Will Changing Tire Size Reduce A Vibration Occurring On a Wave Runner Trailer Between 65 & 70 MPH?

Question:

I have a single 2020 Continental PWC/Waverunner trailer. It has 12” radial tiresrated for 81mph on steel wheels. I get some vibration when I hit 65mph but it seems to go away when I hit around 70mph. New hubs/bearings installed, castle nut hand tightened. Tires balanced with a 1.50 weight on both tires. If there is room, would a 14” tire/wheel combination provide a better ride or am I just dreaming and maybe it’s something else?

asked by: Barry B

Expert Reply:

Being as the vibration begins around 65mph and goes away at 70mph it sounds like it is some type of harmonic vibration. With the larger diameter of a ST205/75R14 Radial Trailer Tire with 14" Black Mod Wheel # AM32131 this would change the amount of revolutions the hub is spinning and may do away with your vibration. As the vibration goes away when you go faster it can be very difficult to find the exact cause. To give you an idea of the difference at 65mph with the 14" tire this would turn the same amount of revolutions as a 4.8-12 at 82mph.

expert reply by: Bud M