorbency, ideal for long rides. Relatively heavy, though in the context of the weight of the rider plus bike, this is a minor weakness.
Carbon fiber Best shock absorbency – good for long distance rides and riders with sore backs. Flexibility can result in loss of power being transferred to the bike, which will be a more important factor for hilly rides.
Titanium Good shock absorbency for rough roads and stiffness for efficient transfer of power to the bike. Expensive
  1. This is the spelling most non-American English speakers will recognize.

The source of comments about strengths and weaknesses of the materials is http://www.active.com/triathlon/articles/7-steps-to-find-your-tri-specific-bike.

The construction of the wheels and drivetrain and brake components can also affect the performance of the bike through their weight and reliability.



The previous section highlighted that the smoothness (or roughness) of the race course affects the optimum material. Taking this a step further, if you compete in races involving off-road bike courses, you will need a mountain bike or fat bike.

Putting this aside, the main variable that will likely be considered in selecting a bike for triathlon is the size of hills included in the course.

The ideal bike for hilly courses is low weight and has gearing ratios consistent with the grade of hills. Without the correct gear ratios, one can quickly run out of gas when climbing steep hills. (In my experience, this also occurs even sooner at a higher elevation.)



Buying a triathlon bike represents a commitment to the sport. When I was shopping for a new bike after my first triathlon and I had decided to get ‘something’ different that would be faster, I spoke with a person from my local bike shop. His advice – which I am convinced is correct – is that if you are looking for a general purpose bike (triathlon plus rides with the family), get a road bike. If however, you want to get the best performance in the bike leg of a triathlon, get a triathlon bike.


Make sure it fits

Getting a bike that fits properly is critical. Having an expensive triathlon bike for which the seat, aerobar rests, or other main components are not adjusted for YOUR specific body proportions will be frustrating.   Riding a bike that does not properly fit the rider can even be painful.

As I have gained experience and flexibility, I have also had the bike fit checked and adjusted.

Send any questions or comments to seniortriathletes@gmail.com.


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