I installed these on my 2002 Dodge Ram with a sprayed in bedliner. The clamps held tight for over 1000 miles. The rest of the bed of the truck bed was free to haul other equipment. They are also compact for storage in the off season.
I needed a mount that was easy to set up and compact for storage on the off season. The bikes rode up next to the cab so they were protected from the wind. I was also able to preserve 80% of my bedspace for other equipment. I highly recommend these clamps.