1. What is a Bicycle Tire Pressure Calculator by Size?

Definition: This calculator estimates the optimal tire pressure based on tire width, rider+bike weight, and adjustment factors.

Purpose: It helps cyclists determine the proper tire pressure for their specific setup, improving comfort, performance, and safety.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P \) — Tire pressure (psi)
• \( C \) — Base constant (typically 100 psi·mm)
• \( W \) — Tire width (mm)
• \( A \) — Weight adjustment factor (psi per kg of total weight)

Explanation: The base pressure is inversely proportional to tire width, with additional pressure added based on total weight.

3. Importance of Proper Tire Pressure

Details: Correct tire pressure affects rolling resistance, grip, puncture protection, and ride comfort. Too high or too low can be dangerous.

4. Using the Calculator

Tips: Enter the base constant (default 100), tire width in mm, total weight (rider + bike) in kg, and weight adjustment (default 0.33). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why does tire width affect pressure?
A: Wider tires distribute weight over a larger contact patch, requiring lower pressure for the same support.

Q2: What's a typical base constant?
A: Most road bikes use 100 psi·mm, but this can vary (80-120) based on tire construction and riding style.

Q3: When would I change the adjustment factor?
A: Use higher values (0.4-0.5) for rough terrain or heavy loads, lower (0.2-0.3) for smooth surfaces or racing.

Q4: How do I measure total weight?
A: Weigh yourself with your cycling gear, then add your bike's weight (usually 7-12kg for road bikes).

Q5: Should front and rear pressures be equal?
A: No, rear tire typically needs 10-15% more pressure due to weight distribution (about 60% on rear wheel).