Varia mounting options

Here's a very simple option if you want to mount your Varia RTL510 to the luggage loop on your saddlebag.

Mounting the unit to the seat post is not an option for me because my seat post is completely covered by my saddlebag.  I've considered mounting it to the rear fork, but that would result in the unit being angled sharply upward, and might affect how far away it can be seen.

Easy solution.  Go online and search for commonly available "metal belt clips" typically used for gun holsters and knife sheaths, and look for one that has a width dimension compatible with the width dimension of the luggage loop on your saddle bag.

Here's the one I ordered due to the fast delivery time:  https://www.amazon.com/Holster-Sheath-Carbon-Powder-Coated/dp/B06XTCQ1DW/ref=sr_1_9?keywords=metal+belt+clip&qid=1565102457&s=gateway&sr=8-9

Another example:  https://www.knifekits.com/vcom/belt-clip-universal-sheathholster-model-black-tactical-finish-p-1486.html

Now, go down to your local the hardware store, Home Depot or whatever is local to you, and buy some industrial strength hook and loop (velcro) material with adhesive backing. The industrial grade velcro at Home Depot has a 15-lb rating.  The type I use is the plastic variety that is typically used for attaching toll transponders to your car windshield.  Either is more than enough for the RTL 510, and some margin left over for those nasty bumps and potholes you didn't see coming.

Using scissors, trim the velcro to match the belt clip and the back of your RTL510 varia, but don't cover the quad-lock mount, just in case you ever want to use it.  No artistic talent required.

This is a very strong and secure option, much stronger than the Garmin-supplied rubber band mount, and less expensive than spending $25 USD plus shipping on a less-than-robust piece of plastic from Shapeways (you've got to be kidding me!).

A picture of the final result, with a short piece of velcro strap wrapped around the unit for added security: https://imgur.com/VSpFsWS

I will close with one more easy option, for those who don't want to spend the money on a store bought belt clip.  All you really need is a thin piece of metal, a tin can, or a cheap downspout strap (less than $1.50 US).  While I was waiting for my store bought clip to be delivered in the mail, I improvised a clip using a common downspout strap.  Light weight enough to work with your hands, but plenty strong to support a Varia.  I used a pair of sheet metal shears to cut the strap into a strip about 7/8-inch x 8 inches.  Then folded it in half so now it's about 4-inches long. I also drilled a 1/4-inch hole through both ends at the bottom so I could put a zip tie through it so there's no way it could bounce off.  I mounted both my Varia and a Bontrager Flare R, using industrial strength velcro for the Varia, and the Bontrager belt clip for the Flare R.  They aren't going anywhere, but for added security you could always wrap a velcro strap around the Varia. Worked like a champ on my first ride with it this morning.