Is there anywhere that I can buy a d shaped post mount for my second bike. I have the RTL515 which comes with the d shaped post mount but the Garmin mount that is for sale for the varia doesn’t seem to come with the D shaped post mount. Any ideas?
Is there anywhere that I can buy a d shaped post mount for my second bike. I have the RTL515 which comes with the d shaped post mount but the Garmin mount that is for sale for the varia doesn’t seem to come with the D shaped post mount. Any ideas?
Hello, I used standard kit for mounting on the round shape seat post on the D profile and so far no problem... (140km so far)
Varia
Universal Seat-post Quarter Turn Mount
https://buy.garmin.com/en-US/US/p/521431/pn/010-10644-12
You have to buy the whole mounting kit but it does come with the "D" shaped shim. Works great on my…
I would say it's more stable than on the round one. But if you find some nice on for the D shape let me know.
Based on your pics we have the same bike (GO BMC). Have you not used the insert attachment that sits between the mount and seat post? My RTL515 came with various inserts and there is one that fits perfect on D shaped posts. 
I have the Teammachine SLR02 one and previous model RTL 510 
The insert is for round and aero seat post only in this version, but so far it's OK.