Swap out your existing rear thru axle for this handy axle from Minoura and you can mount racks, fenders, , etc directly to the center of the axle. It's a great problem solver for frames without eyelets. 

Specs:

• Compatible with 12x142/148 hubs
• Has a mounting eyelet for accessories on both ends of the axle
• Comes with adapters for three different thread pitches: red = 1.0, blue = 1.5, and black = 1.75
• Use to figure out what your axle size and thread pitch are
• 90g / 3.2oz