Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
OK, I'll try this again but with a different tack.
I am of the opinion that ST tires should have a 15% reserve capacity (85% of the load at a given pressure) in order to be reasonably sure they won't fail. There are a couple of ways of estimating what the actual load is on a given tire of a trailer, but the best way is to actually measure each tire. The RMA has a procedure to follow:
http://www.rma.org/publications/tire_service_professionals/index.cfm?PublicationID=11516
I am of the opinion that this 15% reserve capacity is likely to require higher load ranges and larger sized ST tires - or both. And maybe even a step into LT type tires - and here is where it gets tricky.
While I feel uncomfortable recommending that LT tires be loaded to their maximum load, that is in essence the result. I feel uncomfortable with that because I don't have enough experience to say it with confidence. However, I have no hesitation in recommending replacing ST tires with LT tires if it can be done with enough clearances around the tire.
A couple of other points:
ST tires can be inflated 10 psi over the maximum pressure listed in the sidewall of the tire - and I'd recommend that if you can't get to a 15% reserve capacity.
Recent bulletins from the tire industry indicate that tires degrade simply due to time. The age of a tire is important even if the tire is unused.
There is some disagreement over how to best express this age limitation,
but my take is:
If you live in a hot climate (AZ, CA, NV, TX, and FL) then the limit is six years. If you live in a cold climate (MN, ND, WI, MT, etc), then the limit is 10 years. States in between are ..... ah ........ in between.
A rule of thumb for estimating if you need more load carrying capacity:
Check the cold (ambient temperature) tire pressure before starting off. Measure the inflation pressure after an hour of driving.
If the tire pressure build up is less than 10%, it's OK. If the pressure build up is between 10% and 15%, then continue to monitor until you are sure it is not above 15%. If the pressure buildup is 15% or greater, add load carrying capacity (and one of the ways to do that is to add pressure). For ST and LT tires, NEVER use more than 10 psi over the sidewall pressure.
Any questions?
I am of the opinion that ST tires should have a 15% reserve capacity (85% of the load at a given pressure) in order to be reasonably sure they won't fail. There are a couple of ways of estimating what the actual load is on a given tire of a trailer, but the best way is to actually measure each tire. The RMA has a procedure to follow:
http://www.rma.org/publications/tire_service_professionals/index.cfm?PublicationID=11516
I am of the opinion that this 15% reserve capacity is likely to require higher load ranges and larger sized ST tires - or both. And maybe even a step into LT type tires - and here is where it gets tricky.
While I feel uncomfortable recommending that LT tires be loaded to their maximum load, that is in essence the result. I feel uncomfortable with that because I don't have enough experience to say it with confidence. However, I have no hesitation in recommending replacing ST tires with LT tires if it can be done with enough clearances around the tire.
A couple of other points:
ST tires can be inflated 10 psi over the maximum pressure listed in the sidewall of the tire - and I'd recommend that if you can't get to a 15% reserve capacity.
Recent bulletins from the tire industry indicate that tires degrade simply due to time. The age of a tire is important even if the tire is unused.
There is some disagreement over how to best express this age limitation,
but my take is:
If you live in a hot climate (AZ, CA, NV, TX, and FL) then the limit is six years. If you live in a cold climate (MN, ND, WI, MT, etc), then the limit is 10 years. States in between are ..... ah ........ in between.
A rule of thumb for estimating if you need more load carrying capacity:
Check the cold (ambient temperature) tire pressure before starting off. Measure the inflation pressure after an hour of driving.
If the tire pressure build up is less than 10%, it's OK. If the pressure build up is between 10% and 15%, then continue to monitor until you are sure it is not above 15%. If the pressure buildup is 15% or greater, add load carrying capacity (and one of the ways to do that is to add pressure). For ST and LT tires, NEVER use more than 10 psi over the sidewall pressure.
Any questions?
