Triathlon T1/T2 Transition Tracker

Audit actual monotone triathlon swim-exit/bike-start/bike-finish/run-start timestamps and signed caller transition budget; no timing-chip offsets or assumed simultaneous-leg starts.

Description

Triathlon transitions are intervals between observed leg-boundary timestamps.

Triathlon transitions are intervals between observed leg-boundary timestamps. They need not coincide with the elapsed times of the race legs.^[1]

The returned values include Observed t1 seconds, Observed t2 seconds, Combined observed transition seconds, Signed transition time above caller target seconds. The How section below explains the calculation, input rules and interpretation.

When to use Triathlon T1/T2 Transition Tracker

Use Triathlon T1/T2 Transition Tracker when you need to evaluate the supplied records under the calculation and evidence rules below. No chip offset correction or assumed simultaneous leg starts is supplied.

Prepare the observed race, match or training records and the stated units. Supply independently verified rule editions, calibration tables and targets where requested.

How to use Triathlon T1/T2 Transition Tracker and understand its results

Prepare the observed race, match or training records and the stated units. Supply independently verified rule editions, calibration tables and targets where requested.
Enter observedSwimExitSeconds, observedBikeStartSeconds, observedBikeFinishSeconds, observedRunStartSeconds, callerCombinedTransitionTargetSeconds using the field table and calculation rules, then run the tool.
Read observedT1Seconds, observedT2Seconds, combinedObservedTransitionSeconds, signedTransitionTimeAboveCallerTargetSeconds. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
observedSwimExitSeconds	Observed swim exit seconds	number	Required
observedBikeStartSeconds	Observed bike start seconds	number	Required
observedBikeFinishSeconds	Observed bike finish seconds	number	Required
observedRunStartSeconds	Observed run start seconds	number	Required
callerCombinedTransitionTargetSeconds	Caller combined transition target seconds	number	Required

Enter nonnegative nondecreasing swim-exit, bike-start, bike-finish and run-start seconds plus nonnegative combined target. Return both transitions, total and total-minus-target signed difference.

T1=bikeStart−swimExit; T2=runStart−bikeFinish

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
observedT1Seconds	Observed t1 seconds	number
observedT2Seconds	Observed t2 seconds	number
combinedObservedTransitionSeconds	Combined observed transition seconds	number
signedTransitionTimeAboveCallerTargetSeconds	Signed transition time above caller target seconds	number

json

{
  "input": {
    "observedSwimExitSeconds": 100,
    "observedBikeStartSeconds": 160,
    "observedBikeFinishSeconds": 500,
    "observedRunStartSeconds": 550,
    "callerCombinedTransitionTargetSeconds": 100
  },
  "output": {
    "observedT1Seconds": 60,
    "observedT2Seconds": 50,
    "combinedObservedTransitionSeconds": 110,
    "signedTransitionTimeAboveCallerTargetSeconds": 10
  }
}

Limitations and assumptions

No chip offset correction or assumed simultaneous leg starts is supplied.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Per-KM Marathon Split Calculator: A variable-pace split plan uses each segment’s own distance and pace. Partial final kilometers remain explicit. For a complementary task, use Marathon Split Time To The Wall Calculator: A planned slowdown point separates two pace budgets. Its chosen distance need not mark physiological exhaustion.

References

Triathlon T1/T2 Transition Tracker — tool.io

Similar or alternative tools

Per-KM Marathon Split Calculator
A variable-pace split plan uses each segment’s own distance and pace. Partial final kilometers remain explicit.
Marathon Split Time To The Wall Calculator
A planned slowdown point separates two pace budgets. Its chosen distance need not mark physiological exhaustion.