Stack and Reach Fit Screen

Compare frame stack and reach with a caller-defined fit window.

Description

Bicycle stack and reach define frame geometry coordinates.

Bicycle stack and reach define frame geometry coordinates. A caller fit window can screen each coordinate separately.^[1]

Compare frame stack and reach with a caller-defined fit window.

When to use Stack and Reach Fit Screen

Use this tool to compare frame stack and reach with a caller-defined fit window.

Prepare the measured movement, timing, load or preassigned score requested. Keep protocols, units, paired measurements and caller-selected thresholds consistent.

How to use Stack and Reach Fit Screen and understand its results

Prepare the measured movement, timing, load or preassigned score requested. Keep protocols, units, paired measurements and caller-selected thresholds consistent.
Enter stackMillimeters, reachMillimeters, minimumStackMillimeters, maximumStackMillimeters, minimumReachMillimeters, maximumReachMillimeters using the field table and calculation rules, then run the tool.
Read stackFits, reachFits, geometryFits. 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
stackMillimeters	Measured stack (mm)	number	Required
reachMillimeters	Measured reach (mm)	number	Required
minimumStackMillimeters	Minimum stack (mm)	number	Required
maximumStackMillimeters	Maximum stack (mm)	number	Required
minimumReachMillimeters	Minimum reach (mm)	number	Required
maximumReachMillimeters	Maximum reach (mm)	number	Required

Enter finite measurements and ordered min/max bounds for both axes. Signed values are accepted. Return inclusive stack/reach gates and their conjunction.

fits=(stack in range) AND (reach in range)

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

Output field	Meaning	Value type
stackFits	Stack fits	boolean
reachFits	Reach fits	boolean
geometryFits	Geometry fits	boolean

json

{
  "input": {
    "stackMillimeters": 580,
    "reachMillimeters": 390,
    "minimumStackMillimeters": 560,
    "maximumStackMillimeters": 600,
    "minimumReachMillimeters": 380,
    "maximumReachMillimeters": 400
  },
  "output": {
    "stackFits": true,
    "reachFits": true,
    "geometryFits": true
  }
}

Limitations and assumptions

No rider geometry, stem, saddle or individualized fit recommendation is calculated.

Numeric inputs 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. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use Bike Saddle Inseam Fit: Estimate saddle height from inseam and a caller-selected fitting factor. For a complementary task, use Knee Over Pedal Offset: Measure knee-over-pedal-spindle horizontal offset at a specified crank position.

References

Stack and Reach Fit Screen — tool.io

Similar or alternative tools

Bike Saddle Inseam Fit
Estimate saddle height from inseam and a caller-selected fitting factor.
Knee Over Pedal Offset
Measure knee-over-pedal-spindle horizontal offset at a specified crank position.