# Bicycle Saddle Height Calculator (LeMond & Hamley Rules)

> Bicycle Saddle Height Calculator (LeMond & Hamley Rules) is a paid API for AI agents from bike-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Calculates recommended starting saddle height from inseam using the LeMond (×0.883) and Hamley (×1.09) formulas, plus the Holmes knee-angle range check.

## Facts

- Endpoint: GET https://bike-calc.x402tookit.com/saddle-height?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bicycle-saddle-height-calculator-lemond-hamley-rules-bba32d15
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7Iyqba67ZjRyzEFKrp1op

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability bicycle-saddle-height-calculator-lemond-hamley-rules-bba32d15
```

Example prompt: My inseam is 84 cm — can you calculate my recommended starting saddle height using both the LeMond and Hamley methods, and tell me the Holmes knee-angle target range?

## When to prefer this

Use this endpoint when you need a quick, formula-based starting saddle height recommendation from inseam alone, following the two most widely cited cycling fit rules (LeMond and Hamley), and want the Holmes knee-angle reference bundled in one call. Prefer this over a full professional bike-fit service when the user wants a self-service first estimate before visiting a fitter, or when building an automated bike-fit onboarding flow.

## Known failure modes

- Missing required 'inseam' query parameter returns an error
- Non-numeric inseam value causes a validation failure
- Extremely small or large inseam values may produce physically implausible results
- Invalid unit value (anything other than 'cm' or 'in') may default to cm or error
- Payment failure (x402) prevents access to the endpoint

## How this service works

Starting saddle height from inseam by the LeMond (0.883) and Hamley (1.09) rules, plus the Holmes knee-angle check.

## Output

Returns the recommended saddle height in both cm and inches under both the LeMond (inseam × 0.883) and Hamley (inseam × 1.09) methods, the difference between the two, the Holmes target knee-angle range in degrees, suggested step adjustment values in mm, the original inseam in both units, and a disclaimer/summary. Also includes a verdict and degraded/not-checked flags.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "inseam"
     ],
     "properties": {
      "unit": {
       "type": "string",
       "description": "cm (default) or in"
      },
      "inseam": {
       "type": "number",
       "description": "Inseam length (crotch to floor, barefoot)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "hamleyCm": {
       "type": [
        "null",
        "number"
       ]
      },
      "inseamCm": {
       "type": [
        "null",
        "number"
       ]
      },
      "lemondCm": {
       "type": [
        "null",
        "number"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "hamleyInches": {
       "type": [
        "null",
        "number"
       ]
      },
      "inseamInches": {
       "type": [
        "null",
        "number"
       ]
      },
      "lemondInches": {
       "type": [
        "null",
        "number"
       ]
      },
      "stepAdjustMm": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "number"
       }
      },
      "hamleyMinusLemondCm": {
       "type": [
        "null",
        "
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bicycle-saddle-height-calculator-lemond-hamley-rules-bba32d15/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bike-calc.x402tookit.com](https://www.zero.xyz/host/bike-calc.x402tookit.com/llms.txt)