Phone camera setup for a bike fit: a repeatable side view
Prepare the bicycle, lens, framing and lighting before interpreting an angle. A practical recording protocol, not an instruction to change your fit.
Published 8 October 2026 · OpenBikeFit
Camera field guide
Square view. Repeatable placement.
Plan view: the lens faces the side of the bicycle.
Keep the whole moving rider in frame; mark both positions.
Schematic, not to scale or a calibrated room layout.
On this page
Understand before recording
Check camera readiness
Use the existing free workflow and read its source and scope checks; opening a page does not accept consent or verify a rider.
Open toolBefore asking what a bike-fit angle means, ask what the camera actually saw. A close crop can hide the ankle at the bottom of the stroke. A sharp but oblique view can change the projected relationship between hip, knee and ankle. A phone resting on a moving surface can produce different views during one clip. These are recording problems; moving a bicycle component to compensate for them would mix two different tasks.
This guide prepares a repeatable side-view recording of a stationary bicycle. It does not prescribe a rider position, certify the mounting of a trainer or tell you to adjust hardware. Follow the exact equipment instructions for supporting the bicycle. If it cannot be held securely for ordinary pedalling, stop preparation rather than substituting a precarious wall balance or an improvised moving recording.
Prepare the bicycle before the phone
Use the same bicycle, saddle, shoes, pedals and declared riding condition for the recordings you want to compare. Record the actual setup separately from a calculated target. A target in a calculator is not evidence that the bicycle was physically set to those coordinates. Avoid changing a component between two takes intended to describe one unchanged condition.
Check and record how the bicycle is supported and aligned. Axle height is a useful reference for documenting whether the bicycle is level; do not assume a trainer or front-wheel support automatically creates the same pitch as another setup. The point is a repeatable declared condition, not an app-generated guarantee of physical alignment. Keep the support method with the recording notes.
Position a fixed side view
Place the camera square to the side of the bicycle and keep it level. Adjust distance and height until the whole rider and bicycle fit with room around the moving limbs. The diagram is a plan-view explanation of the direction of sight, not a measured room layout or a universal distance requirement. Different lenses, devices and rooms require different placement.
Do not solve a cramped room by taking an oblique view and calling it equivalent. Move the camera or bicycle only while preparation is stopped, then assess the whole frame again. Record which side faces the lens. The near-side hip, knee and ankle should remain identifiable together. A far-side limb crossing in front of them can change tracking even when the picture looks sharp.
Choose framing and light together
Watch the entire cycle in preview: head, shoulders, hands, hips, knees, ankles and feet should remain inside the frame. A screenshot at one crank position cannot demonstrate this. Leave margin for normal motion rather than fitting the rider exactly to the edges. Choose a normal lens view and avoid a strongly distorted edge-of-frame perspective. Recheck framing after changing a lens, camera orientation or browser viewport.
Light the visible rider, not only the wall behind them. Reduce strong backlighting, deep shadows and visual clutter that conceals the limbs. Clothing and background should let the body outline remain distinguishable. Another visible person or a reflection can complicate a pose estimate. These are practical checks you can see; they are not a promise that the model will locate anatomical centres accurately.
Keep the riding condition explicit
Use a consistent hand position, resistance and ordinary pedalling condition for related takes. Record any meaningful difference instead of silently treating it as the same trial. A rider can change posture without a component moving, so changed joint angles do not by themselves establish a changed bicycle coordinate. Keep observed movement, recorded hardware and rider-reported experience as separate kinds of information.
Allow the rider and tracking preview to settle before the accepted recording. Getting on, reaching toward the phone or starting and stopping are not steady measurement cycles. OpenBikeFit checks capture quality and uses multiple clean cycles, but a passing technical gate cannot inspect the trainer, verify a component manual or establish what happened outside the camera view.
Record an independent second take
Mark the positions of the camera support and bicycle and preserve the lens, side, height, orientation and support method. Stop the first recording and begin a genuinely separate take without changing the declared setup. Reopening a clip, replaying it or copying a frame is not another observation. If something moved, describe a new condition rather than claiming an unchanged baseline.
The next take should answer whether the observation is repeatable under that protocol. Agreement does not certify absolute accuracy: an oblique camera can repeat the same projection error. Disagreement is a reason to review conditions and capture quality, not permission to select only the take that matches a preferred number. The separate repeatability guide explains that decision.
Know where this camera check ends
OpenBikeFit derives its side-view joint angles from image-plane points. A pose model can estimate depth-related information, but that does not turn this workflow into a physically calibrated multi-camera laboratory. The phone view cannot establish torque, component compatibility, a correct installation, a clinical diagnosis or an ideal position. Do not use a clean-looking overlay as proof of those outcomes.
The free readiness check is the next step when device support, permission, image quality or the local pose runtime is uncertain. It can require explicit camera access and downloads of self-hosted runtime resources; merely reading this article does not grant permission or start a recording. If no camera is available, use the public fictional analysis to learn what outputs mean, or record mechanical dimensions on the blank worksheet. Neither substitute is a real rider measurement.
Practical questions
Frequently asked questions
How far away should the phone be?
Far enough for the whole rider and bicycle to remain visible throughout pedalling with margin. Choose a repeatable, square side view appropriate to the lens and room; there is no single distance that validates every camera.
Can I record while riding outdoors?
This guide and the OpenBikeFit side-view protocol describe stationary, securely supported pedalling. A moving outdoor view is a different recording condition and is not certified by this workflow.
Does opening this guide start my camera?
No. This page is static learning content. Opening a tool and granting camera permission are separate choices, and reading the article does not save a fit or accept its scope.