If, like me, you’ve tried using bike radar, you might find that you don’t want to ride without it. But if, like me, you get a new bike or modify your existing bike so that you find that you can no longer readily use your radar unit on your seatpost, what do you do? This post is about a couple of creative ways I’ve used for installing Garmin Varia RCT715 when I could not install it on my seatpost.
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The Garmin Varia radar units come equipped with bands for installation on your seatpost. But what if, for instance, you decide to install a dropper post? And what if, perhaps, you also like to carry stuff on top of a rear bike rack that obscures your Varia unit?
If you’re interested in this post, you might also want to check out our posts on whether you need bike radar and our review of the Garmin Varia RCT715.
The instructions for these units also specify a minimum height from the ground to be effective and also need to be installed straight-on, rather than at an angle.
There are, of course, workarounds for these obstacles, and it took some time to figure out what would work for my bikes.
Mounting options for Garmin Varia bike radar units
The Garmin RTL515 unit — the one without the additional video camera — uses the same quarter-turn mount as the Garmin Edge cycling computers and is, additionally, a much lighter weight device. As such, there are quite a few alternate mounting options including saddlebag clip-on mounts and saddle mounts.
However, I went all-out and got the Garmin RCT715. This is a larger, heavier unit because it includes a video camera 1. And it uses a different mount than the smaller units.
The issues
My e-bike was the first to get the Varia. But there were issues.
If I used my Po Campo Vernon trunk bag, which I love, the unit would be obscured. And with the dropper post and the size of my rack, anyway, it didn’t work. If I strapped the unit on at the bottom of my dropper post, the rack obscured it, at least partially. And I couldn’t connect it to the stanchion of my dropper post for obvious reasons. I use a Brooks saddle. Connecting the unit to the saddle also didn’t work well and was still obscured if I use the trunk bag.
In the photo above, you can see that if the bag were fully loaded it would block a Varia in any seatpost or saddle mount. Mounting a Varia on the stanchion just wouldn’t work, and there’s no room to mount it below that as it’s blocked by the ebike battery.
Note that I DID try out the Varia on another bike with no rack by mounting it with the straps around the dropper post collar, and that did work. What you can’t see in this photo is that, in the back, the ebike has a wired rear light taking up the 50mm tail light bolt holes on the rack. As I don’t want to disconnect that, installing there wasn’t an option.
So what to do? It took some creativity.
Let’s look at what my solution was for installing my RCT715, as well as some alternate connectors for the other Garmin Varia units.
What the Garmin RCT715 comes with out of the box
Out of the box, the Garmin Varia RCT715 only comes with some collars to be able to attach it to a seatpost and some silicone straps to hook those on (The photo below includes a plate I detatched so I could install it using the method below, as well.)
Alternate connectors for the Garmin RCT715
When it comes to finding alternate connectors for installing Garmin Varia RCT715, the choices on Amazon are limited. You’ll find that they have a seatpost mount and a saddle mount.
The best solutions I could find for being able to tweak installation of the unit were from BUP Labs.
They make a variety of mounts, including some for installing Garmin Varia RCT715. These, combined with some GoPro mounts and arms, finally did the trick. I had experimented with 3D printing some RCT715 adapters. However, I found they were too weak for my comfort if printed with PLA. It wasn’t worth it to try printing with a new material when I could buy a mount from BUP.
Be careful when you’re ordering a mount from BUP. In most cases, you’ll need to get two pieces: the mounting base and the mount arm. However, with my ebike, I ended up not using their mounting baseplate. For my purposes, I just needed the Garmin RCT715 mounting arm so that it would connect with GoPro connectors.
If you have an available light mount on your rack, you can just get a GoPro-compatible rack light mount plate. BUP has one available on their website. Then, you have to get the mount arm specific to the RCT715. This part has the hole at the top to connect it to a Garmin mount. You then unscrew the default seatpost attachment from the plate that came with the Garmin and then attach it to the one you received from BUP Labs. You can kind of see this in the photos below.
But I had an issue: my light plate was taken up. Any place I tried to install the Varia was blocked or would end up being at an angle, or too low.
My Solutions to Installing Garmin Varia RCT715 on my bikes
Installing Garmin Varia RCT715 on my ebike
With my e-bike, what I finally did was this: get creative.
My bike rack is hefty and I found that the GoPro bike handlebar/post-seatpost mount with the smallest rubber shim would clamp on to the back of my rear rack.
Mounting the BUP Labs mounting arm directly via a Gopro connector and short arm would have resulted in it not being place correctly, so I used some HSU GoPro arms and adapters to lengthen the placement and put the Varia device into a straight-on position. This has held up quite well, and has stayed in place during rides and even in carrying the bike on the back of my vehicle (though I always remove the Varia before transporting the bike).
Installing Garmin Varia RCT715 on my gravel bike
At some point I wanted to go “analog.” Soon I was down the rabbit hole of building a bike from parts. However, I’d grown attached to traffic input from the Varia RCT715. I wanted to also use it on my new bike. In many ways, my new me-powered bike is set up like my ebike. It sports a Brooks saddle, dropper post, and rear rack. But my new rack also does not have an available spot to add the mount.
However, do not believe that I will be carrying a bag atop this bike rack unless it’s camping gear. In that case, I’ll be mostly off-road where the point of a radar device becomes moot. So, that opened up the possibilities for installing the unit closer to the saddle.
Because this bike also has a dropper post, a seatpost mount option was out of the picture. And, again, I have a rack, so mounting it at the bottom near the dropper post collar was out. The rack would, as well, obscure it. Additionally, the dropper post I am using is a RockShox Reverb AXS XPLR . Its battery compartment takes up quite a bit of space under the saddle. Between that and the width on the outer part of the Brooks B-17 carved short saddle rails, I could not use any of the available saddle mounts I could find. And, no, I’m not giving up my Brooks saddle!
Fortunately, Brooks saddles have those two little loops. And zip ties exist.
I used a bike rack light mount and zip tied it to the loops on the saddle.
Yes, it dangles a bit but, so far, it’s worked fine and the zip ties have held it securely.
Here’s a view of the BUP mounting arm for the RCT715 from the back:
Summary
If you’re struggling with installing Garmin Varia RCT715 because, like me, you like weird bike setups, don’t give up! Get creative and you’ll find somewhere to place it.
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Footnotes
- I suppose in case someone kills you at least there maybe was a video of the accident. Very reassuring.[↩]
