Custom Bike rack for truck.

We used to have a 2x4 with fork mounts bolted to it in my Chevy Silverado 2500K. The truck bed has molded areas where you can slip the 2x4 in and the board won't move (the molded areas are really there so you can place three 2x4's across the bed of the truck so it forms a platform above the bead for hauling bigger stuff.) Anyway, it wasn't lockable, but did work great for just transporting the bikes. If we had needed to lock them, we could have put a cable lock around them bikes and locked them to the gooseneck trailer hitch safety chain loops. Which I kind of doubt you have in a Ridgeline...   But I just wanted to let you know that it does work well as a way to transport them (helps if you have an extended or crew cab so you can put the front wheels in the back seat.)

I have a Nissan Frontier with the short bed. I use a fork drilled into a 2x4. I also put two cinder blocks on each side just to make sure it doesn't tip over. Works great for me. Depending where I go I'll lock the bike onto the bed extender cage.