Examples
Examples
Try the starting example
- Original stem centre length (mm)
- 100
- Original absolute angle above horizontal (degrees)
- 0
- Candidate stem centre length (mm)
- 100
- Candidate absolute angle above horizontal (degrees)
- 60
- Candidate horizontal projection (mm)
- 50
- Candidate vertical projection (mm)
- 86.60254
- Horizontal contact-point change (mm)
- -50
- Vertical contact-point change (mm)
- 86.60254
Try another scenario
- Original stem centre length (mm)
- 100
- Original absolute angle above horizontal (degrees)
- 0
- Candidate stem centre length (mm)
- 100
- Candidate absolute angle above horizontal (degrees)
- 0
- Candidate horizontal projection (mm)
- 100
- Candidate vertical projection (mm)
- 0
- Horizontal contact-point change (mm)
- 0
- Vertical contact-point change (mm)
- 0
Calculation method
Calculation method
Candidate horizontal projection (mm)
Candidate length×cos(candidate absolute angle).
Candidate vertical projection (mm)
Candidate length×sin(candidate absolute angle).
Horizontal contact-point change (mm)
Candidate x−original length×cos(original angle).
Vertical contact-point change (mm)
Candidate y−original length×sin(original angle).
Symbols and units
- a
- Original stem centre length (mm)
- b
- Original absolute angle above horizontal (degrees)
- c
- Candidate stem centre length (mm)
- d
- Candidate absolute angle above horizontal (degrees)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions & limits
Assumptions & limits
- Absolute angles are measured in the bicycle side view from forward horizontal. A manufacturer’s nominal stem angle may use a different convention; this tool does not convert steerer-relative markings or prescribe a fit.
Are these inputs private?
These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.
Further reading
OpenStax: Euclidean geometry and trigonometric identities ↗
Background reading; this does not imply endorsement or independent review of SumFizz.