What is Minimum Distance Require between Tandem Trailer Tires When Considering Increasing Tire Size

Published 05/03/2016

Question:

Hello I have a Dual axel trailer with 6 lug 225 75 15 wheels. If I want to move up to a 6 lug 235 80 16 wheels, will I have to move my axels further apart? They are spaced 33inch apart now. Would that weaken the frame?

asked by: John

Expert Reply:

The difference in tire diameter will be an additional 2-1/2 inches going from the 225/75-15 which measure 28.4 to the 235/80-16 which measure 30.9 inches.

As a general rule of thumb the minimum safe distance between front and rear tires on the same side of a tandem axle trailer is 4 inches. You would need to measure the distance between your tires currently and subtract 2-1/2 inches. If that dimension then ends up being 4 inches or greater the axle placement could be left alone.

Looking at the picture you submitted it looks too close to call from here.

Moving the axles would not necessarily weaken the frame. You would most likely have to move the outside most hangers out further and then use a long equalizer. You might run into fender clearance issues as well so this could end up being quite an ordeal.

expert reply by: Jameson C