Garmin Varia Saddle Mount

[PaulSB]

My rear light preference is to run a solid day bright light and a Garmin Varia 515 set to flash mode when a vehicle approaches. I'm relatively short, 5' 5", inside leg 29", meaning I don't have much exposed seat post. Fitting two visible lights plus a bag is nigh on impossible. Although I don't ride a Pinarello, this is for my two Cervelos, the image below is precisely how my saddle and bag look - I have the same bag.

I found the saddle rail mount illustrated and wondered if anyone has experience with this or a similar product. Other suggestions would be welcome. I don't like mounting anything on the saddle bag. For the Varia I want to use a solid Garmin mount, no rubber bands. The rear light is a Boost R3, for which I've so far failed to find an alternative to the supplied seat post mounting, this determines where the Boost has to be mounted. There are no M5 fixing points on either of my Cervelos.

 

[geocycle]

I’ve been looking at these recently to see if I can improve on the direct mount to my saddlebag. There seems to be two modes of fixing, one that bolts directly beneath some specific types of saddle and another which will attach to the saddle rails via a clamp. The latter looked to be an option for my Brooks although the clamp is only 7cm long meaning I’d have to mount on the underside of the rails.