One thing that stood out to me when I wrote about Garmin’s Varia rear radar was how much the appearance – and perhaps even the function - of the radar technology varied between head unit brands and models. Even between the varying types of units produced by a single brand.

Garmin makes the Varia rear radar, and it makes GPS head units that intake the Varia’s signal and displays the cars as they approach. But it also allows the makers of other head units to pair with the Varia. I shot a 30-second video that shows you what several displays look like when synced to the same Varia.

Note the differences. Colored bands. Dots (Garmin) versus little car icons (Wahoo). Garmin shows you as either a dot or a chevron; Wahoo doesn't. LEDs (Wahoo) versus no LEDs (Garmin). On the Garmin your choice of left or right hand column display. You'll probably want to full-screen the video to see the details.

Before you watch this, here some of my caveats and disclosures…

It can be pretty challenging coaxing cooperation out of a bunch of head units in close proximity to each other. ANT+ signals appear to behave in unanticipated ways when they bounce off each other, and one brand of head unit in particular had a habit of shutting itself off spontaneously under this duress. As a result, the layout of the head units was very much an exercise in “everything is working, press record NOW!” Some elements of layout symmetry and aesthetics definitely suffered as a result.

The camera used for this was a GoPro with natural lighting, and with natural lighting it’s really hard to get seven different reflective surfaces all in alignment. As you will see on the video, there is one head unit in particular that has a prominent stripe of glare directly over the portion of the screen devoted to the Varia display. I was going to re-shoot this in an effort to remove the glare, but upon (hah!) reflection, realized that I had actually experienced this effect in real-life usage, so why not just display it here as well. In other words, I’ve decided the glare in my video is a feature not a bug.

All my head units are equally prone to occasional glare. Manufacturers consider this in product design. With the Wahoo seen in the video, the flashing LED lights provide ample evidence that there is traffic about, even though the display is obscured. With the larger Garmin units, the “red band” alert on both sides of the screen serves a similar function. The absence of such redundancy on the smaller displays - as seen in the video - may inform your purchase decision if Varia functionality is a priority!

I’ll post more video soon, isolated to just a couple of head units. Better (artificial!) lighting, close-up views, other manufacturers. Stay tuned…

Here’s the list of head units on display:

Far left: Garmin Forerunner 945
Top row: L-R – Wahoo ELEMNT, Garmin Edge 130, Wahoo ELEMNT ROAM.
Bottom row: L-R – Wahoo ELEMNT Bolt, Garmin Edge 1030, Garmin Edge 830