Add led lighting to your bike wheels, program cool patterns, draw images, write messages. If you build the version with the gyro you can even do cool things like make the leds change color according with the tilt of your bike and many other possibilities. All parts were printed with PLA, at 200ºC, with 0.2 layers, 2 outlines, 3 solid top and bottom layers with 15% infill at 60mm/s. If you live in a hot area or will go cycling into to a hot area, you should print these parts in a more heat resisting plastic like ABS or PET. Read the instructions.pdf file for a more detailed guide on how to build. Working example of the simple build: video If you want more complex patterns or cool effects then you need to program those and upload the new code to your arduino. You are ready to go, just toggle the switch and start pedaling. PS Sorry for not showing the project in a bike, mine got stolen some time ago :(