Road bike on a trainer
A road position on the hoods, with real fit findings: what to change, with the measurement each one fired on.
Scored on 7 of 7 measures — 100% of the rubric.
Measured against published ranges
Every target names where it comes from. A value just past the edge of a band is inside the method’s own error, so it is marked borderline rather than as a finding.
- Reference range
- Out of range
- Borderline
- In range
| Measurement | Yours | Vs reference | Status |
|---|---|---|---|
| Needs attention · 3 | |||
| Elbow angleRetul standard road fit window | 130.7° | 145–165° | Too low−14.3° |
| Shoulder angleBikeDynamics fit guidelines (upper arm to torso 85-90 deg); BikeFit (~90 deg) | 69.3° | 80–100° | Too low−10.7° |
| Trunk angleRetul; recreational rider norms | 35.5° | 40–55° | Too low−4.5° |
| In range · 3 | |||
| Knee at the bottom of the strokeRetul fit window; Burt 'Bike Fit' 2014 The top of this range is 9 degrees wider on this clip: filmed with the chainring away from the camera, the knee at the bottom of the stroke reads several degrees high, so a reading in the extra 9 is no reason to move the saddle. | 148.9° | 135–154° | In range |
| Knee at the top of the strokeRetul fit window | 70.4° | 65–75° | In range |
| Pelvic tilt ratio | 2.4 | 1.5–3.5 | In range |
Findings
- Elbow angle — 130.7°, against a reference of 145–165°
- Trunk angle — 35.5°, against a reference of 40–55°
- Shoulder angle — 69.3°, against a reference of 80–100°
What to change on the bike
In fitting order: each change moves the ones below it.
- bar position — Trunk angle is 35 deg (optimal 40-55 deg). Position is too aggressive -- raise stem spacers and stem angle for a more sustainable position.
One pedal revolution
Six positions either side of the top and bottom of the stroke, timed off the crank period rather than off frame counts.
What the recording cost the measurement
Verdict: fair. Every analysis says how the clip limited it, and what to change next time.
| Check | Measured | Target |
|---|---|---|
| Needs attention: How long the clip runs | 5.0 s | 8-15 s of steady pedalling |
| Good: How much of the frame you fill | 421 px tall (33% of the frame height) | 550 px or more — roughly two thirds of the frame height |
| Good: The angle you filmed from | side on (depth ratio 0.684) | filmed square-on to your side, so the joints move across the lens |
| Good: Which side of the bike you filmed | non-drive side (chainring away from the camera) | the same side every time — the two sides of one bike read the knee at the bottom of the stroke up to 9 degrees apart |
| Good: Which way you held the phone | portrait (720x1280) | portrait — a tall frame puts nearly twice the pixels on your legs |
Measured from a single side-on camera with 2D pose estimation. Only the near side of the body is measured; the far side is absent rather than assumed symmetrical. Reference ranges are efficiency targets from the literature, not diagnoses.
Film ten seconds and get your own
Side-on, phone upright, you filling the frame. Free account, no card.
Analyze your form — free