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Record on a trainer
Capture a side-view video while pedaling indoors. Stable framing improves BDC/TDC detection.
Generic bike-fit tools estimate. We compute measurement consistency on every analysis and show you a confidence score.
Most consumer bike-fit tools treat triathlon as one of several preset rider types. That often means aero geometry — high hands, forward saddle / steep STA, flat torso — gets scored with road-bike heuristics. The result can look “correct” on a single still while missing cycle-to-cycle consistency and triathlon-specific ranges.
Capture a side-view video while pedaling indoors. Stable framing improves BDC/TDC detection.
We locate bottom and top dead centre frames and aggregate angles over multiple pedal revolutions — typically in the 8–20 cycle range when the clip is long enough.
You get joint feedback tied to published knee ranges and coaching consensus for aero posture, plus a consistency score so you can see how stable the measurement was.
Shows how many cycles were scanned and how much BDC knee angles varied (standard deviation). A high score means the reported angle is repeatable — not a lucky single frame.
Knee (BDC): Holmes / Bini / Ferrer-Roca. Hip, torso, elbow (aero): F.I.S.T. protocol and triathlon coaching standards — kept as separate evidence categories. Methodology →
Shin/thigh pixel ratio at BDC is stored per session. Over time it supports personalized saddle/cleat context instead of one-size anthropometry assumptions.
Off-axis camera angle is a common source of fit error. Calibration checks flag wheel/hub geometry that suggests the bike is not square to the lens.
Built by Onur Kapucu — triathlon coaching background combined with software engineering. BikeFit AI is a practical tool for measuring position on a trainer, not a marketing claim about replacing a full studio fit.
Credit-based access for web analysis. Credits do not expire.
1 Coach Review + 5 Analysis Credits
In addition to AI analysis, triathlon coach Onur Kapucu personally reviews your fit results and sends a custom video/written evaluation.
Request Coach ReviewA stationary trainer (smart or basic) is recommended so the bike stays fixed in frame. Bluetooth power/cadence is optional telemetry, not required for angle analysis.
A typical clip is ~20–40 seconds of pedaling after you’re on the bike. Processing on the analysis backend usually finishes within about a minute depending on length and load.
Road and triathlon / TT modes. Triathlon mode uses aero-specific torso, hip, and elbow guidance; road mode uses road ranges.
Side view, full body visible, camera roughly level with the bottom bracket, bike square to the lens. Mark hubs / BB / saddle in calibration when you want cm saddle and KOPS.
It summarizes measurement consistency across detected pedal cycles (count + variability). Use it to decide whether to trust a single session or re-record with a longer, cleaner clip.