What Could Cause Boat Trailer Tires to Wear More on Inside Tread of Both Left and Right Tires

Question:

tires wearing on the inside tread of both left and right side

asked by: Jose

Expert Reply:

The most common cause for trailer tires' tread to wear more on their inside edge than their outside edge is overloading of the trailer. If a trailer axle is overloaded it's center will bend down toward the road surface and this will change its geometry, causing the inside edges of the tires to make more contact with the road surface than the outside edges. This will lead to uneven tread wear with more wear on the insides.

Please see the linked diagram.

An axle in good condition that is not overloaded will keep the tires' surfaces evenly placed on the road and this will result in even tread wear as long as the tires are properly inflated. Only special trailer type tires (ST type) should be used on a trailer and they should always be inflated to the maximum psi pressure rating shown on the tire sidewall.

An under-inflated tire will tend to wear at both outside edges while an over-inflated tire will tend to wear more at the center of the tread.

expert reply by: Adam R