Do Trailer Hubs have a Speed Rating for Use on a Boat Trailer and Highway

Question:

Am looking to buy new hubs for my boat trailer, With todays highway speeds how do I know which hub will hold up under high speed, 70+ mph, and high heat?

asked by: Greg K

Expert Reply:

The issue that you are going to run into is that trailer tires are not rated for 70 miles per hour or more. The tires we carry are rated for a maximum of 65 miles per hour. The hubs would be limited to that. Some agricultural hubs are only rated for 20 miles per hour but on a boat trailer I am almost certain it does not have agricultural hubs.

To get some new hubs I will need to know the inner and outer bearing numbers stamped into the bearings. With those numbers along with the bolt pattern of the wheels I can make some recommendations.

Getting back to the tires the reason trailer tires are rated lower is because they are constructed differently than passenger vehicle tires. Trailer tires have a thicker side wall to handle more vertical load. This thicker side wall can generate more heat than a regular tire and heat is the number one enemy of the tire.

The thicker side wall is also why trailer tires should always be inflated to the maximum psi indicated on the tire. If under inflated it will cause that thicker side wall to generate excessive heat and lead to tire failure.

Do not feel like you have to go 70 miles per hour just because that is the speed limit. It is much better to be safe and dropping down to 65 miles per hour is not much of a decrease and could be the difference between a fun weekend out on the water or a blowout or worse.

I have included some links to the right on trailer tires and bolt pattern. Once you have those bearing numbers I can recommend some hubs.

expert reply by: Michael H