The file 'GoPro Mount For Bicycle Seat Post 25.4mm, 27.2mm & 31.6mm 3D Printer Model' is (stl) file type, size is 110.1KB.
This is a simple gopro mount for round seatposts that are 27.2mm and 31.6mm. After you print the left and right pieces of the one you need, use an electrical tape on the inside parts that goes round the seat post to ensure a tight fit.
To secure the mount, you need to use 2x M4x20mm (M4x16mm might also work) bolts and 2x M4 standard hex nuts.
Then use M5 bolts and nuts for the GoPro connection to the camera or the optional extender.
Note the extender is optional if you want the camera further back or have an awkward angle.
Edit. Added a 25.4mm version for my cannondale synapse
J_GoProExtenderStraight_V2.stl | 78.8KB | |
J_SeatPost27_2MountLeft.stl | 112.0KB | |
J_SeatPost27_2MountRight.stl | 74.3KB | |
J_SeatPost31x6MountLeft.stl | 100.7KB | |
J_SeatPost31x6MountRight.stl | 96.2KB | |
SeatPost25.4MountLeft.stl | 118.2KB | |
SeatPost25.4MountRight.stl | 64.1KB |