In addition to downloading the RidewithGPS files directly to his smartphone, (see RidewithGPS Maps Offline on Your Smart Phone) my friend and fellow coast to coast rider, Bruce, also exports the Garmin files directly to the external storage on his phone. This can be done from the RidewithGPS website using a web browser and the site’s export function. It should be noted however, that this can’t be done from the RidewithGPS app. It can only be done from the smartphone web browser. With the RidewithGPS route files on your smartphone they then can be sent to Garmin devices without using a computer.
To do this you need a dongle that allows a direct connection between the smartphone and the Garmin device. In my case, for example, I have a Samsung Galaxy S8+ smart phone with a USB-C port and a Garmin Edge 1030 with a micro-USB port. Therefore, I need a male USB-C to male micro-USB cable to attach my smartphone to the Garmin. A USB Type-C to Micro-B 2.0 Cable can be found on Amazon and elsewhere.
Once the two devices are attached, my smartphone sees my Garmin as an external storage device and I simply copy the file to my Garmin device using the path Garmin > NewFiles on the micro SD card in my Garmin device as illustrated below.
Hopefully, RidewithGPS will add the ability to export Garmin files directly to the smartphone external storage in their next app update.