How to Fit a Triathlon or Time Trial Bike Part 1: Overview

Triathlon and Time Trial Bike Fitting Part 1:  

Overview

Triathlete being fit with front view Time trial Bike triathlonThis article focuses on triathlon bike (TB) and time trial (TT) bike fitting.  It is not intended to be a resource for bike sizing. Often these two descriptions become intertwined. However, anyone with interest in bike fitting or sizing should understand the differences. With that said, fitting a time trial bike works best when you start with the right size bicycle frame.  At a minimum, a frame should be close enough to your correct size.

The position on the time trial bike we will discuss most will be the aero position–forearms sitting on the armrest with hands at the end of the aero bars/extensions.  This term is referred to as “in the aero bars.” This does not render fit on the base bar or cow horn section of the bars unnecessary.  On the contrary, consideration should focus here because it is the connection for starts, climbing, cornering, and where most brake levers are found. We want to help guide you to a position that you will ride almost all of the time in the aero bars. If you are not able to ride in this position comfortably, we suggest a change to the bike fit.

Time Trial Bike Contact Points Triathlon

Illustration 1 – Tri-Bike with the “target” connection points highlighted.

Triathlon or time trial vs. road bike and considerations

One thing we will not focus on in this article is whether you should be riding a triathlon bike vs. a road bike. For many, a road bike may better serve you and there is nothing wrong with riding a road bike in a triathlon.  When necessary, we will specify TB (triathlon bike) or TT (time trial bike) for distinct or modality specific descriptions/reasons.  Most of the time we will use “TB.”  Like all cyclists, athletes who participate in triathlons, duathlons, and time trials desire comfort while riding. However, unlike many road cyclists, the triathletes and time-trialists are rarely seen sitting up and relaxing.  The geometry, and thus positioning, on a time trial bike is often quite different from a road bike.

At BikeFit, we’ve developed our bike fitting curriculum to address a duathlete’s and triathlete’s specific needs. We do incorporate some of the protocols, especially with regards to hip angle, developed by Dan Empfield at SlowTwitch/F.I.S.T.  This is, of course, in addition to what we perform during a typical fit (foot/pedal interface, seat height, stance width, front view, side view, etc.).

The history of “aero”

During the 1984 Olympics and around the Olympic Training Center, many people started to notice “funny bikes,:  This was, of course, prior to the advent of “aero bars.”  Race Across American (RAAM) then showed perhaps the first version of an “aero bar.” The RAAM guys kick-started this aero bar craze, not the triathletes as many believe.  Several morphologies occurred as the triathletes attempted aero positioning. Shortly thereafter, a Boone Lennon built a set of “aero” bars for a Tour de France racer. This publicity increased the “aero bar’s” positive reception by ALL cyclists, not just the crazy long distance guys and the early triathletes. Then John Cobb helped BikeFit founder, Paul Swift, compose what may have been the first published bike fitting manual for time trial bikes and triathlon bikes in the 1990s: “The Bicycle Fitting System,” co-authored with Vint Schoenfeldt, PT.

SlowTwitch

Today, Paul Swift now also teaches at SlowTwitch, a fabulous bike fit education program run by Dan Empfield.  He is a man who has taken the side view and put it into a much easier to digest format. Dan invested more time into time trial bike and tri bike fitting than anyone on the planet. It is important to note, Dan focuses on the side view perspective but also does a great job with helping fitters generate the best size frame (bike sizing) for their clients. Together SlowTwitch and BikeFit offer the most comprehensive triathlon bike fit in the world. Bike fitting that considers only the side view is like building a house and setting it on the ground without regard to the foundation.  Fitting only the feet is like building the foundation but stopping before putting up the walls and roof.

Time Trial Bike Triathlon

The illustration above is an early version of a time trial position. This is also fairly indicative of triathlon bikes at the time that focused on the aero position.  This photo shows Chris Kostman of Adventure Corps- www.adventurecorps.com.  Chris is the promoter of the Furnace Creek 508 and an excellent BikeFit Pro. He certainly does not fit people like this today.

The differences between early time trial/triathlon bike fits and today

What are some of the differences with Chris’s fit and a triathlon or time trial bike fit today? Fittings at this point occurred before we started with the foot-pedal interface.  Chris would point out he was at the forefront of setting the cleat further back on the shoe than most prescribed. We would argue he did it before shoes were ready for that change. With the advances in cycling shoe technology, indeed cleat position changed (foot-pedal interface information).

Two major things stand out when we look at Chris: hip angle and shoulder angle. The saddle is further back than most tri bike fits today. This results in a more acute hip angle which is exacerbated by the extra-long reach to the bar.  Notice the shoulder angle; this is WELL beyond the typical 90 degrees or so we like today. Lucky for most of you, this position disappeared years ago. People ahead of you suffered so that you can achieve comfort and efficiency. A good time trial bike fit should be comfortable for the duration of your bike ride or race. You will also generate more power and increase efficiency with a quality, comfortable bike fit.

Tri(triathlon) or time trial bike position vs. road position? 

From Dan Empfield www.Slowtwitch.com   “The forward position places the rider over the cranks further and puts him/her in an aerodynamically sleek position. The position also saves key muscles for running. Road bike seat tube geometry is geared toward making efficient use of all leg muscles, especially the hamstrings, which is an important muscle to save for the run. Tri-geometry makes more use of the quads to generate power.”

We do believe most everyone agrees with Dan’s first statement–this forward position “places the rider…in an aerodynamically sleek position.”  It is Dan’s second statement that conjures disagreement among professionals.  Some studies indicated little to no noticeable change in physiological measures between a shallow seat tube angle and a steep seat tube angle.  Ben Reuter and David Pascoe completed this study and published it in 2006 ‘Medicine & Science in Sports and Exercise.’  Referring back to Dan’s statement, is that the same as saying “key muscles?” You can decide. We think most professionals agree with the use of the forward (aero) position.  However, all are not in agreement as to its exact benefits.

Position and comfort in triathlons

Before we get to cycling part of your triathlon (the third event), a good tri bike position should also be comfortable for someone just getting out of the water and onto the bike–this is rarely discussed. The majority focuses on transitioning to the run. While this factor is crucial, the run is far away from when you get on the bike and commence the highest speed section of your race. Let’s endeavor to place the athlete in the most comfortably aerodynamic position.  In the end, what is the point of improved aerodynamics if you are unable to generate an ounce of power?  We suggest when getting a triathlon bike fit, swim as close as possible or just prior to your bike fit. A few places on the planet will set this up for you. Ask if this is an interest, but places like this are few and far between.

The tri position tends to be more static than a road position. In other words, the cyclist spends less time adjusting or altering their body position while riding.  So the main focus is, for the most part, pinpointing one position on the bike. Dialing in this single position actually becomes a bit easier than a road fit. Yet, people sometimes suggest a tri-fit is more difficult.

Sizing

Sizing a TB is also not as complicated as suggested by some.  However, TB sizing takes a slightly different trained eye than road bike sizing. Fitting a TB comes down to the contact points (connection points) between the cyclist and the bicycle. These NINE contact points (yes there are nine places you touch a TB): right and left pedals (1,2), the saddle (3), right and left forearms (4, 5), right and left extensions (6, 7), when in the aero position, and right and left hands (8, 9), when upright in the base bar or cow horns.

 Time Trial Bike Triathlon
Illustration 3 – Tri Bike with the “target” connection points highlighted.

Sizing on a TB, however, probably needs to be more precise than sizing on a road bike. The choices, although many, in TB accessories can be a bit more limiting in adjustability.  A proper bike fit has more to do with the saddle, handlebars, brake levers and hoods, stem and, most importantly, shoes, cleats, and pedals than the actual frame.  As long as you get the equipment within the target range, you can achieve a proper and efficient bicycle fit.

Selling bicycles is the business of a bike or tri shop, and their focus is typically on the bicycle and bicycle frame. This is not necessarily a bad thing. Sometimes bias can enter the picture and hopefully, this does not negatively influence the bike fit.  If the shop you choose to purchase your from is not well versed in fitting (or positioning), we strongly suggest you connect with someone with fitting expertise before your purchase. A good fitting bike may reduce more time in your triathlon than any other adjustment you make (proper training notwithstanding).

Fitting

Unlike the human body, bicycles are symmetrical (other than one crank sometimes being a little wider from center than the other). That means getting the connection points into the target range is only a start to the bike fit. Not only do these points need to be in the correct area, but you need to fine tune each specific connection.  Assessing and fine-tuning the location of the bike part as it meets your body is imperative.  For example at the hands, just because you may have the correct length and angled stem does not mean you have the right shape and size of base bar or elbow rest and extensions, the proper bar tilt/rotation, and/or brake levers and their location on the handlebars. Simply because you set the cleat fore/aft position does not mean its rotation, tilt, and stance width are also correct (foot adjustment).

The ultimate result between the bike and your connection to it–the bicycle basically disappears. Once you no longer notice the bike and your focus exists solely on the ride, the scenery and/or company, you achieved a proficient bike fit. Similarly, while a triathlete may not care about the scenery, their concern is speed. When a triathlete no longer notices their bike, they are experiencing a great bike fit.  Don’t fight with your bike!  Use your motor to tear up the course.  I guarantee you if your bike “disappears” during your triathlon, the transition to the run will go much more smoothly.

Getting Started with Fit (Contact Points)

As previously mentioned, the cyclist’s body contacts the bicycle at 9 points:  hands (4), forearms (2), pelvis (1), and feet (2).  The location of the feet, pelvis, forearms and hands dramatically impacts comfort and efficiency on the bicycle. Several pieces of equipment on a bicycle are adjusted to find your ideal position on your bike:

  1. Pelvis – saddle selection, height, fore/aft, tilt and sometimes cycling shorts.
  2. Hand and forearms – base bar, forearm pads, extensions, brake levers and shift levers (all connected to the stem).
  3. Feet – pedals, cleats, cycling shoes and occasionally crank arm length

Our next 2 articles provide detailed explanations on contact points.

Learn More About Triathlon and Time Trial Bike Fitting

Are interested in learning more? Please see our next Triathlon and Time Trial Bike Fitting Article: Part 2–Pelvis/Saddle Fitting.

Time Trial Bike Triathlon Bike

How to Fit a Triathlon or Time Trial/TT Bike Part 2: The Pelvis/Saddle Fitting

saddle

TT/Tri Fitting Part 2:  

The Pelvis/Saddle Fitting

Saddle Selection

Rarely do bicycle fitting articles mention saddle selection. Reality: this should be the first step before making any adjustment to the seat height, tilt, or fore/aft position. Riding with the wrong saddle can compromise your comfort and ideal cycling position dramatically.
As simple as it sounds, the best way to find the most comfortable bike seat is to sit on it. The problem lies in the fact that switching saddles is both time consuming and difficult.  Changing a saddle can take up to 15 minutes per seat which means most people select a seat by pressing a finger into it to test its firmness or softness. Another option is simply choosing a saddle based on advertisements. Some saddle manufacturers have done a nice job with their design and a fabulous job with their marketing.  Unfortunately, this still doesn’t help you procure the ideal saddle.  Fortunately, we solved this problem. At BikeFit we built a fitting tool called the SwitchIt™ that quickly and easily allows you to test as many saddles as you’d like by sitting on them:

Not all shops carry the SwitchIt so you’ll need to ask for it or find another bike shop that does. When you find a shop with a SwitchIt, try to set the position on their sizing bike or stationary bike that has the SwitchIt mounted it to a similar position as your tri bike.  Try as many saddles as you like until you find the one that fits best before you make your purchase. It may come as a surprise that the seat you currently ride is not the best saddle for you. Let your tush be the judge!

Saddle Selection Misnomer

Beware of other ways a bicycle dealer may guide you in your saddle choice. Some bike shops may have you sit on a device that takes an impression of the width of your sit bones. If this device actually works, the best information it “suggests” is how wide or narrow of a saddle you “might” like. Unfortunately we can share with you story after story where this device does not provide information for a comfortable saddle choice.
Illustrations 4 – As you can see sitting on bike is not like sitting on a box
As mentioned, the incorrect saddle can compromise your position on the bike and, of course, feel uncomfortable.
As you try to find the right saddle, keep an open mind. Some shops may start you down a saddle choice path by pointing out saddles designed for triathlon or for men or women specifically. However, some triathletes find a road saddle more comfortable and some men may find women’s specific saddles more comfortable or the other way around. Either way, please be ready and willing to try ALL kinds of saddles.

Saddle Cutouts

Are seats with a cutout good? It depends. It seems that in the past some seat manufacturers added a cutout to make up for their less-than-ideal saddle design. Many saddles did not offer the ideal support in the right area. A good-fitting saddle may not need a cutout if the support is in the ideal area for you. Where is the ideal area? It varies from person to person.  In general, for most of us (male or female) it means not too much pressure in the front or in the center of the saddle.  For some, sitting slightly off to one side may be the answer.  Bike fitter extraordinaire John Cobb often recommends positioning the nose of the saddle to one side.

Illustration 5– tip of saddle rotated to the right. To see more about John Cobb today: www.cobbcycling.com

Ultimately a cutout seat may prove the most comfortable, but don’t discount those saddles without a cutout before trying them first. You may surprise yourself as to which feels best.

Saddle Tilt

Is a level saddle the best position for you? It may be ideal for some but probably not for every triathlete. Numerous people tilt the saddle nose down thinking it will increase comfort. If you must tilt the nose down more than a few degrees, you may not have the right saddle and/or the overall bike fit is likely too far off. Too much downward tilt usually results in your pelvis sliding forward. This leads to hand, elbow, forearm, triceps and shoulder discomfort or pain. You may find yourself pushing your pelvis back from the bars several times in a ride. Some people will also feel like they are pedaling more with the tops of their quads (just above the knee).  While not as common, some saddles feel better with a slightly upward tilting nose. The best adjustment for your saddle really depends on you and on the saddle itself.  So don’t get hung up by someone saying it is “supposed to level” or “tilt” this way or that way.  Rather, adjust to what feels best.
BikeFit App Saddle Tilt Tool

The BikeFit App for iPad and iPhone saddle tilt tool.

Saddle Height

The starting point for most do-it-yourself bike fits is typically saddle height. Sit on the saddle with one leg hanging free and your pelvis level—not one hip tilted higher or lower. Your hanging leg’s heel should just scrape or touch the pedal when the pedal is at the very bottom (6 o’clock). Once you slide your foot back to bring the ball of your foot to the center of the pedal you should have a slight bend in your knee.

 
Illustration 6 – Heel Scrape

In our experience, the properly bent knee resides between 27 and 37 degrees of flexion from a straight leg. Typically, most people have greater than 30 degrees of knee bend at the bottom of the pedal stroke. The Empfield – F.I.S.T guide suggests an even lower saddle height range.  Collectively we feel that you will almost never see someone needing to be taller than our ranges. Occasionally you might rarely see someone lower. If your hips rock a little when you pedal, lower the saddle a couple millimeters and test again. Repeat as necessary until you eliminate this rocking. You may be someone that just rocks.  Don’t feel like the Lone Ranger; you are not alone. At this point, you may want to consider shorter cranks. If you are on a fit bike with adjustable cranks, shorten them and observe the changes.
While there are formulas that take into account your inseam measurement, they generally do not produce any better result than this heel scrape method.
We recommend using a Goniometer to accurately measure knee bend. Take a look at the goniometer checking knee flexion or the bend in the knee at the bottom of the stroke:


Illustrations 7a & 7b – Goniometer measurement and proper knee angle

Saddle Height Accuracy

Can saddle height be set to the exact millimeter?  Saddle height is never the same even for the same person. What do we mean by this? What happens if they wear a different pair of cycling shorts? That precise measurement is now not so precise. Does the “millimeter measurement” account for the wear and tear of a saddle that has been ridden for a long period of time? What if the rider feels tight one day, rested the next day, or they wear additional clothing to accommodate for cold weather? The list is nearly endless. Bottom line: the millimeter adjustment is not as important as you might believe.

Saddle Fore/Aft Position

For years common thinking for saddle fore-aft positioning was determined by the knee over pedal spindle (KOPS) positioning. The KOPS fit process: place one foot forward (3 o’clock) with your crank arms parallel to the ground and then ensure that the forward knee cap is just over the center of the pedal (see picture below). For some riders this method will work well enough for a road or mountain bike fit but that is a “maybe” at best.

 
Illustration 8 – Knee over Pedal Spindle alignment

Many people use a plumb bob for this measurement (we did at one time). We found a laser to be easier and far more precise. While the right leg in the photo above is closest, the rider can spin the other leg forward and check the fore/aft on far leg as well without moving the laser. We also refer to this as a “hands free” technique.  With a laser, the fitter is able to make an adjustment or simply step back and take a look.  This is not possible with a weighted string hanging from the knee. Today we use this more to see if one knee is further forward than the other but NOT to check the actual saddle fore-aft position (especially on a tri bike fit).

Unlike road or mountain bikes, KOPS is NOT a starting point for tri bike fit. The modern method we subscribe to is a modified (but fairly close) Dan Empfield or Slowtwich approach. As mentioned above, my early influences come separate of Dan, having lived at the Olympic Training Center (OTC) in Colorado Springs when funny bikes were first being made.  I was also influenced by working with aerodynamic guru John Cobb. We put a lot of John’s information in our first bicycle fitting manual, possibly the first fitting manual on tri bike fit.  It is not that tri bike fitting was not talked about, but finding a manual for one was next to impossible.


Illustration 9 – A bike that may have been used in the 1984 Olympics – notice the small wheels

UCI Exceptions: Saddle Fore-Aft

There is an exception to the fore-aft saddle position for time trial bike fitting or for any bike that needs to be UCI legal. Because of this, it is actually easier to fit a time trial bike than it is a tri bike–one of the driving aspects or fit parameters is automatically set for you. We are not saying this is a good thing but rather an easier thing.

Illustration 10 – saddle set at 5cm behind the center of the BB

For USAC or UCI races or time trials, set the saddle height and put the nose of the saddle 5cm behind the BB and “Voila” you have your seat position for a time-trial bike. There are other parameters to follow. Just to make things more complicated, the UCI has a jig and your bike needs to be set up within the guideline of this jig (or template).  This resembles a template for a stock car.

To see what this jig looks like, here is a bike that is set up illegally for UCI/USAC racing.

Illustration 11 – Saddle too far forward for UCI and USAC racing.


Illustration 12 – UCI bike requirements.

Additionally, not shown in this illustration are several angles and positions of the cyclist on the bike that must adhere to UCI guidelines.

Learn More About Time Trial/Triathlon Fitting

If you are interested in learning more, please see our next Time Trial/Triathlon Fitting Article: Part 3: Upper Body Positioning.

How to Fit a Triathlon or TT Bike Part 3: Upper Body Positioning

triathlon contact points

Triathlon and TimeTrial/TT Fitting Part 3:  

Upper Body Positioning: Hands and Forearms

 

Shoulder and Hip Angles

The upper body is driven by two angles: the hip angle and the shoulder angle. Pinpoint these to angles and most people will feel comfortable in a triathlon bike position.  Your 3 landmarks for measuring hip angle are the (1) center of the bottom bracket (BB), (2) greater trochanter, and the (3) acromion process (AC Joint).

Hip Angle - TriathlonIllustration 13 – Hip Angle on a Triathlon Bike

If you are not sure where the AC joint is located, Arland Macasieb, a top triathlete and Red Level BikeFit Pro, points it out on the image below:

AC Join - Should Angle Triathlon

Illustration 14 – Notice the extension arm of the goniometer tool is in-line with Arland’s finger. To see more about Arland go here:  www.arlandmac.com

Shoulder Angle Triathlon

Illustration 15 – Ken Call DPT, a triathlete and BikeFit Pro, displays a 90° shoulder angle. Ken works for Therapeutic Associates out of Kennewick, WA. Here is a link to see more about Ken: http://www.therapeuticassociates.com/locations/washington/tri-cities/west-kennewick/kenneth-call/

Time Trial Bike Fit Should angle TriathlonTime Trial Bike Fit After Shoulder Angle Triathlon

Illustration 16 – Before and After

On the left, the triathlete demonstrates a hip angle above 100° and a shoulder angle greater than 90°.  On the right (post-adjustment) you see a hip angle closer to 100° and a shoulder angle closer to 90°.  We achieved this by moving the saddle forward (also raising it a few millimeters to compensate for the forward movement.  Anytime you move the saddle forward, you are also lowering or decreasing the distance to the pedals).  We lowered and shortened the stem and slightly decreased the reach on the extensions.  This took a few adjustments to the saddle, a couple at the stem, and one at the extensions.

This fit did not require a different set of bars; the only new piece of equipment needed was a stem. Of course, we used a sizing stem to help us get to this position. A sizing stem is a MUST when performing ALL bike fitting. If your fitter is not using a sizing bike, request a sizing stem for your fit.  Even though we did not change the bars in this particular fit, you may need to in order to achieve these angles. The bar change may include the base bar and the extensions along with forearm pads.

Another way to look at upper body fitting is to think of setting the 100 and 90 angles. Once completed, you simply rotate the entire upper body forward or backward. Perhaps this is one aspect where a fit bike like the Exit Bike may make this easier.

Hip and Shoulder Angles Triathlon

Illustration 17 – Rotating the entire body in unison on the bike

But wait!  Empfield says the shoulder angle should be close to 80°.   This is true–however, the protocols of F.I.S.T use different landmarks when measuring shoulder angle.  So yes, Slowtwitchers tend to look for 80°, but at BikeFit we use 90° for most bike fits.  Road, mountain, and triathlon remain consistent with our shoulder angle measurement, using the same landmarks. We do not change our number and landmarks for any single style of fit. The shoulder angle is basically the same.   In other words, we completely agree with each other.

Base Bar

Before doing all of the above, you need to select a base bar for your triathlon bike. The base bar used to be referred to as pursuit bars or cow horns. In case you haven’t noticed, we use a base bar or cow horns most of this time in this article.

Base Bar Width (Cow Horns)

The easiest way to select the handlebar’s width is to pick up different width bars in a bike shop and grab hold of them. Place your hands on each of the forward “reach” areas. Try both narrow and wide bars. Once you have the bars in hand, move them down near your waist, straight out in front of you, and then bring them toward your chest. Do this with a few bars and usually you’ll find one that feels better than the others. It may sound awkward, but it’s a great guide. If you are still unsure between two widths, put the bars up to your armpits and choose the ones that are most closely aligned.

Feet

Although this article focuses on the upper body, to learn about fitting the foot to the pedal, see our article on Road Bike Fitting or take a look at our BikeFit Manual: When the Foot Meets the Pedal.

Ready to get your Triathlon Bike or Time Trial Bike fit? Locate a BikeFit Pro.

Triathlon Bike - Hip and Shoulder Angles

Look Keo Pedal Wear

The equipment of the cyclist often tells a story.  You can acquire valuable information from looking at the components. However, expensive hardware and software will not find it–you must use your eyes! The popular Look Keo pedal is one of the easier pedals to discover uneven wear as the result of a common misalignment. Sometimes this wear can show up in just a few minutes of pedaling.

Where do You “Look” and Why?

For most, our feet do not meet flat or level with the pedal due to forefoot Varus. Notice the inside of the foot tilted up higher than the outside of the foot.

Pedal wear foot tiltlook keo foot tilt

In order to clip into the pedal, the foot is forced to be flat (the cleat will not engage the pedal if it is tilted). Therefore, your foot is forced to be level (parallel) with the pedal. How do we know? Look at your pedals and you will see the uneven wear. If the foot wanted to meet the pedal flat and level, the wear would be even, not uneven.

Take a gander at the Look Keo pedal below. Notice inside the red circle which pinpoints the pedal wear more in this area than anywhere else. The reason: the foot wants to be tilted in its natural position.

look keo pedal

 

Many stores and fitters own the expensive Keo Fit pedal but that only addresses cleat rotation to some extent.

What about the newer Look Keo pedals with the wider platform or the Look Delta pedals? You will still find the same wear underneath the front area of the pedal up toward the inside.

look keo pedal delta

The Solution

These example look pedals and many others like it show the need to add a wedge. Cleat Wedges® enable the cycling shoe to connect with the pedal naturally, by acknowledging the foot’s inherent angle.  This creates a neutral foot position throughout the pedaling cycle, resulting in greater comfort, power, and even pedal wear!  One of the most desirable and comfortable indicators is even pedal wear.

This pedal wear is evident in other pedal systems. See our blog post on Speedplay Pedal Wear for more information.