I’m sure I’m like most fitness cyclists when I say I think my bike fit is perfect for me. I mean, I’ve been riding for years with no significant pain or discomfort. I’ve had the occasional hot spot on my feet, the occasional numbing of the nether regions but I don’t get these sensations all the time. I’ve been online reading and applying the various bike fit philosophies and trends. I’ve paid to have the typical “eye-ball” static bike fit with the plum bob put on my knee, etc. However, I’ve always had these lingering questions that I couldn’t ignore;

  • Can my fit be better and if so will it make me a more efficient / faster rider?
  • Am I fitted properly for the most efficient cycling based on my bike choice and my body composition?
  • How do I know for sure that I’m fit properly based on someone “eyeballing” my position? I mean honestly, they could be off by 2-10mm with my seat post or my saddle position for all I know. How do they know the perfect angle just by looking at me?

My desire as a serious fitness cyclist was to know; once and for all, what is the best bike setup was for me? All this second guessing made me crazy so I decided that I would finally shell out the money for a Retul bike fit. I reached out to my local Retul bike fitter Jim Cunningham at Greenville Cycling & Multisport to setup a date.

  • So what is a Retul Bike Fit?

    The Retul bike fit is actually a complex analysis, which consists of 3D infrared data capture. This data capture, via infrared tracking, provides a highly accurate means of measuring a rider to their bike based on their PERSONAL physical make up. This is important to note; it’s based on your own unique physical build and measurements. You won’t see any traditional bike fitting tools like a level, a goniometer, plum bob or measuring tape. This is all done virtually inside the computer using some very cool tools.

  • What is the cost?

    This was my biggest question. The first thing you need to know is that a Retul bike fit is typically higher in cost when compared to a traditional “eyeball” fitting. The average Retul bike fit costs around $250 to $275 for a single bike. In my case I own 8 bicycle and wanted to get fit for 6 of them. 1 of the 6 bikes was a TT bike and was Retul fit completely independantly of the 5 other road bikes for obvious reasons. I was able to discuss my needs with Jim @ GCM and he was able to come up with a plan where we could simply transfer the measurement from one of the 5 bikes that we could call the “baseline” and transfer those measurements to the other 4 bikes. We would then check my position in 3D (we’ll get to that later) on each bike and make whatever changes were necessary. Rinse and repeat until each bike was properly dialed in.

  • How long does it take and what do I need?

    A Retul bike fit will take around 2-2.5 hours. Make sure to bring your shoes, your favorite pair of riding short/bibs and a sleeveless shirt or jersey and maybe a snack with water. You’ll need a sleeveless shirt because of the amount of LED data point sensors that will be placed on your body during the fit.

We’re ready to get fit:

  • Step 1: The rider interview.

    The first thing Jim will do is get to know you, the rider, better. He will ask you what your goal for riding is. Question will be asked such as; are you racing? Are you riding for fitness? How often do you ride? Are you hurt or limited in any way?

  • Step 2: Physical Assessment:

    The second step in the fit is a short physical assessment. The physical assessment consists of getting to know the rider’s anatomical and physiological makeup. This assessment will also identify any limitations you may have such as flexibility, movement, etc. In my case Jim sat me up on what appeared to be a small massage table. He checked my flexibility in my quads, hips, etc. Later he had me stand in front of him to check posture, balance, alignment, symmetry and a number of other things that I wasn’t quite sure he was looking for. Later on in the bike fit he and his assistant entered all this information into the Retul software to be presented in the final bike fit report. (Click do view example bike fit report).

  • Step 3: The Dynamic Fit:

    This is where the magic of the Retul bike fit comes alive. As I was warming up Jim started placing these velcro patches all over me. Patches were placed on my shoulders, elbows, wrist, legs, ankles and hip. This is why a sleeveless jersey is needed. These patches would hold the infrared “nodes” that the computer would use to make up my dynamic 3D model. The dynamic fit uses both 2D and 3D data to analyze the motion of you on your bike.

    The 3D dynamic fit process is the big difference, it’s what’s used to make the fit decisions. The 3D dynamic fit is a big difference when compared to the traditional static bike fit. You constantly pedal while the computer is reading these “nodes” and creating a wireframe model of your position in real time. During the data gathering process I was asked to pedal at around 80rpm for about 2 minutes. After each 2 minute data gathering session, we’ll call these a “data cycle”, the information was presented to me in a chart that displayed my numbers and compared them Retul’s “acceptable” numbers. Numbers that were displayed in RED were considered out of range. Numbers in GREEN were considered acceptable. The goal was to get all the various meausing points to GREEN. So we would start a new “data cycle” and repeat this process as necessary until all idenfitifed measurements were GREEN or as close to GREEN as possible.

    While gathering all these data points during the “data cycle” phase Jim was also taking note of all the parts, pieces, sizes, length that made up my bicycle. Jim noted the bike make, model size. He noted the stem, the crank size, the crank length, handlebar make, model, width, drivetrain. It’s all captured and noted during the bike fit and again presented in the final Retul report (Click here for example Retul report).

  • Step 4: Technical Analysis:

    The technical analysis which is part of what I call the “data cycle” process is used to ensure that the rider is fit properly but also to ensure that you’re moving well on the bike and that you’re comfortable. Again the goal is to try to get all your measuring points within an acceptable range within the Retul software.

    The Retul software won’t tell you when you’re comfortable so some of the fit process is a little rider subjective. There were certain times during the fit process where I didn’t feel as comformtable on the bike as i was used to but I also knew this was a new position on the bike for me. I didn’t want to confuse my possible sensation of discomfort for unfamiliarity so I decided I’d do my best during the bike fit to get all my numbers within Retul’s acceptable range. Various items are tracked during the technical analysis like knee tracking, pelvic stability, closed leg angle, open leg angle and so much more can all be viewed and analyzed. The goal is to get your riding position within an ideal angle range within the Retul software. Any changes to your saddle, stem, seat post, bars are made during this analysis. If changes were made the “data cycle” capture process would start over and rechecked against the Retul software’s nominal angle positions. We performed maybe 3-4 “data cycles” per bicyle before I was almost all in range of Retul’s acceptable range. In my opinion you can’t really get this type of accurate information from a static bike fit. An example, I was able to see in realtime my knee tracking. My left knee was not parallel to the bike when pedaling and would flair outward unlike my right knee which was perfect.

  • Step 5: “Zin” the bike:

    This, in my opinion, was one of the coolest thing to watch after my bike fit. As if being hooked up to about a dozen infrared nodes wasn’t enough, I was about to see my bike be 3D measured and stored so it could be analyzed against my position. The “Zin” process takes all the contacts points of the bicycles and places them into the Retul software. The software then will generate all the measurements between these points and create a model of your bicycle. The benefit of “Zinning” the bike is so that at any time you can get the position back if changes are made to the bike.


My bit fit took about 4.5 hours due to the number of bikes I brought in. I felt like a one man bicycle team. I had 3 bikes on the top of my CRV and 3 bikes in the back. Yes a CRV can hold 6 bikes rather easily, but I digress. Seeing each bike measured, photographed, adjusted, “zinned” took a great deal of time. In my case, the adjustments made to my bicycles consisted primarily of seat post height being raised and the saddle being moved forward much more than I would have ever guessed. I use the exact same saddle for all my bikes, the same Speed Play pedals. Had I not had the same saddle and pedals the adjustments probably would have been very different for each bike.

The immediate benefits of having a Retul bike fit are not yet known. While only slight adjustments were made on my bikes I can still feel a difference when riding. I now sit over the crank a bit more than I did before and the power transfer seems a bit improved. I’m still getting used to the new position of the saddle adjustment. As of this writing I’ve been able to ride all 6 bikes and honestly they all feel just about the same when mounted. This is a good thing because all 6 bikes have the exact same measurements. I now know that I have one of the most accurate bike fits available for all my bikes. I have a detailed Retul report with all the data that was collected for later use should I need to make any changes.

In my mind a Retul fit was time and money well spent. I spend countless hours and thousands of miles on my bike each year. The initial cost for a Retul bike fit is an investment in my opinion. My logic has always been if the bike fits well you’ll want to ride that bike, if it doesn’t fit well you won’t. For all the countless hours I spend riding both indoors and outdoors the last thing I want to be is uncomfortable on my bike and less efficient. A Retul bike fit can make you a more efficient, faster and more comfortable rider. Next time you’re thinking of buying a piece of equipment to improve your time or speed ask yourself, “Am I riding in a position that allows all the gear I own to perform at their maximum?” You be surprised to find out the answer.