VeloNews Road Road Racing Ask a Mechanic: Details on Shimano’s D-Fly Are you using all of your Shimano Di2 system's features? Art's Cyclery explains the wireless D-Fly features. Facebook Icon Twitter Icon Email Icon Art's Cyclery explains Shimano D-Fly in the latest Ask a Mechanic video. Heading out the door? Read this article on the new Outside+ app available now on iOS devices for members! Download the app.