I use PVC pipe in lieu of beach wheels for my beachcats. They work very well and it doesn't seem to matter if they roll or not. I don't notice any real difference whether the pipe rolls along as the boat moves, or if they catch on a rock and the boat slides over the top of the pipe(s)

I've found it convenient to carry a 2" nested inside a 3" piece of PVC pipe, held in there by simply installing a PVC cap on each end of the 3". This way, I'm only having to deal with one pipe while sailing and then open it and I have easy access to the other piece of PVC.

My pipes are 9 footers and I lash them under the tramp right next to one of my hulls. They seem to ride there pretty well and are out of the way, don't catch water and are easy to get to when I want to use them to roll the boat up onto the beach.

The only alteration I'm thinking of making, is to glue or somehow affix a permenant strap to the pipe to aid in lashing the system to the underside of my tramp. In a pounding sea, I've noticed my system seems to creep aft, sliding through my existing lashing. I think affixing the lashing permenantly to the pipe would stop that.

Good luck.