A.
anwered by: canteau
To convert the El Mariachi to thru-axle, you will need this plate along with the right-hand plate that has M12x1.75 threading and a 12x174mm thru-axle with 1.75 thread pitch and 20mm of thread.
If you are doing a geared setup, the matching right Salsa Alternator Plate can be found by searching for part # FS1373 and the Axle is Salsa part # FS8110