Reconcile one completed bicycle cadence-speed interval from whole-tooth gearing, measured loaded rollout, recorded speed, and observed distance/time.
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Inputs that matter
One de-identified completed owner, mechanic/coach or reviewed-training conventional external-chain cadence-speed interval; responsible record/revision/date/reviewer; exact bicycle/load/interval; direct-drive basis; installed chainring and selected rear-sprocket product/tooth evidence; exact driven wheel/rim/mounted-tire/pressure/load state; loaded rollout method; cadence source plus averaging/zero-exclusion semantics; completed speed source; independently observed distance/time source; sensor/device calibration; surface/condition; no-shift/no-coast/slip boundary; compatibility, installation/condition, tolerance/disposition, safety and review/retention records; whole tooth counts; measured circumference; completed mean cadence and reported speed; observed distance and elapsed time; user-owned speed tolerance; and an optional same-interval source plus cadence and speed
Output to expect
Selected direct ratio, measured development, reproduced wheel RPM, ideal no-slip speed in km/h, mph and m/s, completed reported-speed difference, independently observed distance-time speed and difference, plus optional same-interval cadence and speed differences
How it works
Validate every provenance field, positive bounded measurement, nonnegative tolerance and whole tooth count; divide front by rear teeth; multiply the measured loaded circumference by that ratio; multiply completed mean crank RPM by development and 60/1,000 for ideal no-slip km/h; divide observed meters by elapsed seconds and multiply by 3.6; convert km/h to mph with NIST's exact 1.609344 factor; require completed and observed speeds inside the user-owned tolerance; require optional source/cadence/speed all-or-none; and normalize only mathematical zero
Confirm that bicycle/load state, exact selected pair, conventional direct-chain path, driven wheel/tire/pressure state, loaded rollout, cadence and zero-exclusion basis, completed speed, observed distance/time interval, calibration and optional report all match. Another gear, interval, wheel state, averaging rule, shift, coast period or source revision needs another run.
Use the result only for one completed same-interval kinematic and transcription check. It does not model internal hubs, gearboxes, motors, belts or compound reductions; infer tire slip/deformation beyond recorded rollout; validate sensors, compatibility, installation, torque, adjustment, wear or condition; predict speed, power, terrain, wind, fatigue, pacing or performance; select cadence/gearing; diagnose discrepancies; or authorize training, purchase, service, safety or riding.
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Built around the job you need to finish
Reconcile one completed conventional external-chain cadence-speed interval against exact whole-tooth gearing, measured loaded rollout, a completed speed report and independently observed distance/time without predicting performance or prescribing cadence.
Mechanic auditing one cadence and wheel-speed interval
Replace a generic nominal-wheel formula with exact selected gearing, loaded rollout, device basis and same-interval evidence.
Freeze the bicycle/load/gear/wheel state, retain whole tooth counts and loaded rollout, then enter completed cadence, reported speed and independently observed distance/time.
Receives reproducible kinematic speed and signed differences inside the source-owned tolerance while calibration, compatibility, condition and service decisions remain external.
Coach reviewing averaging semantics
Prevent average cadence from one interval or zero-exclusion rule from being compared with another interval's speed.
Retain the same start/stop interval, cadence sampling and zero-exclusion basis, selected gear, no-shift/no-coast status, speed source and elapsed-time basis.
Can identify an arithmetic or transcription mismatch without receiving a cadence, pacing, power, fitness or training recommendation.
Owner documenting a device discrepancy
Avoid blaming GPS, a cadence sensor, wheel calibration, tire slip or component condition from an unbounded calculator output.
Record exact devices/calibration, loaded wheel state, distance/time source, tolerance and responsible reviewer, then optionally add one same-interval independent report.
Gets transparent differences and a clear escalation boundary rather than an unsupported diagnosis or permission to ride.
Authoritative checks for this tool
Outputs and checklists are planning aids. Review the linked current authorities and the records, terms, instructions, and requirements that apply to your exact situation before a consequential decision.
Retain one bicycle/load state, one continuously engaged conventional external-chain gear pair, one loaded wheel state, and the same start/stop interval for cadence, speed, distance, and elapsed time. Another gear, wheel state, interval, averaging rule, shift, or coast period needs another record.
Reproduce direct-drive development
Require verified whole front and rear tooth counts. Divide front teeth by rear teeth, then multiply the measured loaded wheel circumference by that ratio to reproduce meters traveled per crank revolution under the documented ideal no-slip basis.
development (m/crank rev) = measured loaded circumference (mm) ÷ 1,000 × front teeth ÷ rear teeth
Reproduce cadence-derived speed
Use completed mean crank-arm revolutions per minute from the named averaging and zero-exclusion basis. Convert cadence times development to kilometers per hour and report NIST-consistent mph and m/s conversions.
speed (km/h) = mean crank rpm × development (m/rev) × 60 ÷ 1,000
Reconcile independent observations
Divide the same-interval observed distance by elapsed time, compare that speed and the completed reported speed with the reproduced ideal speed, and enforce only the tolerance owned by the source record. Differences trigger review; they are not silently corrected.
Updated: August 2026
Example Scenarios
Reproduce a completed crank-cadence and wheel-speed report from the exact selected gear and loaded rollout, then compare it with independently timed distance.
Confirm that mean cadence, zero-exclusion, speed, distance, and elapsed time all describe the same no-shift/no-coast interval before using the record elsewhere.
Expose an out-of-tolerance difference without blaming GPS, rollout, sensors, tire slip, shifting, coasting, calibration, or component condition from arithmetic alone.
Common Mistakes to Avoid
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Entering a tire-label shortcut as measured circumference
✓
Retain the completed loaded rollout for the exact wheel, rim, mounted tire, pressure, load, surface, and method state.
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Mixing average cadence with another interval's speed
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Use the same start/stop interval, averaging and zero-exclusion basis, selected gear, wheel state, distance, and elapsed time throughout one run.
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Treating arithmetic agreement as a performance or safety approval
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Keep calibration, compatibility, installation, condition, discrepancy diagnosis, training, service, safety, and riding decisions with the responsible sources and reviewers.
FAQ
No. It reconciles one already completed interval. Cadence targets, gearing choices, pacing, power, terrain response, fitness, symptoms, accessibility, and training decisions require separate responsible review.
ISO tire and rim designations identify dimensions and product families, but installed circumference changes with the exact rim, tire, pressure, load, condition, and measurement method. Retain a completed loaded rollout for this record.
Cycling cadence is crank-arm revolutions per minute. Retain whether the source is instantaneous or averaged, the exact interval, sampling/recording basis, and whether zero cadence was excluded.
No. The implemented identity supports one conventional direct external-chain path only. Any hidden or additional reduction needs a source-owned model designed for that exact system.
Possible causes include nonmatching intervals, cadence averaging, wheel calibration, circumference state, distance or time measurement, shifting, coasting, tire slip/deformation, sensor behavior, transcription, or condition. The Tool reports the difference but does not diagnose it.
No. Agreement does not validate compatibility, installation, adjustment, torque, wear, wheel retention, sensor calibration, rider condition, traffic/course controls, compliance, or permission to ride.
About Reviewed Bicycle Cadence-Speed Interval
Reproduce one completed conventional external-chain interval from an exact selected gear, measured loaded wheel circumference, documented mean crank cadence, reported speed, and independently retained distance/time. The result checks kinematic arithmetic and transcription only; it does not predict performance or prescribe cadence, gearing, pacing, training, service, safety, or riding.
