It is becoming increasingly difficult to run the free version of BikeCAD using the Java plugin. However, if this is the route you'd like to take, you'll have to follow the instructions at bikecad.ca/java_1.8_security. One new development on that front is that while I used to recommend the ESR version of Firefox for running BikeCAD using the Java plugin, the ESR version of Firefox no longer supports the Java plugin. Therefore, your options are now down to Internet Explorer, or Chrome with the IE tabs extension.
The Scroll down to zoom check box should remain checked for the default scroll wheel effect on zoom, but could be unchecked to reverse the behaviour. There's more info on this at: bikecad.ca/scroll_wheel.
The final thing to note about the Startup tab is the options available in the Paint tab. This is where custom palettes can be created and associated with any of the components of the bicycle design. This section is discussed extensively at: bikecad.ca/configuring_paint_palettes.
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