How Determine Size Axle Needed for Trailer that is 7 Feet Wide

Published 11/16/2017

Question:

I plan to build a semi-deckover trailer to carry recreational UTVs. I need to know how to decide how I should decide the correct frame width and axle for a trailer that will be 7 ft wide at the outside of the tireshub face w/brakes. I want the spring centers to be as wide as possible and not interfere with tire rotation, etc. I also need to be sure there is clearance from the main frame to the inside of the wheels and tires 15inch 2990 lb. 10 plys for and fender.

asked by: Cecil T

Helpful Expert Reply:

The spring seat dimension will depend on the width of the trailer frame that the leaf springs would mount to. So typically from center of frame channel to center of the other side is the leaf spring seat to seat dimension you'd need for the axle.

So your want the tires to be exactly 7 feet apart measured from outside to outside, that means that you need a trailer axle hub face to face dimension of 76 inches. 15 inch wheel and tires like the part # AM39046 are 8 inches wide. Trailer wheels have a zero offset so that means the tire width divide by two is where the hub face is in the wheel.

expert reply by: Jameson C