[thumbster]

One has to understand that the whole reason the bed bounce is happening is due to the undampened resonance the bed itself creates on the frame. Adding weight is only going to lower the resonant frequency of the vibration. I'm surprised that the tundra is the first vehicle that suffers from this problem - I was followed a late 90s tacoma one day and couldn't miss observing the bed wiggle like crazy as it was driving over a railroad crossing. This tells me that toyota has a very flimzy bed structure design in all of their trucks. In my opinion the only fix for this problem is to stiffen the bed structurally so it doesn't wiggle so much. A spare tire torqued up against the frame is a bandaid approach, but what the heck - if it works then go with it! My tundra doesn't have the problem likely because it's a short bed, but I could imagine that the long beds all would tend to have it depending on the roads in your area.