As they come, the straps with the captive nut are too short to reach the end of the machine screw without being at an angle. The threads *might* catch the nut, but then will try to cross-thread. I ended up cutting off the "captive" part that holds the nut with a carpet knife and ******** the strap on with no nut for a bit. There's enough of an edge on the hole through the plastic to catch a groove between threads. A few turns to cinch the strap down so a bit of the end of the screw is showing, then the nut could be threaded on properly and ******* down tight. This only worked because I was able to get a little (8mm?) spanner through to hold the nut while tightening the screw. If I hadn't had clearance, I could have taken the rack off the bike to mount the adapters without the wheel (and fender) in the way.