Welcome to the Geek Sheets
- We’ve designed these aero tools to turn the numbers into real-world savings.
- Dive in, see what they show, and find out how many watts you’ll need for your next PB.
- You’ll find a glossary of terms at the bottom of the page.
Tool A: CdA Reduction
What it does:
If a product claims to save X watts at 50kph, but you want to know how it performs at a different velocity or air density, use this tool to determine its CdA reduction. Once known, you can recalculate watt savings for any velocity or air density. If air density is unknown, assume 1.225kg/m³
Tool B: Watt Savings
What it does:
Enter the CdA and your riding conditions to calculate watt savings. Then use the £/Watt calculator to evaluate the value of your purchase in terms of power saved.
Tool C: £/Watt
What it does:
Use this tool to evaluate how much value (in watts) you're getting for your money. A lower £/Watt ratio indicates better performance per pound spent.
Glossary
- Air Density (kg/m³): The mass of air per unit volume. A typical value is 1.225kg/m³ at sea level.
- Watts (w): A unit of power that measures the effort you're using.
- CdA (m²): Coefficient of drag × frontal area. Lower values = improved aerodynamics.
- Velocity (kph): The speed at which the rider is moving through the air.