A servo driven DIY electronic derailleur, now for both front and rear, based on Arduino . The code is now complete, and fully tested on the bench mock-up, and ready for a road test. If you lose your chain and lose track of where you were, a button resets so you can place the chain where it should be, as shown on display, and go from there, or do a complete reset to defaults. Code for Arduino, and construction detail for this project is available at <a href="http://www.excelworks.info" target="_blank">www.excelworks.info</a>