Designing my own Garmin Varia mount

mmendoza87 · #1 08-20-2020, 12:24 AM

I've been running the Varia RVR315 for a few months now. Besides my Wahoo Elemnt Bolt, water bottles, and frame/handlebar/saddle bag, I won't go on a ride without the Varia. It's nice to have a little more awareness of the cars behind you. And it was one of those things I didn't feel I needed until I used it.

There's one thing that bugs me, the bulky, heavy, fiddly mount for the Varia. While it was designed to fit a variety of seatpost shapes thanks to its changable rubber spacers, it's clumsily overbuilt and the rubber bands don't do a good job keeping it positioned. I often take the whole mount off when I take bike photos.

There are options of mounting it under the saddle or clipping it onto a bag, but I didn't like those solutions either. I went off to design and 3d print my own custom Varia mount. I started by tracing the cross section of my Roadmachine seatpost which I then scanned and translated it to CAD:

Luckily i'm very handy with CAD surfacing and have designed many plastic/metal parts in the past:

It's a simple part that uses the included Garmin 1/4 turn interface (that is screwed onto the mount). A brass insert and M4 screw from Mcmaster to clamp it to the seatpost.

I also made a version that has a standard 27.2mm round cross section (right)

I gave the Varia unit a 3 degree upwards angle which you can kind of see in the side view.

As for printing: I sent it off to Shapeways. I went with "Versatile Plastic" which I have used before as a material to order a Blendr mount for my Wahoo to use on the BMC stem. It's fairly strong and holds up well under heat, with some flex to give if it gets knocked.

Total price (after Black color surcharge and service fees) comes out to about $19/pc.

It should be in next week. I'll report how it works and most importantly how much better it looks!

rlanger · #2 08-20-2020, 04:30 AM

Nice work. Looking forward to seeing the finished product on your bike.

Clancy · #3 08-20-2020, 05:58 AM

I am both impressed at your skills as well as jealous of them.

Will there be an opportunity to purchase one? I picked up a Varia awhile back and like you I won’t go on a ride w/o it. And like you I’ve found the stock mount lacking. Yours is very well designed.

jb_11 · #4 08-20-2020, 06:58 AM

Nice work.

I just use Garmin's version of the same on my D shaped post:
https://buy.garmin.com/en-US/US/p/521461

There's obviously a slight gap at the rear, but I can live with it.

mmendoza87 · #5 08-20-2020, 03:00 PM

Quote:

Originally Posted by jb_11

Nice work.

I just use Garmin's version of the same on my D shaped post:
https://buy.garmin.com/en-US/US/p/521461

There's obviously a slight gap at the rear, but I can live with it.

Slightly better than the stock mount, though the two clamping bolts on either side of the seatpost look quite bulky!

djg21 · #6 05-24-2021, 12:12 PM

Quote:

Originally Posted by jb_11

Nice work.

I just use Garmin's version of the same on my D shaped post:
https://buy.garmin.com/en-US/US/p/521461

There's obviously a slight gap at the rear, but I can live with it.

This is what I use too.

iPaul · #7 05-24-2021, 04:04 PM

I use that one as well. Issue is my not so massive thighs still clip the "ears" when I ride. Love the one that mmendoza87 designed. Love to print it myself using something fancy if he would be willing to share the file.

mmendoza87 · #8 05-26-2021, 10:11 PM

Hey all,

I switched to a bike that uses a round 27.2mm seatpost, so I ended up redesigning the mount from the original post, greatly simplifying and lightening it (also making it cheaper to print). I made 2 versions: one specific to the Allied Alfa which has a horizontal frame cut-off at the seatpost and one that has a perpendicular cutoff (like what a standard seat post collar would result in.) It uses a grub screw (Mcmaster #92605A100) instead of a nut and M3 screw, like my previous design. The grub screw pushes against a "flap" printed inside the mount which then presses against the seatpost. To prevent any scratching, you just need a piece of tape between the mount and the seatpost. It holds pretty well and looks super slim.

The final weight is just 7g with grub screw.

iPaul · #9 05-27-2021, 04:30 AM

This is great and that’s the same frame I’m looking to match up with. Really like how integrated you designed this.

Would it be possible to point me in the direction on how I can get one or better yet post a link to the stl file that would be great.

cgolvin · #10 06-08-2021, 11:04 AM

I too would be interested in purchasing one of these (for standard round 27.2 post). If you've posted it to Shapeways, can you provide the link? And if not, perhaps you can share the design so that we could order one?

Even better, maybe -- if there's sufficient volume from forum members maybe someone could arrange a bulk purchase including the McMaster piece? I have no experience dealing with 3D print designs or Shapeways so I'm reluctant to volunteer, but happy to assist.