I just made up a fixed wheel from a former freehub with a QR. I'd prefer a conventional axle, but I didn't have any around to swap. It's been on a couple weeks, and it's holding up fine, fully secure. This on an old mtb frame with horizontal dropouts. Tensioning the chain and centering the wheel is a little tricky compared with a bolt on hub. I found the task to be easier if I use an old broom handle as a lever between the tire and bottom bracket/chainstays to tension the tire while closing the QR.