Fixed Gear Dropout Movement Visualizer

Old Setup New Setup Axle Movement

Old Ring Teeth: 51 teeth Old Cog Teeth: 16 teeth

New Ring Teeth: 48 teeth New Cog Teeth: 21 teeth

Advanced Settings ▼

Chainstay Length (mm): 410 mm Wheel Size: Tire Size:

Dropout Slot Length (mm): 30 mm Crank Length (mm): 170 mm Chain Sag (mm): 16 mm

Chain Length Requirements

Old Setup Required: -

New Setup Required: -

Chain Length Difference: -

Axle Movement Analysis

Axle Movement Distance: -

Old Setup Position: -

New Setup Position: -

Dropout Utilization: -

Old Setup (Blue)

Gear Ratio: -

Gear Inches: -

Meters Development: -

Gain Ratio: -

New Setup (Green)

Gear Ratio: -

Gear Inches: -

Meters Development: -

Gain Ratio: -

Gear Comparison

Help Improve This Calculator

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Predicted Movement:

Actual Movement (mm):

Chain Age: Additional Notes (optional):

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Chain Length Formula: L ≈ 2 × S + (π/2) × (R + C) + (R - C)² / (4 × S) + sag² / (8 × S)
Where S = chainstay length, R = chainring radius, C = cog radius, sag = chain sag compensation