Before you put your Mech. Eng. texts and SAE handbooks away, please re-assure the folks that 8" wheels are just fine (for single cat trailers, anyway), and will not "overheat" the bearings at speeds under 100mph. Wheel bearings must meet minimum DOT/SAE/etc. standards, which generally have LOTS of margin built-in. What makes bearings overheat is EXTREME OVERLOADING (or overtightening during installation) and (*ta-DAH*) INSUFFICIENT LUBRICATION, period. Spring loaded hubs, which maintain positive grease pressure, i.e. no air voids, thereby keeping water out, go far in this regard. So does periodic maintenance.

I've had trailers with both size wheels, and in retrospect, I like the 8" better because the boat was lower to the ground, ergo easier to launch, recover, and hop up on to step the mast.

I too worried about the THEORETICAL overspeed of the bearings with my 8" wheels, so once after driving 120 miles non-stop at 70MPH, I pulled over to the shoulder, hopped right out and felt both hubs in quick succession... air temperature. NO problemo...


Of course all of the above applies only to bearings made in the G8 industrial countries. If you buy bearings made in Red China, well, I hope you enjoy the $2.86 savings while your $20,000 A-cat gets a terminal case of road rash.