Truck tires on tt?
We live in Florida & the summer heat destroys our tt tires. We keep them covered & don't drive over 65 mph, and yet, we blow tires every 2 years. We were advised by another RVer to use truck tires o...
Forum Discussion
crollman wrote:gmw photos wrote:
So yes indeed, it's good practice to follow the recommendations of the trailer manufacturer.
As a design engineer with 40yrs experience and two advanced degrees out of MIT, I disagree. It's in fact naïve to blindly follow manufacturer recommendations in the case of RVs, unfortunately.
The RV manufacturers ignore dynamic forces in sizing the tires they install and recommend for trailers. The result is that the tires will be overloaded when the trailer is in motion, and those overloads can be quite large (580lbs per tire in my case).
Carlisle Tire has a document "Trailer Tires: Tips & Best Practices" that offers solid advice about sizing trailer tires. They recommend taking the trailer gross weight, add 20%, and divide by the number of tires to get an appropriate load rating for trailer tires. The 20% margin will allow for dynamic forces. All of the brand new trailers from several manufacturers that I checked failed this test when loaded to the GVWR. You might try this calculation on your own trailer with factory tires installed and see how it compares.
The tire engineers here on the forum tell us that "the dynamic forces involved when the tires in motion" are accounted for in the specifications of the tires. To put it simply, the figures the tire manufacturer states include the forces exerted on the tire while in motion, such as "increases of weight loading when traversing bumps in the road at speed".
Which make sense, as it would be difficult indeed for us to foresee actual loads in motion.
