Offset and Backspacing for Rim and Tire Part # AM30060

Question:

How offset are the 8inch white painted wheels part number AM30060? In other words, on the hub mount side of the wheel, what is the measurement from an imaginary line drawn from inside rim edges to center of wheel where hub bolts on? If I used a 2inch 5 on 4.5 spacer would the wheel fit on a 10inch Dexter Drum Brake hub? I have a very specialized trailer application in mind simply to mount temporary wheels for rolling into my garage. The trailer uses 15inch radials when towed, and I currently have 12inch wheels on it for storage. Unfortunately to clear my garage door I have to let air out of the tires...another 1.5inch of clearance would allow me to do this simply with the wheel change.

asked by: Steve D

Expert Reply:

Trailer rims like the Kenda 4.80/4.00-8 Bias Trailer Tire with 8" White Wheel # AM30060 have a zero offset, meaning the mounting flange is dead center of the rim.

Sounds like you are looking for the backspacing. Since this wheel has a zero offset all you need to do is take the width of the rim (3-3/4 inches), add 1 inch for both wheel lips (4-3/4 inches now), and then divide by 2. Which equals 2-3/8 inches. 2-3/8 inches is the figure you are looking for. Now would using a 2 inch spacer give you enough clearance to mount this tire on a 10 inch brake assembly? That would be really hard to say and not something I could really recommend anyway. Even if it's only to roll the trailer in and out of your storage unit. It might be easier just to find a different storage unit with a taller garage.

expert reply by: Jameson C