Tires and axle

Probably your best answer will come from your trailer's axle manufacturer. Dexter says the minimum distance is 1".

Item #24 in this reference.

I have had 2 blowouts on same left rear tire. Within 200 miles of each other. Of course they are China bombs "as folks call them ". I'm putting on 4 Michelin LT 245/75R16 E XPS Ribs tomorrow. Plus the 507 tst tpms. Hope this takes care of it.

Moved from technology

How big are the road stones where you might travel?

I read the clearance between tires should be 1" minimum.
What is the concern in your situation?

There is and it may vary from brand of tire and size of tire to brand and size. but generally take a look at the X-Chock products (you can see them at RV Stores)

This is basically a sizzors jack that goes between the front and rear tire on a dual axle Trailer.. If there's room to put it in and "Expand" it so as to lock the axles together.. you are good.

As long as they aren't touching, that should work... ;)

But, in general, it seems that leaving at least a couple of inches is the min..

Then, I've seen what looks like 12-18" between the tandem axle tires..

Good luck!

Mitch