Bike Tire Size Conversion Calculator

ETRTO Equivalent Formula:

\[ \text{Equivalent (mm)} = \text{rim (in)} \times 25.4 + \text{width (in)} \]

ETRTO Equivalent (mm):

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1. What is a Bike Tire Size Conversion Calculator?

Definition: This calculator converts traditional bike tire measurements (in inches) to the ETRTO (European Tire and Rim Technical Organization) standard in millimeters.

Purpose: It helps cyclists and mechanics accurately compare tire sizes across different measurement systems.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \text{Equivalent (mm)} = \text{rim (in)} \times 25.4 + \text{width (in)} \]

Where:

Equivalent (mm) — ETRTO standard measurement
rim (in) — Rim diameter in inches
width (in) — Tire width in inches
25.4 — Conversion factor (inches to mm)

Explanation: The rim diameter is converted to millimeters and the tire width is added to get the ETRTO equivalent.

3. Importance of Tire Size Conversion

Details: Accurate size conversion ensures proper tire fit, compatibility with rims, and optimal performance and safety.

4. Using the Calculator

Tips: Enter the rim diameter and tire width in inches. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is ETRTO?
A: The European standard for bicycle tire and rim sizing that provides precise measurements in millimeters.

Q2: Why convert to ETRTO?
A: ETRTO provides more accurate and consistent sizing than traditional inch-based measurements which can vary between manufacturers.

Q3: How do I measure my rim diameter?
A: Measure the bead seat diameter (where the tire sits) in inches.

Q4: What about tire width variations?
A: Actual mounted width may vary based on rim width and pressure. This calculator provides the theoretical equivalent.

Q5: Can I use this for all bike types?
A: Yes, it works for road, mountain, and other bicycle tires when using inch-based measurements.