Coach Tommy: Bike Fitter Bio

Comfort, Performance and Aerodynamics are not mutually exclusive.

Coach Tommy Johnson

Tommy Johnson


(469) 388-2701


Bike Fitter since 2015

Formerly a bike fitter at Tri Shop


Retul Level 2 Certified Bike Fitter

Slowtwitch Certified Bike Fitter

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See Tommy's Full Bio

Bike Fitting Philosophy

The human body is not symmetrical
There are differences from one side of the body versus the other side. For example, one leg might be slightly longer than the other leg. Meanwhile the bike is a highly symmetrical machine. Each side of the bike has the same dimensions. In addition, the cyclist is locked in place on the bike. Feet are clipped into the pedals. Pelvis is sitting on a saddle. Hands are griping the bars or elbows are on the arm pads.

In walking and even in running, the human body is free to move and adapt to the asymmetries.

The scenario where the asymmetrical human is locked into place on a symmetrical machine (the bike) can lead to discomfort and possibly overuse injuries. My bike fitting aims to understand the asymmetries in the cyclist’s body and adapt the bike and other equipment to accommodate these asymmetries.

Comfort and Performance are not Mutually Exclusive
There seems to be a misconception in the cycling and triathlon community that a high-performance bike position is uncomfortable. On the contrary, a bike position that maximizes performance should also be comfortable. It is hard to produce a lot of power or maintain an aerodynamic drag minimizing position if you are uncomfortable.

Performance = aerodynamics + power + comfort

My Bike Fits Conform to Orthodoxy
Orthodoxy: authorized or generally accepted theory, doctrine, or practice.

In bike fitting, as with most anything in life, there are generally accepted guidelines or norms within which most cyclists’ bike fits will fall. My bike fits seek to put the cyclist within these guidelines. Dan Empfield of Slowtwitch fame wrote an article on bike fit orthodoxy. I attended Dan’s FIST bike fit school and I learned about bike fit orthodoxy. Retul also preaches bike fit orthodoxy but in a slightly different way. The Retul technology measures the cyclist and the bike. There are orthodox ranges for these measurements within which most cyclists will fall. As a bike fitter, I better have a particularly good reason for a bike fit to fall outside these ranges.

My Perspective
My background is engineering. I spent many years working in an engineering field using math and science to solve problems. I believe this gives me a unique perspective on bike fitting. I approach bike fits as an engineering problem to be solved.

My Bike Fitting Process
Below is an outline of my bike fit process.

Cyclist Interview
My fit process starts with a cyclist interview. Here I seek a better understanding of the cyclist.

  • Cyclist history
  • Types of bike riding – tri, road, mtn, etc.
  • Cyclist goals – lifestyle, race or event goals
  • Cyclist injury history – current injuries, past injuries, surgeries
  • Cycling discomforts
  • Goals for the bike fit

At this time, before any changes are made, I will record video and make initial assessments of the cyclist’s bike fit.

Physical Assessment
The physical assessment is a process I use to understand the cyclist’s unique physical attributes. Assessments are made on:

  • Mobility
  • Flexibility
  • Strength
  • Leg Length Differences
  • Foot Structure
  • Pelvic Structure and Alignment
  • And other attributes

These assessments inform my decisions to change the bike setup.

Shoe and Cleat Adjustment
I spend a lot of time on the shoes and cleats. This is an important step that I think many cyclists do not give a lot of thought to. The shoe and cleat are locked into the pedal. The foot is inside the shoe. I want to bring the pedal/shoe up to the cyclist’s foot instead of having the cyclist’s foot collapse onto the shoe. Various wedges, shims and insoles are used to insure a stable and level surface is provided for applying power to the pedal.

Virtually every cyclist should have custom molded insoles. At this point I will mold Foot Balance insoles and install in the cyclist’s shoes.

Bike Adjustments
Finally, I get to making changes to the bike. The first thing we decide on is a saddle. If the cyclist’s current saddle is comfortable and his hips are stable, then we stay with the current saddle. If the saddle is uncomfortable then we will try a series of saddles that match his sit bone width previously measured in the physical assessment. Then we move on to making other adjustments to the bike. I use Retul motion capture technology to inform and confirm the changes made to the bike. Both left and right sides are measured because humans are not completely symmetrical. During this step video is recorded from the side and front of the cyclist.

Bike Measurements
After all adjustments to the bike are made then I digitally measure the bike. The bike measurements are included in the bike fit report sent to the client.

Fit Report
A comprehensive bike fit report is emailed to the client. The bike fit report details all aspects of the bike fit just completed.


I highly recommend Tommy. He is professional, knowledgeable and has all the high quality/ up to date equipment so that your fit on the bike is spot on. In addition to bike adjustments, Tommy made me custom insoles and placed shims on my cleats which made a major improvement. He is methodical with making adjustments and didn’t try to dazzle me with unnecessary chit chat about his profession. And his online site makes it super easy to schedule an appointment and understand what to expect. Thank you Tommy!


A friend gave me their old road bike, and after a few weeks on it, I was experiencing odd pains and tingling toes. Though it was nothing I’d ever considered before, I took the advice of someone to get Tommy to do a bike fit. What an excellent investment! First of all, even though I felt like Goldilocks, I tried a variety of saddles and found just the right one. He was patient while I tested each and used the spin time to give me pointers on form and take bike measurements. As a new cyclist, his form tips were invaluable coaching. Tommy also focused on my cleat adjustment to prevent me from losing feeling in my toes. I was impressed with his setup and the precision he took for every detail and seemingly minor adjustment.


Good quality service, Tommy was great and very professional. He explained all the adjustments we were making and made sure I was as comfortable and aerodynamic as possible. After the bike fit I immediately received a 16 page document with all sorts of data and information regarding my fit. Highly recommended!


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