The Cannondale will be gone pretty quickly. Anything with a brand name and looks nice will be a target. I'd go with a beat up looking single speed or 3 speed of some sort. Make it look ugly. Lots and lots of stickers for easy identification in the rack and to keep it ugly. No quick releases. Put duct tape on the seat to cover non existent tears. A basket helps with carrying stuff and makes it look ugly. Also two seperate and different types of locks that require different techniques to open. U lock and cable is a common way to do it but there are others.