Bicycle Reach And Stack Calculator

Bicycle Geometry:

\[ \text{Reach} = \text{Horizontal distance from bottom bracket to head tube center} \] \[ \text{Stack} = \text{Vertical distance from bottom bracket to head tube center} \]

Calculated Reach:

Calculated Stack:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What Are Reach and Stack?

Reach and Stack are two key measurements in bicycle frame geometry that determine how a bike will fit a rider. Reach is the horizontal distance from the bottom bracket to the center of the head tube, while Stack is the vertical distance between these same points.

2. How Does the Calculator Work?

The calculator uses standard bicycle geometry measurements:

\[ \text{Reach} = \text{Horizontal BB to head tube center} \] \[ \text{Stack} = \text{Vertical BB to head tube center} \]

Where:

BB — Bottom bracket (the center of the crank axle)
Head tube center — The midpoint of the head tube where the fork passes through

Explanation: These measurements help determine the bike's handling characteristics and fit for the rider.

3. Importance of Reach and Stack

Details: Reach affects how stretched out you are on the bike, while Stack determines how high the handlebars are relative to your pedals. Together they influence comfort, handling, and aerodynamics.

4. Using the Calculator

Tips: Enter frame reach and stack in millimeters as provided by the manufacturer. These values are typically found in the bike's geometry chart.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical reach measurement?
A: Road bikes typically range from 370-400mm for medium sizes, while mountain bikes may be shorter (420-480mm for modern trail bikes).

Q2: How does stack affect bike fit?
A: Higher stack means a more upright position, lower stack creates a more aggressive, aerodynamic position.

Q3: Should I prioritize reach or stack?
A: Stack is generally more important for comfort (determines back angle), while reach affects arm position and handling.

Q4: How do I compare bikes using these numbers?
A: Compare reach/stack between bikes to understand how the position will differ. A bike with +10mm reach will feel longer.

Q5: Can I adjust reach and stack after purchase?
A: Yes, through stem length/angle, handlebar rise, and headset spacers, but frame measurements are fixed.