July 18, 2022

The New RCT715

The new Garmin Varia RCT715 is Garmin's latest radar light introduced in May of 2022.  It features the radar warning found on earlier models, includes a light similar to the previous RTL 510 and 515 models, and also includes a motion activated camera.  This article outlines the challenges behind building a mount for the RCT715 and why we didn't have adapters immediately available for existing mounts.

Mounting Interface

The new RCT715 uses a completely new proprietary interface for mounting the radar light.  It no longer uses the ubiquitous Garmin quarter turn connector.  Instead, the stock mount is intended for a seat post and has a lever activated connection. This is held to the seat post with elastic bands, wire ties, and rubber grommets to fit common seat post shapes. Below is a picture of the RTL515 (bottom) with a standard quarter turn connector, and the new RCT715 (top) and a picture of the rather bulky clamp connector.

RTL515 vs RCT715 RCT715 clamp

Size and Weight

In addition to the mounting interface, the new radar is much bigger and heavier than all previous models (and all GoPro's) that any existing mount was designed to handle.  The RVR315 weighs 50 grams and the RTL515 weights 70 grams.  However, the RTC715 weighs a whopping 217 grams with the stock connector. This light weighs nearly a half a pound!

RVR315 weight RTL515 weight
RTC715 weight
Varia model comparison front Varia model comparison side Varia model comparison back

Stability

Another important feature that is lacking, is image stabilization. As mentioned, the default mount is held on by a rubber band. This allows some flexing from the weight, however this can both cushion and cause jittery video. If the mount is attached directly to a saddle this jitter can be accentuated if not dampened. The mounting point further increases a rotational effect making it very hard to stabilize this camera. If this wasn't a challenge enough, the video is, by today's standard, low resolution 720p or 1080p depending on the frame rate.

RCT715 image shake

Conclusion

The long and short of it comes down to building something that can withstand random constant loading in excess of at least 45-50 lbs (8-10g's) and not violate any legalities with the new Garmin clamp design in the process.  We also have to rethink how to create a safety net in case the clamp or mount let's go for any reason.  Given the weight, we don't imagine this light will bounce very well...

 

Last Update 2022-07-22