METHOD · DIFFERENCES IN SCOPE

Three different services are advertised under the same word.

Two riders ask for a bike fit and pay a similar figure. One is measured for twenty minutes and gets the saddle raised. The other has strength per leg, joint ranges and segment lengths recorded before the bike moves at all. Both leave with a receipt that reads the same, and only one of them knows why their position is what it is.

Dimensioning, adjusting and assessing are three different questions.

The three questions

Each process answers one question, and none of them answers the others.

The depth of an intervention does not follow from the word that names it. It follows from what is assessed, who interprets it, which instrument is used and whether the change is verified afterwards.

01

Bike sizing

Dimensions

Which bike, size or geometry is compatible with this person?

The fit between a person and a frame.

  • Height, inseam and segment lengths.
  • Stack, reach and the rest of the frame geometry.
  • Databases of models, sizes and adjustment ranges.
  • A sensible starting configuration.

What it does not resolve: It does not say how your body behaves while pedalling, or why something hurts. It can be digital, automated and very precise, and still be dimensioning.

02

Bike fitting

Adjusts

How should this bike be configured for this rider?

The interaction between the rider and the bike they already own.

  • Saddle height, setback and tilt, and saddle choice.
  • Bars, stem, levers and the rest of the cockpit.
  • Cleats, foot support and crank length.
  • Observing the position and adjusting during the pedal stroke.

What it does not resolve: Its depth varies enormously: two services advertised under the same word can last twenty minutes or three hours. The commercial name tells you nothing about the scope.

03

Biomechanical assessment

Assesses, interprets, intervenes and verifies

What can this body do, and which configuration follows from that?

First the cyclist as a biological and mechanical system. Then the interaction with the bike.

  • History, injury background, training load, discipline and context.
  • Structure and posture, asymmetries and segmental relationships.
  • Mobility, joint range and strength measured side by side.
  • Anthropometry under protocol, pedalling kinematics and an intervention verified afterwards.

What it does not resolve: It is not a label you earn by buying a device. Without history taking, functional measurement and a later check, it remains a well-instrumented adjustment.

The short version

Bike sizing dimensions. Bike fitting adjusts. Biomechanics assesses, interprets, intervenes and verifies.

Technology can take part in all three. A simulator, a laser, a sensor or a trained model serve dimensioning as readily as assessment, and owning them does not by itself determine the depth of the process. What determines it is the question asked before the machine is switched on.

Technology measures. Training allows interpretation. Method integrates. Verification demonstrates.

Side by side

The same six rows, for the three processes.

Comparison between bike sizing, bike fitting and biomechanical assessment
CriterionBike sizingBike fittingBiomechanical assessment
Object of studyThe frame and its compatibility with a set of body measurementsThe bike you already own and its contact pointsThe cyclist first, the bike second
Typical momentBefore buyingAfter buyingEither, depending on what limits the case
What is measured on the bodyLengths and proportionsPosition and, depending on scope, basic mobilityHistory, posture, mobility, strength, anthropometry and movement
What it producesSize, compatible model and a starting configurationAn adjusted, reproducible configurationA diagnosis, a reasoned intervention and a verification
How it is checkedChecked when the bike is builtChecked during the session itselfMeasured again afterwards, under the same protocol
ONE serviceBIKEFINDER 3D · GURUIncluded within BIKEFIT 3DBIKEFIT 3D · GURU, with the body assessment first

The table describes processes, not providers. One professional can offer all three, and a case commonly starts in one and ends in another.

If you cannot tell which of the three applies, that is the consultation.

Diagnosis One orders the case before you spend on the wrong route, and puts in writing what gets assessed and why.

Frequently asked questions

Questions people ask us.

Is a bike sizing done with software and lasers already a biomechanical assessment?

Not necessarily. The instrument does not define the category of the process: what defines it is what gets assessed, who interprets it and whether the change is verified afterwards. A bike sizing can be digital, automated and very precise at dimensioning, and still answer the sizing question, which is about compatibility rather than function.

So a bike fit is not worth having?

It is, and for many riders it is exactly what they need. Someone without symptoms who changed saddle and wants their height back does not need a full functional assessment. The problem is not that short adjustments exist: it is that they are advertised under the same name as a process four times longer, so anyone comparing two quotes cannot tell what they are comparing.

Do you need a university degree to do bike fitting?

No, and ONE does not claim otherwise. There are fitters without university training who have excellent judgement and many hours of craft. What training changes is what can be interpreted: reading a strength asymmetry, a limited joint range or a previous injury and deciding what to do about them takes a base that is not improvised. The bounded claim is this one: not every bike fit constitutes a biomechanical assessment.

How do I compare two quotes that carry the same name?

With four questions: what is measured on the body before the bike is touched, who interprets those measurements and with what training, whether the change is tested under load or only at a standstill, and whether there is a later check against the starting measurement. All four can be asked in writing before booking, and they separate more than price does.