How to get a good bikefit

29 November 2023
Even if you’re sure that your chosen bikefitter knows what she’s doing, the result may disappoint if you don’t.
drawing demonstrating horizontal chain stay length measurement
Often, I hear that people don’t want to spend money and time on bikefit arguing that two different fitters produce different results — so what’s the point than. I’m a proponent of a professional fit: I was surprised to learn a couple of things about how my body interacts with the bike at my first session, even though I had cycled for over 20 years by then.

A human body have bigger tolerances than bike components, but the significant differences in bikefit numbers may be because one doesn’t communicate with the fitter to explain what they want/need — if they even understand that themselves in the first place. It’s like coming to a doctor or a lawyer. They can only help you if you properly describe the problem and are involved in the process.
drawing demonstrating auxiliary chain stay length measurement
1. Understand your goal

I’d say that there are three popular goals:
• improve performance, in general or for a particular event/discipline,
• get rid of a certain pain/fatigue point or deal with an injury,
• make sure the fit is correct and won’t create problems in the future.

Listen, even “I want to look cooler on my bike” is a valid goal — just don’t forget to actually tell it to the bikefitter. Be honest with her and yourself, that’ll help a lot.
track bicycle with short chain stays and split seat tube
2. Decide how far you’re ready to go

There are two schools of thought in bikefitting: either to fit a bike to the person, or a person to the bike.

In first case, you’ll be put on a “mule” — an apparatus that allows infinite and unrestricted adjustments. After finding the best body position in space, you’d then need to find a bike allowing to recreate it. This is only possible if the fitter actually has the mule.
road bicycle with short chain stays and split seat tube
In second instance, you’ll come to the fitter with your own bike and you’ll try to adjust it to achieve the best result possible considering the limitations of your bike’s geometry and components.

2.1. Additional costs

Keep in mind that some components could be changed — that would usually be: saddle/seatpost, stem/bars, shoes/pedals/cranks. Oftentimes, the bikefitter will have some stock of her favourite parts (and we’ll assume that’s for their properties and not for her good markup on a low cost of supply). You should decide for yourself how much you’re ready to spend to achieve an optimal result.
close-up of road bicycle with short chain stays and split seat tube
Also, there is a hybrid approach where before buying a new bike, you come to a “sizing” session where the fitter evaluates you approximately and advises on which bike in what size to purchase, after which you come to the full “fitting” session. In my experience, that doesn’t always work well.

If I was buying a $$$$ bike and not sure the size/fit, I’d rather spend a couple of hundreds for a full bikefit beforehand rather than get a wrong size and regret it. Let alone that swapping components to get a good fit after the quick-and-dirty sizing may happen to be more costly than to come to an additional session with the bike (which would usually be heavily discounted).
bicycle with dropper seat post
2.2. Extra effort

Your body changes with time and training. Again, there are two approaches: let’s name them the pure fit and physio-based.

In the latter the fitter tries to apply her knowledge of physiotherapy to understand what you can achieve with your position on the bike. If you happen to deal with this kind of fitter, decide if you want to do non-cycling exercise such as yoga or weightlifting to improve your flexibility and/or strength. If you’re not ready for that, tell her. Otherwise, you may get a fit suitable to your better, but not actual, self.
bicycle with thin seat tube and integrated seat post
The pure fitting approach is not to try and change the cyclist, but to merely fit the bike to their body as it is. This doesn’t cancel the fact that the body will change (hopefully, to the better :)

3. Be open to a relationship

Whichever approach, a good fitter will have a vision of how your bikefit could develop with time. If you’re rather new to the sport, you’ll likely not only get stronger on pedals (with less pressure on the saddle), but also stretch out farther and lower. If you are a mature and seasoned cyclist, it may be that your power and flexibility will, vice versa, somewhat decrease with age.
bicycle with bent and slack seat tube
Anyhow, a good bikefitter will provide you with a sheet describing the result of the fit in words and numbers. Whether you keep working with her, or try another fitter for your next session for a second opinion, or learn how to adjust the bike to your changing situation yourself — remember that bikefitting is not a one-time endeavor, but a continuous process.

Be fit and fitted!