Aerodynamic Bike Fit: "Oh yea, you're SO aero now." How do you know?

In cycling everyone wants the edge. The next new thing that gets your 10 more watts or saves you 10 watts at 40k and hour. The magic bullet. Well, spoiler alert, there isn’t one.
At Source Endurance, we measure things. If something is purposed to make a difference in your cycling, let’s check the science, read the studies, put it in your training and track the results. One thing that makes a huge difference is your bike fit. We have known since the beginning of cycling that a good fit makes you faster and more comfortable. Now there’s dozens of fitters offering “aerodynamic bike fits.” I’m not talking about a fitter and an engineer in a wind tunnel moving your around to shed drag. If you’re so lucky to find yourself in a wind tunnel, get all you can out of it, ask questions, shed drag.
If you read online about a local fitter offering an aerodynamic bike fit with a traditional fit platform, be skeptical. When you get on the fit bike or your bike is in the trainer, what is that fitter measuring to change you fit to be more aero? Even if you are willing to lower your comfort level to be more aerodynamic, how do you know the changes are in fact more or less drag? You don’t. Unless you are in a wind tunnel, as a fitter, I will not sit there and say “yea man lets slam those bars so you’ll be more aero” it’s just not objective.

Triathlete bike fit at Source Endurance Training Center of the Rockies.

In fitting, we progress the fit, on a fit bike, or a retro fit, through a protocol and the rider and fitter and fit tools all align in the end at the proper fit. When this is done right you land at the end of the fit and anything beyond that pretty subjective. Riders don’t usually self select positions that are physically aerodynamic. Even surprisingly most riders when you progress though the fit will mention wanting to be a bit lower for comfort, weight distribution, etc. Where there’s a line in my fitting practice is when we would push the rider away from a position that is deemed most comfortable and efficient to chase an aerodynamic goal that isn’t objectively measurable.
There are some common practices that would change drag objectively that we can follow when fitting. Get the cables out of the way. This is where fitting meets bike mechanic work but if you as a fitter knows what you’re doing around bike cabling and during your fit you expose cables as too long or find cables that can be hidden better, cable housing represents drag and poor aesthetics, getting those cables out of the way is never a bad idea. Helmet fitting for TT or Triathletes. This is a detail overlooked much of the time. Get the rider to bring in their TT helmet if they have one and make that part of the fit. You’re still not measuring drag but the helmet is part of the system in a TT fit for head position.
Aerodynamics is a huge factor in cycling and your fit is a big part of that aerodynamic equation. A good fit lands you near your aerodynamic potential with comfort and efficiency as a driver. Don’t fall victim to paying big bucks for an “aerodynamic bike fit” with no way to measure aerodynamics.

Learn more about the Source Endurance Training Center of the Rockies and our bike fitting philosophy here