Our methodology
BikeSize has no fit studio and no test lab. What it has is arithmetic, manufacturer data, and a set of rules about what counts as evidence. These pages write those rules down so you can check the reasoning behind a recommendation instead of taking it on faith.
The editorial policy covers who writes the site, which sources are acceptable, and how often pages get reviewed. The affiliate disclosure covers the money. Methodology pages cover the method itself: the formulas, the normalization rules, and the evidence hierarchy.
How BikeSize calculates bike size
Every formula behind the BikeSize frame-size and saddle-height calculators, the inputs each one takes, how accurate it is, and when to book a professional fitter instead.
Read itHow we normalize manufacturer sizing
How BikeSize reconciles brand size labels, keeps overlapping manufacturer ranges intact, converts units, and what it refuses to infer when a brand publishes nothing.
Read itHow we select and verify gear
The evidence hierarchy behind BikeSize product picks, the quarantine rule for incomplete safety evidence, and how affiliate links do and do not affect what gets recommended.
Read itHow we source and update product and geometry data
Where BikeSize geometry and product numbers come from, the provenance and confidence recorded with each one, how often they are rechecked, and how errors get corrected.
Read itHow our equipment and performance calculators work
The published models behind the BikeSize drivetrain, wheel, tire-pressure, power, calorie, and climbing calculators, the constants each one assumes, and where each estimate stops being reliable.
Read itFound an error?
If a formula here does not match what a calculator returns, or a size chart contradicts the manufacturer, report it on the public issue tracker. Reports are handled in the open so other readers can see what has been flagged. Corrections that affect a published number get made on the page and noted there.