Keystone RV Forums - View Single Post

Tireman9 · 03-12-2019, 09:54 AM

The inflation on a tire sidewall is the MINIMUM inflation pressure needed to support the MAXIMUM load (aosomolded o the tire sidewall).
There is a sound scientific reason to run higher inflation whe running tires on multi-axle trailers. It is called "Interply Shear". This force is what can result in belt/tread separtions. I have covered this in detail along with references to technical papers on the topic.
IMO you need a minimum of 15% "head-room" of load capacity over the leasuredload of the heavier end of an axle. (CAT scale only geves the total on an axle and very few RVs have 50/50 load split. Some oflks have discovered unbalance of 500 to 1,000#)
Most cars come with 20% to 40% tire load capacity headroom. I run 25% on my Class-C.

03-12-2019, 09:54 AM	#56
Tireman9 Senior Member Join Date: Sep 2018 Location: Akron Posts: 459	The inflation on a tire sidewall is the MINIMUM inflation pressure needed to support the MAXIMUM load (aosomolded o the tire sidewall). There is a sound scientific reason to run higher inflation whe running tires on multi-axle trailers. It is called "Interply Shear". This force is what can result in belt/tread separtions. I have covered this in detail along with references to technical papers on the topic. IMO you need a minimum of 15% "head-room" of load capacity over the leasuredload of the heavier end of an axle. (CAT scale only geves the total on an axle and very few RVs have 50/50 load split. Some oflks have discovered unbalance of 500 to 1,000#) Most cars come with 20% to 40% tire load capacity headroom. I run 25% on my Class-C. __________________ Retired Tire Design Engineer (40 years). Serve on FMCA Tech Advisory Committee. Write a blog RV Tire Safety. Read THIS post on Why Tires Fail.