QuestionI have a 5,000 pound travel trailer. A tire company sold me 4 Carlisle tires.....ST205/75R/15 with 2 ply sidewalls. Upon installation, the sidewalls seem to bulge out quite a bit as if they're not very sturdy. Are 2 ply sidewalls sufficient for a 5,000 lb. trailer ??
AnswerDear Bill,
Thank you for using AllExperts.
This size is available on the market in load range the following load ranges:
B with max. load of 1,480 lbs. per tire @ 35 psi
C with max. load of 1,820 lbs. per tire @ 50 psi
D with max. load of 2,150 lbs. per tire @ 65 psi
All manufacturer's of ST205/75R15 would have the same load rating, regardless of the actual amount of "plies" or internal construction of the tire. Radial tires typically have two plies and bulge out at the bottom whereas bias-ply ST type tires may not.
Even the load range 'B' should be sufficient to carry 5,000 lbs over four tires IF the load is spread equally over all four tires and if the tires are inflated properly. Depending on the trailer loading (load distribution) and suspension type, each tire on the trailer may not be taking its share of the load and one or more tires may be overloaded. My advice would be to weigh the trailer at the first opportunity by axle and make sure you are within its carrying capacity. Check the tires you have...if they are load range 'B' put 35 psi in them.
Contact me with any further questions.
Some tips on RV weighing:
http://www.your-rv-lifestyle.com/rv-weight.html
