The hard choice

You have a well operating GPS, the old ram-like mount and the motorcycle you own cannot handle this ball mount on its handlebar as it's not long enougn/has no free space on it.
Now comes the choice whether you'll be able to carry your stuff or know how to go to your destination.

Bagster Bag mounts

Bagster had the good idea to put on the Rider bag some spots to attach various stuff (at least you think that at the moment you buy the bag).
In practice, I've never figured out how to attach anything on those bucles and clips in a correct and safe manner.
Then I've beed introduced to 3D printing a few years ago, long after having forgotten this problem.
Those spots can be used in a quite useful manner with some paracord and 3D printed models of your own.

Quick and dirty prototype on Sketchup, 3 hours of printing

And voilà!
SKP file is at bottom of this page. The ball mount is for an old Garmin Nuvi GPS mount.

FYI, RAM mounts have various sizes (see RAM mount sizing on Wikipedia for more info) from 1.428 cm to 8.572 cm diameter.

On the 3D model, the Gopro mount is deteachable on purpose (you'll need some screws and bolts, M3 screws does the trick), so if you break it or whant something else, you can replace only the Gopro mount and don't need to print everything again.

Printing and some tricks

Mine was printed on a Makerbot Replicator 2X in ABS (stronger to heat as it will be in plain sight and sun for 10 hours), with 60 percent infill.
In my opinion, you can print the plate with less infill but I wanted to be sure nothing wrong will happen a 130 kph on the highway.
To avoid scratching the card pouch on my bag, I've cut a rubber strip on the bottom to protect the bag from the plastic and the screws' head. The placement on the bag was the closest to the speedometer with some easy to remove knots in paracord (a bit overkill, yup).

Update (03/01/2017)

Sketchup file : support_GPS_gopro.skp
*Use at your own risk, do not do something stupid and/or illegal with it!.