This page has motorcycle setup sheets and free downloads that are useful for keeping track of your chassis setup and give you some direction on making changes. The setup sheets are in pdf and Excel format, while the gearing chart, rake/trail calculator and thrust chart are all in Excel format.

## Gearing Chart

Gearing is one of the most basic and important setup variables for on-track performance. Using this chart, you can input all the details about your bike’s gearbox – primary, secondary and internal ratios – and see how that changes maximum speed in each gear for a range of front and rear sprockets. The chart also calculates an approximate swingarm length for a given chain length; using that information, you see how much your wheelbase will change and if you have room to adjust your wheel to the required chain tension, all before you make the actual change. Download the gearing chart in Excel format: gearing_chart_v1-3.xls

## Rake/Trail Calculator

Trail is an important dimension in motorcycle chassis design as that value has a large effect on how the motorcycle will handle. This page includes HTML and Excel versions of a rake and trail calculator; both calculate trail based on input values for rake, offset and front tire radius. More information and both versions of the calculator are here: Motorcycle Rake and Trail Calculator.

## Thrust Chart

Thrust is a measure of actual driving force delivered to the motorcycle’s rear wheel, and is calculated as torque multiplied through the primary ratio, internal transmission ratios, secondary ratio, and over the radius of the rear tire. This chart produces a thrust chart for each gear, and calculates the optimum shift points to maximize thrust at any given speed. The chart allows you to see how changing the internal gear ratios affect thrust and shift points, and how changing the engine’s power delivery characteristics changes performance. Download the thrust chart in Excel format: thrust_chart_v1-2.xls

Suspension Histogram Analysis

One very useful technique for suspension setup is to use histograms and suspension velocity analysis to evaluate spring and damping settings. Histograms put values to how much time the suspension is active in each damping range (high-speed and low-speed compression and rebound damping), and by using some basic statistical analysis techniques, that information can be used to make spring and/or damping adjustments to the motorcycle and improve its performance. This Excel file takes suspension velocity data, plots the required histograms and outputs a summary of the time spent in each damping zone. More details on analyzing the histograms are here: http://www.datamc.org/2016/04/12/histograms-suspension-velocity-analysis/

Anti-Squat Calculator

The anti-squat calculator shows results for two geometry setups, displaying a graph of anti-squat percentage or angle vs. wheel travel, and a line diagram of the motorcycle’s layout with the relevant force lines for each setup. The calculator also outputs a polynomial equation for anti-squat that can be used as a math channel in a data acquisition software package. More information and the download file is here: Motorcycle Anti-Squat Calculator

Spring Rate Conversion

Use this html spring rate conversion calculator to convert between units of kg/mm, N/mm and lb./in. for motorcycle spring rates. Input a value in the first field, select “from” and “to” units in the second, and the new value will be output. Motorcycle Spring Rate Conversion