I've discovered something that appears to be ten times harder to accomplish than it should be.

As a touring motorcyclist who likes to get out for a blast in the weekends from time to time, I like to find new and interesting routes by looking on Google Earth or various other online maps.

What I'd really like to do is make up a route entirely arbitrarily on my computer screen (definitely not just based on "A to B" directions!) and transfer that to my Android phone (currently an S3 but soon to be an S6) which is connected to the bluetooth headset in my helmet.

From there I want my phone to give me directions according to the route I'd planned on my PC and transferred to it.

Take a look at geodistance.com - this allows you to trace out an entirely arbitrary route (if you click "snap to roads") but you can't then save the resultant trace or use it in any way.

The missing link is to then be able to transfer this to a phone which has GPS so can then give directions on the road.

Garmin have an app that seems able to do this but you need a Garmin GPS unit to make it work. I don't want to buy another device to be able to do what I inherently feel my android phone should be able to do by itself. 

You can kind-of do this in Google Maps, but it's based on the "driving directions" for an A to B route - making it impossible to plan out a few deviations on the way, or to map up a round trip.

Surely this must be easily possible and I'm just being galactically stupid?? Anyone got any experience in this area??