Tire inflation not the same for all trailers – more on Interply Shear

RV Tire Safety with RV tire expert Roger Marble I have written a number of times on the topic of Interply Shear. This is the force that is trying to tear the belts of radial tires apart. There are some highly technical papers on the topic and you can review them after a simple Google search on the term. You... Read More

Tire suffered belt separation, not a “zipper” failure

RV Tire Safety with RV tire expert Roger Marble Roger read a recent post on an RV forum about a tire that lost its tread (photo below right), and a response from another forum member about “zippering,” as follows: “Your tires look like they threw the whole tread off. I always assumed that the treads I see on the road... Read More

Tire failure could have been prevented with TPMS

RV Tire Safety with RV tire expert Roger Marble This tire failure was not a “blowout,” but definitely was a Run Low Sidewall Flex failure. The cause was not having a tire pressure monitoring system (TPMS). I read the following on an RV trailer forum: “BOOM, it happened again; however, this time it was with the upgraded Maxxis tires. It... Read More

More on why trailer tires fail more than tow vehicle tires

RV Tire Safety with RV tire expert Roger Marble On a thread on an RV trailer forum Peter made this statement: “At highway speeds interply shear is not as much of an issue, as I understand things.” I posted this reply: Speed itself is not the issue that causes interply shear in radial tires. Two things happen to radials when... Read More

Why do trailer tires fail more often than tow vehicle tires?

RV Tire Safety with RV tire expert Roger Marble Here is a question posted on a travel trailer forum: “Why so many trailer tire failures and so few, if any, tow vehicle tire failures?” This post could be considered Part 2 of my post of last week, How do you figure an ST-type tire’s maximum safe speed? The primary reason,... Read More

How do you figure an ST-type tire’s maximum safe speed?

RV Tire Safety with RV tire expert Roger Marble Originally posted on an online forum: “The 65 mph is not really correct. It depends on load and air pressure. They can go to 80 mph.” As I have pointed out previously: The load formula that populates the Load/Inflation table, used by the tire industry for ST-type tires, is based on the assumption... Read More

Pros(?) and cons of dual tire air balance systems

RV Tire Safety with RV tire expert Roger Marble I read a thread on an RV forum about connecting two tires in dual position, with hoses to “balance” the inflation pressure. There were some claims made about performance improvements, but IMO the conditions necessary to deliver those improvements are pretty extreme and improvements are tenuous. The information on the function... Read More

OK to support just one dual tire on leveling block?

RV Tire Safety with RV tire expert Roger Marble Question: “I have some questions about leveling with ramps, specifically on vehicles with rear duallies. The obvious temptation is to use only one ramp – and the obvious response is that this is a 2x overload condition and should be avoided. However, since tires and wheels are clearly designed with safety... Read More

Is using state scales for “four corner weights” wise?

RV Tire Safety with RV tire expert Roger Marble I was following a forum thread on using closed state scales to learn your “four corner weights.” This is possible in Washington, Oregon, and some other states.  Some commenters felt the practice was not wise as the area around the platform scale might not be perfectly flat. I posted my thoughts... Read More