I'm working on mounting the Kepler friction drive to my 2008 Giant Reign. If it works as well as I hope, I will probably install it on my 2013 Trance 29er. I suspect that quite a few Giants with Maestro suspension are similar.
Reign - Looks like Giant provided some holes in the swingarm.
Enlarged the holes a bit and installed some M6 threaded inserts - McMaster Carr PN 91230A009.
Bracket from 1/4" thick Angle Aluminum. Unfortunately the mounting area is not flat, so I needed to contour the bracket, and the holes will be angled.
Need to drill & tap some holes. I will probably add a brace near the front, as I'm not sure the two inserts are adequate on their own - TBD.
I will probably use my 6354 140KV motor. This is the 5045, which may or may not be underpowered. TBD.
Trance 29er. I like the large, flat mounting area (where the 2 zip ties are). The plan would be to drill and tap three M5 holes in the flat area.