Wha-What??
Really simple design of Trek Superfly SS.
16mm nut on both ends holds slider plate once adjusted, threaded set screw(behind stays) on both ends moves slider plate. Thru axle threads into interior of 16mm nut.
Hopefully this will last.
View attachment 35072
It's lasted for me since January...no issues. Love this bike.
Much betterer than the '13 Trek RIG design that was always giving me trouble and eventually snapped at the lower slider.