BikeCAD
A fully featured Java applet that allows you to design your own bike.
Here’s one monstrosity of a Farthing-Penny I knocked up earlier, giving you a pedestrian 9381.9 gear-inches, meaning that for a leisurely cadence of 60 rpm you’d be travelling at a sauntering 2120.6 kph (just under Mach 2) - if you’re superman on steroids.
