1. What is a Mountain Bike Frame Reach Calculator?

Definition: This calculator estimates the ideal frame reach for a mountain bike based on rider height and bike geometry factors.

Purpose: It helps cyclists and bike fitters determine the optimal frame reach for comfortable and efficient riding position.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( R \) — Frame reach (mm)
• \( L \) — Base reach (typically 400mm for modern mountain bikes)
• \( k \) — Height factor (typically 0.43 for most riders)
• \( H \) — Rider height (mm)

Explanation: The base reach provides a starting point, while the height factor scales the reach appropriately for the rider's height.

3. Importance of Frame Reach Calculation

Details: Proper frame reach ensures comfortable riding position, efficient power transfer, and better bike handling.

4. Using the Calculator

Tips: Enter the base reach (default 400mm), height factor (default 0.43), and your height in millimeters. All values must be ≥ 0, with height > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is base reach?
A: Base reach is the starting point for frame reach calculation, typically around 400mm for modern mountain bikes.

Q2: How is the height factor determined?
A: The height factor of 0.43 works well for most riders, but competitive riders may prefer values between 0.45-0.47 for a more aggressive position.

Q3: Should I convert my height from feet/inches to mm?
A: Yes, for accurate results, convert your height to millimeters (1 inch = 25.4mm).

Q4: What if my calculated reach isn't available on bikes?
A: Choose the closest available size and adjust with stem length and handlebar setup.

Q5: Does this account for different riding styles?
A: The defaults work for trail riding. Decrease height factor slightly for more upright positions (e.g., 0.40-0.42) or increase for aggressive riding (0.45+).