A Tire Question

[Lester]

We haven't used our 28' 5th wheel since 2004 so I'm looking at new tires.
Since it has 225/75R 15 tires now with an OD of 28.3" could I replace them with 235/85R 16 OD of 31.5" and should I ? The distance between the front and rear tires is 5". I'm thinking, the same RPM as the tow vehicle. Thank you for your experience.
Matt

[JIMNLIN]

My used 28' 5er with two slides came with brand new ST225/75-15 D. I don't use ST tires on any trailer so a trip to my truck tire dealer was required.
The LT235/75-16 E was too tall to fit under my trailers wheel wells. I had to go with the LT215/85-16 E.

You have plenty of distance between the tires but how about clearance at the top and sides of the tire.

The trailers tire rpm vs the trucks tires rpm being equal has no advantage or disadvantage.

[Lester]

Thank YOU for the reply jimnlin.
Matt

[wa8yxm]

Well.. if the shoe fits go ahead and wear it..

In this case get out the old ruler and make sure there is enough room in the wheel well for the wheels, make sure you'll be able to get 'em in and out and that they will be far enough apart if it has dual axles..

Consider that the trailer will "Bottom out" on its suspension when you take those measurements.

[rgreen45]

Quote:

Originally Posted by wa8yxm Consider that the trailer will "Bottom out" on its suspension when you take those measurements.

Excellent point!

There's no advantage to changing tire size. Changing tire quality however could be a plus. The bulk of the tire damage I see (I'm an RV tech) is caused by either under inflated tires letting go or old, dry-rotted tires failing.

[FastEagle]

Quote:

Originally Posted by Lester We haven't used our 28' 5th wheel since 2004 so I'm looking at new tires. Since it has 225/75R 15 tires now with an OD of 28.3" could I replace them with 235/85R 16 OD of 31.5" and should I ? The distance between the front and rear tires is 5". I'm thinking, the same RPM as the tow vehicle. Thank you for your experience. Matt

Since you didn't give us a load range for the tires you're replacing I'll make one up for the math. The ST225/75R15D has a Load capacity of 2540#. With that in mind the LT225/75R16E with a load capacity of 2680# might just be the best replacement size for you. It's diameter - 29.4" - is closer than the larger tire you mentioned and it has a nicer load capacity than the ST if I've struck on the right size..

FastEagle