That's what I had as a kid.
2" schedule 20 PVC with a slot in the bottom of the tube for the reel seat. Mounted with two hose clamps. Whole thing less than 10 bucks and you can cut it with a serrated knife. We then cut off a 2"pc of the slotted end of the tube and that could be snapped over the main tube behind the reel seat, covering the slot to hold everything in the tube. Rod tip sticks out the back. Breaking the rod down into two pc less than 5' each would be best.
For a time when I lived near the beach, I did this with a 10ft 3" PVC for a surf rod, clamped onto a beach cruser. The surf rod was a 1pc custom and it was so long that it needed to be protected. More than once the tip was broken off by a sharp turn or someone coming up from behind who didn't see it.
Paint some flames on that sucker and you're all set...a fishing rod holder is much cooler than a baseball card in the spokes.
