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Bicycle Geometry Definitions:
Stack: Vertical distance from bottom bracket to head tube top
Reach: Horizontal distance from bottom bracket to head tube top
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Stack and reach are two key measurements that define a bicycle's frame geometry. Stack is the vertical distance from the bottom bracket to the top of the head tube, while reach is the horizontal distance between these same points.
The calculator uses simple coordinate geometry:
Stack = Head Tube Y - Bottom Bracket Y
Reach = Head Tube X - Bottom Bracket X
Where:
Explanation: These measurements help determine how a bike will fit a rider, affecting riding position and comfort.
Details: Stack and reach are critical for bike fitting. Stack affects how high or low the handlebars are relative to the saddle, while reach affects how stretched out the rider is. Together they determine the bike's overall fit and riding position.
Tips: Enter the X,Y coordinates of both the bottom bracket and head tube in millimeters. All values must be valid numbers.
Q1: What's a typical stack/reach ratio?
A: Road bikes typically have a ratio around 1.5:1 (stack:reach), while endurance bikes may be closer to 1.7:1.
Q2: How do stack and reach affect bike fit?
A: Greater stack creates a more upright position, greater reach creates a more stretched-out position.
Q3: Should I prioritize stack or reach?
A: Stack is generally more important for comfort as it affects neck and back strain. Reach can often be adjusted with stem length.
Q4: How do these compare to traditional measurements?
A: Stack and reach provide a more standardized way to compare bikes than seat tube length and top tube length.
Q5: What's more important for comfort?
A: Stack generally has a greater impact on comfort as it determines how much weight is on your hands and how much your back is bent.