Power, Gearing, and % Distribution
US represents United States units. M= Metric units. c= colored versions.
This Spreadsheet is a everyday kind of a calculator. It calculates Power, Gear Inch and % Distribution of power. The calculator is divided into three separate sections in order to reduce confusion of too much data to look at. This allows the user to concentrate on each area. All of the sections are connected through equations.
Before using this spreadsheet
review LAYOUTS.doc to understand the
colors, textures and outline system.
POWER CALCULATOR. There are 14 user inputs and 5 formula cells in the power calculator section. CAUTION; if you accidentally type something in the formula cells you will destroy the formula. To protect yourself, make a backup copy before using the calculators.
You may click on the formula cells and the formula will appear in the formula tool bar which is a informative thing to do. Then move off the cell and click on the background. The Power cell contains a long formula. The formulation was derived by Joel Sanders from first principles of mechanics and can be read in “PRIMER ON BICYCLE MECHANICS”, which can be obtained as a monograph from the HPVA.
GEAR CHART: User inputs are Chain ring teeth, Hub gear teeth and Wheel diameter. The two middle cells are for an Intermediate drive. Without a Intermediate drive insert 1 in the In cell and 1 in the Out cell. Otherwise plug in the number of teeth for the Input cog and the Output cog. Cadence and wheel rpm changes as speed is changed.
% DISTRIBUTION CHART: Gives a breakdown of power and % distribution of that power. As you change the user inputs in the Power calculator section the distribution of power are automatically calculated. Do not type anything in any of the distribution chart cells.
To estimate CdA and Crr see Repchrt,jpg
Measuring you power capability see PwrCap.doc
For human power capability see HPcapTxt.doc
Acceleration and wheel weight