LT tires for my fifth wheel
#1
09-01-2014, 11:42 AM
LT tires for my fifth wheel
The Towmax STR Powerking 235/75r16E's that came on my fiver made it about 3 years and 4k miles before two of them failed. Luckily, between traffic lights, a guy got my attention to let me know that I had a huge bubble on the side of one of them. He certainly saved me from a blowout. So now I'm researching replacement tires and the general consensus seems to be that ST tires are crap and the thing to do is go to an LT. I'm looking for some good advice in this area. What have you tried? What should I stay away from? <O
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#2
09-01-2014, 12:23 PM
Depends on the weight of your 5ver. If it has 6k axles, then the Michelin XPS Rib is the number one choice followed by Bridgestone Duravis. If you have 7k axles, the Goodyear G614's are the best but expensive at around 325 per. The second choice in this class is the Sailun S637 which is about half the price. Both the Goodyear and Sailun are G rated tires and require rims that are rated to 110 lbs PSI. Rims are generally stamped on the back side with their max pressure. I personally run he Goodyear's and now only think about tire failures when reading about them on the forums... Hope this helps....
PS If your rims are only rated to 80 psi and you are on 7k axles, then your best bet is to pass on the G tires and go straight to a 17.5 tire and wheel package. Good package deals can be found at trailertiresandwheels.com.
PS If your rims are only rated to 80 psi and you are on 7k axles, then your best bet is to pass on the G tires and go straight to a 17.5 tire and wheel package. Good package deals can be found at trailertiresandwheels.com.
#3
09-01-2014, 01:06 PM
I went straight to G614's.. (had the dealer install them before pickup) Goodyear has a very good reputation for paying for repair of rv damage cause by tire failure (keep the carcass until they tell you that you don't need it). Sailun does not have that kind of coverage.
I also just added a TST TPMS system to my truck and trailer.
and my enclosed car hauler too. (E tires on twin 3500 lb axles).
I also just added a TST TPMS system to my truck and trailer.
and my enclosed car hauler too. (E tires on twin 3500 lb axles).
#4
09-01-2014, 01:18 PM
I went from 235/80-16 ST tires to 235/85-16 E rated Cooper tires. If you do a study on how tires are rated, under what conditions and what the difference in the testing standards are between LT and ST tires you will understand why many RV'ers do the same.
I chose Cooper because they are produced in the USA where you will not find an ST tire that is not an import in a 16" tire size.
Do the research for yourself, be comfortable with your decision and go LT.
FWIW, our 5th wheel with Power King or whatever the China brand was had two blow outs in less than 1K miles and they were new.
I chose Cooper because they are produced in the USA where you will not find an ST tire that is not an import in a 16" tire size.
Do the research for yourself, be comfortable with your decision and go LT.
FWIW, our 5th wheel with Power King or whatever the China brand was had two blow outs in less than 1K miles and they were new.
#5
09-01-2014, 01:31 PM
A Great wealth of information here from a gentleman from when I post this same question on an RV site.
************************************************** ***********
This debate will be entertained until there are no more RV's, so with that, for inquiring minds with an afternoon of spare time to read and research the references, here is one of the best informative writings on the ST vs LT that I have read. I copied it from a post on the Montana owners site where a very lively discussion ensued for days.
Here is the info a guy compiled from the government site on tire testing....
SUMMARY OF FINDINGS & CONCLUSIONS
I found the testing requirements for both the ST and LT tires at the Federal Motor Carrier Safety Administration (FMCSA) webpage.
The testing for each tire is comprised of (1) bead unseating resistance, (2) strength, (3) endurance, and (4) high speed performance.
The testing for (1) bead unseating resistance and (2) strength were identical for tires representative of moderate to heavy 5th wheels and thus no advantage is given to either tire type.
The testing for (3) endurance was found to be significantly different between the ST and LT tires.
Both the ST and LT are put through the same initial pressure, time and load profile. The total profile lasts 34 hours of continuous run time starting at 85% of rated load and ending at 100% of rated load. To further stress the tires, a load range E tire (nominal 80 psi rating) is tested at a reduced pressure of 60 psi to induce additional load on the tire during testing. (This is reasonable that testing should be conservative.)
But now the endurance testing diverges significantly.
The ST tire is tested at this pressure, time and load profile at 50 mph. After that, the ST test is over.
The LT tire is tested at this pressure, time and load profile at 75 mph. This is a 50% increase over the ST and will induce significant additional load and heating on the tire during testing. After that, the LT test is not complete. Next a “Low Inflation Pressure Performance” test is performed for the LT tire only. The tire pressure is decreased to 46 psi and the tire is immediately run for an additional 2 hours at 75 mph and 100% of rated load.
Thus, the LT tire endurance test is drastically more intense than the ST endurance test.
The testing for (4) high speed performance.
The difference in high speed performance testing between a ST and LT tire is significant. Both tires are tested through a 90 minute speed/time profile.
The ST tire is tested 88% of rated load while the LT tire is tested at 85% of rated load. Thus, the loading is 3% higher based on rated load and this slight advantage goes to the ST tire.
However, the LT tire is tested at significantly higher velocities when compared to a ST tire (99 vs. 85 mph maximum speed). This is a 16% advantage to the LT tire.
Thus, again the overall test for the LT is more rigorous than the ST test.
Conclusion:
It is reasonable to conclude that these test requirements force the tire manufacturer to construct an LT tire more substantially than an ST tire. This is also a reasonable explanation for the same size LT tire is rated at a slightly lower maximum load than a ST tire.
And now, for those of you who need to know all the details, read on!
REFERENCES
The references for my evaluation may be found at the Federal Motor Carrier Safety Administration (FMCSA) webpage:
ST tire standard may be found at FMCSA Part 571, subsection 109.
http://www.fmcsa.dot...90163348008f295
LT tire standard may be found at FMCSA Part 571, subsection 139.
http://www.fmcsa.dot...90163348008f2a9
Part 571, subsection 139 references Part 571 subsection 119 which can be found at:
http://www.fmcsa.dot...90163348008f29d
QUICK NOTES
Each standard for the ST and LT tires has definitions, significant constraints on labeling, etc. that I will not address. There are also tire conditioning (temperature), tire break in, etc. that are the same or similar for ST and LT that I will not address. The details are in the references.
The (3) endurance, and (4) high speed performance tests must not result in tire failure. Tire failure includes visual evidence of tread, sidewall, ply, cord, inner liner, or bead separation, chunking, broken cords, cracking, or open splices, not just a blowout.
TESTING - BEAD UNSEATING RESISTANCE
ST Tire: (reference paragraph S5.2.2)
The tire is mounted horizontally and a vertical load is applied to the tire’s outer sidewall at a rate of 50 mm (2 inches) per minute.
Increase the load until the bead unseats or a specified value is reached.
Repeat the test at least four places equally spaced around the tire circumference.
LT Tire:
Paragraph “S6.6 Tubeless tire bead unseating resistance” references the ST tire procedure noted above.
Conclusion:
The testing for bead unseating resistance is identical for a ST and LT tire.
TESTING - STRENGTH
ST Tire: (reference paragraph S5.3.2.1)
Force a 19 mm (3?4 inch) diameter cylindrical steel plunger with a hemispherical end perpendicularly into the tread rib as near to the centerline as possible, avoiding penetration into the tread groove, at the rate of 50 mm (2 inches) per minute.
Compute the breaking energy for each test point by means of a provided formula.
LT Tire: (reference paragraph S6.5.2)
Each tire shall comply with the requirements of S7.3 of 571.119, which is tires for vehicles weighing 10,000 lb or more. Per S7.3 of 571.119 for our example tire, the testing is the same as the ST tire procedure noted above.
Conclusion:
The testing for strength is identical for a ST and LT tire.
TESTING - ENDURANCE
The following is for a ST or LT tire of less than nominal cross section less than or equal to 295 mm (11.5 inches) which is typical of a 5th wheel application.
ST tire: (reference paragraph S5.4.2)
There are specifications for the contact of the tire mounted on a test axle and steel test wheel after the test that I will not address because they are similar for the ST and LT.
Inflate a load range E to 60 psi. (410 kPa)
Conduct the test at 80 kilometers per hour (km/h)(50 miles per hour) in accordance with the following schedule without pressure adjustment or other interruptions:
The loads for the following periods are the specified percentage of the maximum load rating marked on the tire sidewall:
Time and Percent of rated load
4 hours, 85%
6 hours, 90%
24 hours, 100%
LT Tire: (reference paragraph S6.3.1.2)
“Conduct the test, without interruptions, at the test speed of not less than 120 km/h…” (75 mph)
Inflate a load range E to 60 psi. (410 kPa)
This test uses the same profile as the ST tire.
Immediately following the above sequence perform a Low Inflation Pressure Performance test (reference paragraph S6.4):
This test uses the same tire/wheel as the previous sequence at a reduced pressure.
For a load range E tire the pressure is reduced to 46 psi. (320 kPa)
The same tire/wheel is run an additional 2 hours at the reduced pressure at a speed of 75 mph and 100% of rated load.
Conclusion:
The difference in endurance testing between a ST and LT tire is significant. Both tires are tested through a equivalent loading/time profile. However, the LT tire is tested at this profile at a higher speed (75 vs. 50 mph) and must still endure an additional 2 hour low pressure test without failure. Thus the overall test for the LT is far more rigorous than the ST test.
TESTING - HIGH SPEED PERFORMANCE
ST tire: (reference paragraph S5.5.4)
Load the tire to 88 percent of the tire’s maximum load rating as marked on the tire sidewall. Inflate to 72 psi (500 kPa). Run the test sequentially without interruption at:
75 mph (121 km/h) for 30 minutes
80 mph (129 km/h) for 30 minutes
85 mph (137 km/h) for 30 minutes
LT Tire: (reference paragraph S6.2.1.2.7)
Load the tire to 85 percent of the tire’s maximum load rating as marked on the tire sidewall. Inflate to 72 psi (500 kPa). Run the test sequentially without interruption at:
87 mph (140 km/h) for 30 minutes
93 mph (150 km/h) for 30 minutes
99 mph (160 km/h) for 30 minutes
Conclusion:
The difference in high speed performance testing between a ST and LT tire is significant. Both tires are tested through a speed/time profile. The ST tire is tested 88% of rated load while the LT tire is tested at 85% of rated load. Thus, the loading is 3% higher based on rated load and this slight advantage goes to the ST tire. However, the LT tire is tested at significantly higher velocities (nearly 100 mph!) when compared to a ST tire. This is a 16% advantage to the LT tire. Thus, again the overall test for the LT is more rigorous than the ST test.
************************************************** ***********
This debate will be entertained until there are no more RV's, so with that, for inquiring minds with an afternoon of spare time to read and research the references, here is one of the best informative writings on the ST vs LT that I have read. I copied it from a post on the Montana owners site where a very lively discussion ensued for days.
Here is the info a guy compiled from the government site on tire testing....
SUMMARY OF FINDINGS & CONCLUSIONS
I found the testing requirements for both the ST and LT tires at the Federal Motor Carrier Safety Administration (FMCSA) webpage.
The testing for each tire is comprised of (1) bead unseating resistance, (2) strength, (3) endurance, and (4) high speed performance.
The testing for (1) bead unseating resistance and (2) strength were identical for tires representative of moderate to heavy 5th wheels and thus no advantage is given to either tire type.
The testing for (3) endurance was found to be significantly different between the ST and LT tires.
Both the ST and LT are put through the same initial pressure, time and load profile. The total profile lasts 34 hours of continuous run time starting at 85% of rated load and ending at 100% of rated load. To further stress the tires, a load range E tire (nominal 80 psi rating) is tested at a reduced pressure of 60 psi to induce additional load on the tire during testing. (This is reasonable that testing should be conservative.)
But now the endurance testing diverges significantly.
The ST tire is tested at this pressure, time and load profile at 50 mph. After that, the ST test is over.
The LT tire is tested at this pressure, time and load profile at 75 mph. This is a 50% increase over the ST and will induce significant additional load and heating on the tire during testing. After that, the LT test is not complete. Next a “Low Inflation Pressure Performance” test is performed for the LT tire only. The tire pressure is decreased to 46 psi and the tire is immediately run for an additional 2 hours at 75 mph and 100% of rated load.
Thus, the LT tire endurance test is drastically more intense than the ST endurance test.
The testing for (4) high speed performance.
The difference in high speed performance testing between a ST and LT tire is significant. Both tires are tested through a 90 minute speed/time profile.
The ST tire is tested 88% of rated load while the LT tire is tested at 85% of rated load. Thus, the loading is 3% higher based on rated load and this slight advantage goes to the ST tire.
However, the LT tire is tested at significantly higher velocities when compared to a ST tire (99 vs. 85 mph maximum speed). This is a 16% advantage to the LT tire.
Thus, again the overall test for the LT is more rigorous than the ST test.
Conclusion:
It is reasonable to conclude that these test requirements force the tire manufacturer to construct an LT tire more substantially than an ST tire. This is also a reasonable explanation for the same size LT tire is rated at a slightly lower maximum load than a ST tire.
And now, for those of you who need to know all the details, read on!
REFERENCES
The references for my evaluation may be found at the Federal Motor Carrier Safety Administration (FMCSA) webpage:
ST tire standard may be found at FMCSA Part 571, subsection 109.
http://www.fmcsa.dot...90163348008f295
LT tire standard may be found at FMCSA Part 571, subsection 139.
http://www.fmcsa.dot...90163348008f2a9
Part 571, subsection 139 references Part 571 subsection 119 which can be found at:
http://www.fmcsa.dot...90163348008f29d
QUICK NOTES
Each standard for the ST and LT tires has definitions, significant constraints on labeling, etc. that I will not address. There are also tire conditioning (temperature), tire break in, etc. that are the same or similar for ST and LT that I will not address. The details are in the references.
The (3) endurance, and (4) high speed performance tests must not result in tire failure. Tire failure includes visual evidence of tread, sidewall, ply, cord, inner liner, or bead separation, chunking, broken cords, cracking, or open splices, not just a blowout.
TESTING - BEAD UNSEATING RESISTANCE
ST Tire: (reference paragraph S5.2.2)
The tire is mounted horizontally and a vertical load is applied to the tire’s outer sidewall at a rate of 50 mm (2 inches) per minute.
Increase the load until the bead unseats or a specified value is reached.
Repeat the test at least four places equally spaced around the tire circumference.
LT Tire:
Paragraph “S6.6 Tubeless tire bead unseating resistance” references the ST tire procedure noted above.
Conclusion:
The testing for bead unseating resistance is identical for a ST and LT tire.
TESTING - STRENGTH
ST Tire: (reference paragraph S5.3.2.1)
Force a 19 mm (3?4 inch) diameter cylindrical steel plunger with a hemispherical end perpendicularly into the tread rib as near to the centerline as possible, avoiding penetration into the tread groove, at the rate of 50 mm (2 inches) per minute.
Compute the breaking energy for each test point by means of a provided formula.
LT Tire: (reference paragraph S6.5.2)
Each tire shall comply with the requirements of S7.3 of 571.119, which is tires for vehicles weighing 10,000 lb or more. Per S7.3 of 571.119 for our example tire, the testing is the same as the ST tire procedure noted above.
Conclusion:
The testing for strength is identical for a ST and LT tire.
TESTING - ENDURANCE
The following is for a ST or LT tire of less than nominal cross section less than or equal to 295 mm (11.5 inches) which is typical of a 5th wheel application.
ST tire: (reference paragraph S5.4.2)
There are specifications for the contact of the tire mounted on a test axle and steel test wheel after the test that I will not address because they are similar for the ST and LT.
Inflate a load range E to 60 psi. (410 kPa)
Conduct the test at 80 kilometers per hour (km/h)(50 miles per hour) in accordance with the following schedule without pressure adjustment or other interruptions:
The loads for the following periods are the specified percentage of the maximum load rating marked on the tire sidewall:
Time and Percent of rated load
4 hours, 85%
6 hours, 90%
24 hours, 100%
LT Tire: (reference paragraph S6.3.1.2)
“Conduct the test, without interruptions, at the test speed of not less than 120 km/h…” (75 mph)
Inflate a load range E to 60 psi. (410 kPa)
This test uses the same profile as the ST tire.
Immediately following the above sequence perform a Low Inflation Pressure Performance test (reference paragraph S6.4):
This test uses the same tire/wheel as the previous sequence at a reduced pressure.
For a load range E tire the pressure is reduced to 46 psi. (320 kPa)
The same tire/wheel is run an additional 2 hours at the reduced pressure at a speed of 75 mph and 100% of rated load.
Conclusion:
The difference in endurance testing between a ST and LT tire is significant. Both tires are tested through a equivalent loading/time profile. However, the LT tire is tested at this profile at a higher speed (75 vs. 50 mph) and must still endure an additional 2 hour low pressure test without failure. Thus the overall test for the LT is far more rigorous than the ST test.
TESTING - HIGH SPEED PERFORMANCE
ST tire: (reference paragraph S5.5.4)
Load the tire to 88 percent of the tire’s maximum load rating as marked on the tire sidewall. Inflate to 72 psi (500 kPa). Run the test sequentially without interruption at:
75 mph (121 km/h) for 30 minutes
80 mph (129 km/h) for 30 minutes
85 mph (137 km/h) for 30 minutes
LT Tire: (reference paragraph S6.2.1.2.7)
Load the tire to 85 percent of the tire’s maximum load rating as marked on the tire sidewall. Inflate to 72 psi (500 kPa). Run the test sequentially without interruption at:
87 mph (140 km/h) for 30 minutes
93 mph (150 km/h) for 30 minutes
99 mph (160 km/h) for 30 minutes
Conclusion:
The difference in high speed performance testing between a ST and LT tire is significant. Both tires are tested through a speed/time profile. The ST tire is tested 88% of rated load while the LT tire is tested at 85% of rated load. Thus, the loading is 3% higher based on rated load and this slight advantage goes to the ST tire. However, the LT tire is tested at significantly higher velocities (nearly 100 mph!) when compared to a ST tire. This is a 16% advantage to the LT tire. Thus, again the overall test for the LT is more rigorous than the ST test.
#6
09-01-2014, 01:36 PM
More Turbo
#7
09-01-2014, 02:04 PM
Trailer Tires:
Tips & Best Practices
From a highway blowout to a construction trailer flat on the work site,
trailer tire failure is an inconvenience that can be avoided. Use the
correct tires, calculate the correct load and maintain the right inflation
to avoid problems.
Use the Right Tire
Trailer tire requirements differ greatly from automotive or light truck
tires. Trailer tires are designated “ST” for Special Trailer tires.
Automotive tires are designated “P” for Passenger or “LT” for Light
Truck and are not designed for trailer use. Passenger or truck tires,
with their more flexible sidewalls, can result in trailer sway problems.
The stiffer, heavy duty sidewalls of ST tires are designed to control
and reduce sway problems. Trailer sway is dangerous at higher
speeds, with top heavy loads or on vehicles with inadequate
tongue weight.
– Trailer tires are designed for use on trailer axle positions only.
– Do not use P Passenger or LT Light Truck automotive tires
on trailers.
– Do not use ST trailer tires on passenger cars or light trucks.
– An "LT" designation, when shown on a trailer tire size specifies load
range only, it is not designed for use on light trucks.
The ST Difference
The construction, design, materials and testing used in ST Special
Trailer tires meet the higher load requirements, duty cycles and
special demands of trailering.
– Polyester cords in an ST tire are bigger than in a comparable P or
LT tire.
– Steel cords used in ST tires have a larger diameter and greater
tensile strength to meet additional load requirements.
– ST tire rubber compounds contain chemicals to resist weather and
ozone cracking, particularly conditions resulting from extended
storage and the unusual duty cycles of trailer tires.
– The slightly shallower tread depth of a trailer tire reduces sway and
rides cooler, which adds to tire longevity.
– ST tires feature stiffer sidewalls, especially in the lower
section which:
– Reduces sidewall flexing causing the trailer to track straighter.
– Diminishes the risk of trailer sway.
– Lessens the risk of sidewall puncture and blowout.
– ST tires generally offer approximately 10% percent more load
capacity than a similar LT tire and nearly 40% more than a P
passenger tire.
Bias vs. Radial
Some ST trailer tires are bias-ply tires, which have crisscrossing cords
of polyester and/or nylon. Trailer tires are also offered in radial
construction. Radial trailer tires feature plies that run perpendicularly
across the tire, with belts (some made of steel) running under
the tread.
– Bias-ply trailer tires are recommended for tough, rugged
performance and sidewall puncture resistance such as trailers used
for construction, agriculture and some marine applications.
– Radial tires are recommended when smooth ride, tread wear, heat
and extended tire life are important considerations. Depending upon
the trailer duty cycle (storage time vs. actual time in use under load)
the mileage expectation of radial trailer tire can be from 5,000 to
12,000 miles. However, under well maintained conditions, proper
inflation and correct loads, considerably higher miles have
been reported.
Load Limits
Trailers are used for one purpose, transporting loads. A major cause
of trailer tire failure is overloading. It's important to know the weight
of the actual load of the payload under tow, including all the toys,
equipment, gas, gear, water and the trailer itself. An over-loaded tire
will produce excessive heat in the sidewall and tread which can
quickly cause tire degradation or blowout. Excessive heat is the
number one cause of trailer tire failure. The problem increases in
sunbelt areas where roadway surface temperatures are well above
normal conditions.
All tires are manufactured to handle specific load limits, but in towing
trailers, loads are the single greatest concern. Review the tire
sidewall information and the vehicle owner's manual for vehicle load
limits and proper tire inflation. Never exceed the maximum load rating
stamped on the tire sidewall or the maximum vehicle load rating,
whichever is less. If possible, try to distribute the load evenly across
all tires so that no single tire is overloaded. Tongue weight, tongue
height and especially load leveling hitches must be set properly to
avoid overloading the trailer tires.
ST tires are branded with a load range (LRB, LRC, LRD, LRE and LRF)
on the sidewall, listing load range letters in the sidewall description.
For example, ST205/75R15LRD.
Discuss specific trailer uses to select the ST tire that is load rated for
the situation.
– All tires must be identical in size for the tires to properly manage the
weight of the trailer.
– The combined capacity of the tires must equal or exceed the Gross
Vehicle Weight (GVW) of the axle.
– The combined capacity of all of the tires should exceed the loaded
trailer weight by 20 percent.
– If a tire fails on a tandem axle trailer, replace both tires on that side.
– If the tires are replaced with tires of a larger diameter, the tongue
height may need to be adjusted to maintain proper
weight distribution.
Inflation
Underinflation is the number one cause of trailer tire failure. Low
inflation pressure elevates tread temperature, especially as speed
increases. A tire can lose up to half of its air pressure and not appear
Trailer Tires: Tips & Best Practices
carlisletransportationproducts.com
Trailer Tires:
Understanding Tire Sidewall Information
Ratio of height to
width (aspect ratio)
Radial Rim Diameter Code
Maximum Load Rating
Maximum Permissible
Inflation Pressure
Tire Ply
Composition
& Materials
Used
Warning Label
ST for
Special
Trailer
Tire Type
Load Range
Nominal Width of
Tire in Millimeters
carlisletransportationproducts.com
U.S.
DOT I.D. No.
Date Code
to be flat. Check inflation with a quality tire gauge. Operation of a
trailer tire that is 30 percent under-inflated can reduce tire lifespan by
approximately 55%. An underinflated tire creates abnormal tire
flexing and excessive heat causing the following:
– Tire damage and failure.
– Ride and handling disturbance.
– Reduction of tire life.
– Decreased fuel efficiency by as much as 10 percent.
Driving on tires with too much air is also not recommended.
Over-inflated tires are more likely to cut, puncture or fail by
sudden impact.
When replacing trailer tires, always use new valve stems.
Replacement of Trailer Tires
Trailer tires can be worn beyond use although they may appear to
have adequate tread. This is because trailer tires support a lot of
weight, even when not in use. It is actually better for a tire to be rolling
down the road than to sit in storage, exposed to static weight and UV
exposure. During use a tire releases compound lubricants that are
beneficial to tire life. Using tires also assists in preventing flat spots
from developing.
If one tire fails, the remaining tires will be required to suddenly
compensate by supporting the increased load. This increase of weight
may overload the other tires causing a chain reaction blowout or other
internal structural damage. After a blowout, check the other tires for
damage and replace all tires on the side of the blowout.
Best Practices
– Any tire, no matter how well constructed, may fail when in use
because of punctures, impact damage, improper inflation,
overloading, or other conditions resulting from use, misuse
or neglect.
– High speed towing in hot conditions degrades tires significantly.
– Best practice. Do not exceed 60 mph while towing a trailer.
– Most ST trailer tires have a maximum speed rating of 65 mph.
– Load carrying capacity decreases as heat and stress generated by
higher speed increases.
– Time and the elements weaken a trailer tire.
– 3 to 5 years is the average life expectancy of a trailer tire,
regardless of mileage.
– It is estimated that in approximately three years, roughly
one-third of a tire's strength is gone.
– After three years, depending upon storage and conditions of
usage, consider replacing trailer tires even if they have tread
depth remaining.
– After five years, trailer tires should be replaced in all cases.
Review - Practices for Safe Trailer Tire Use
– Select the correct tires to match the application and
capacity requirements.
– Never use passenger car or truck tires for trailer use.
– Do not overload trailer tires, maximum loads are listed on the
sidewall of the tire.
– Maintain air pressure at the maximum PSI recommended on the
tire sidewall.
– Check tire pressure when tires are cold and in the shade.
– Use a cap on valve stems to prevent contamination of the internal
rubber valve.
– Always travel with a spare and check the spare air pressure along
with the other tires.
– Perform a visual inspection of trailer tires before each trip,
inspecting for cuts, bulges, punctures or signs of anything unusual.
– Inspect trailer wheels. If rims are bent or cracked, replacement or
repair may be necessary.
– Keep trailer tires in a cool dry place and out of direct sunlight
during storage.
– Use tire covers to protect tires from the harsh effects of direct
sunlight, moisture and temperature extremes.
– During extended storage, use a thin piece of wood or other surface
barrier under tires to extend tire life. For seasonal or extreme long
term storage, elevate the trailer on blocks to take the weight off the
tires. Reduce the air pressure and cover the tires to protect them
from direct sunlight.
– Replace trailer tires every three to five years.
– If you experience a series of successive blowouts, something is
wrong with your setup, it is not a tire problem.
When it's replacement time, Carlisle offers a complete line of tires
designed for most towing applications. Whether your precious cargo
is your new bass boat, construction equipment or a family travel
trailer, enjoy long, safe travels using the correct tires,
properly inflated and within the designated
load capacity.
The Carlisle Radial TrailRH.
Tow with Trust
™.
Official Tire - American Bass Anglers Tour.
Trailer Tires:
Tips & Best Practices, Continued
carlisletransportationproducts.com
Tips & Best Practices
From a highway blowout to a construction trailer flat on the work site,
trailer tire failure is an inconvenience that can be avoided. Use the
correct tires, calculate the correct load and maintain the right inflation
to avoid problems.
Use the Right Tire
Trailer tire requirements differ greatly from automotive or light truck
tires. Trailer tires are designated “ST” for Special Trailer tires.
Automotive tires are designated “P” for Passenger or “LT” for Light
Truck and are not designed for trailer use. Passenger or truck tires,
with their more flexible sidewalls, can result in trailer sway problems.
The stiffer, heavy duty sidewalls of ST tires are designed to control
and reduce sway problems. Trailer sway is dangerous at higher
speeds, with top heavy loads or on vehicles with inadequate
tongue weight.
– Trailer tires are designed for use on trailer axle positions only.
– Do not use P Passenger or LT Light Truck automotive tires
on trailers.
– Do not use ST trailer tires on passenger cars or light trucks.
– An "LT" designation, when shown on a trailer tire size specifies load
range only, it is not designed for use on light trucks.
The ST Difference
The construction, design, materials and testing used in ST Special
Trailer tires meet the higher load requirements, duty cycles and
special demands of trailering.
– Polyester cords in an ST tire are bigger than in a comparable P or
LT tire.
– Steel cords used in ST tires have a larger diameter and greater
tensile strength to meet additional load requirements.
– ST tire rubber compounds contain chemicals to resist weather and
ozone cracking, particularly conditions resulting from extended
storage and the unusual duty cycles of trailer tires.
– The slightly shallower tread depth of a trailer tire reduces sway and
rides cooler, which adds to tire longevity.
– ST tires feature stiffer sidewalls, especially in the lower
section which:
– Reduces sidewall flexing causing the trailer to track straighter.
– Diminishes the risk of trailer sway.
– Lessens the risk of sidewall puncture and blowout.
– ST tires generally offer approximately 10% percent more load
capacity than a similar LT tire and nearly 40% more than a P
passenger tire.
Bias vs. Radial
Some ST trailer tires are bias-ply tires, which have crisscrossing cords
of polyester and/or nylon. Trailer tires are also offered in radial
construction. Radial trailer tires feature plies that run perpendicularly
across the tire, with belts (some made of steel) running under
the tread.
– Bias-ply trailer tires are recommended for tough, rugged
performance and sidewall puncture resistance such as trailers used
for construction, agriculture and some marine applications.
– Radial tires are recommended when smooth ride, tread wear, heat
and extended tire life are important considerations. Depending upon
the trailer duty cycle (storage time vs. actual time in use under load)
the mileage expectation of radial trailer tire can be from 5,000 to
12,000 miles. However, under well maintained conditions, proper
inflation and correct loads, considerably higher miles have
been reported.
Load Limits
Trailers are used for one purpose, transporting loads. A major cause
of trailer tire failure is overloading. It's important to know the weight
of the actual load of the payload under tow, including all the toys,
equipment, gas, gear, water and the trailer itself. An over-loaded tire
will produce excessive heat in the sidewall and tread which can
quickly cause tire degradation or blowout. Excessive heat is the
number one cause of trailer tire failure. The problem increases in
sunbelt areas where roadway surface temperatures are well above
normal conditions.
All tires are manufactured to handle specific load limits, but in towing
trailers, loads are the single greatest concern. Review the tire
sidewall information and the vehicle owner's manual for vehicle load
limits and proper tire inflation. Never exceed the maximum load rating
stamped on the tire sidewall or the maximum vehicle load rating,
whichever is less. If possible, try to distribute the load evenly across
all tires so that no single tire is overloaded. Tongue weight, tongue
height and especially load leveling hitches must be set properly to
avoid overloading the trailer tires.
ST tires are branded with a load range (LRB, LRC, LRD, LRE and LRF)
on the sidewall, listing load range letters in the sidewall description.
For example, ST205/75R15LRD.
Discuss specific trailer uses to select the ST tire that is load rated for
the situation.
– All tires must be identical in size for the tires to properly manage the
weight of the trailer.
– The combined capacity of the tires must equal or exceed the Gross
Vehicle Weight (GVW) of the axle.
– The combined capacity of all of the tires should exceed the loaded
trailer weight by 20 percent.
– If a tire fails on a tandem axle trailer, replace both tires on that side.
– If the tires are replaced with tires of a larger diameter, the tongue
height may need to be adjusted to maintain proper
weight distribution.
Inflation
Underinflation is the number one cause of trailer tire failure. Low
inflation pressure elevates tread temperature, especially as speed
increases. A tire can lose up to half of its air pressure and not appear
Trailer Tires: Tips & Best Practices
carlisletransportationproducts.com
Trailer Tires:
Understanding Tire Sidewall Information
Ratio of height to
width (aspect ratio)
Radial Rim Diameter Code
Maximum Load Rating
Maximum Permissible
Inflation Pressure
Tire Ply
Composition
& Materials
Used
Warning Label
ST for
Special
Trailer
Tire Type
Load Range
Nominal Width of
Tire in Millimeters
carlisletransportationproducts.com
U.S.
DOT I.D. No.
Date Code
to be flat. Check inflation with a quality tire gauge. Operation of a
trailer tire that is 30 percent under-inflated can reduce tire lifespan by
approximately 55%. An underinflated tire creates abnormal tire
flexing and excessive heat causing the following:
– Tire damage and failure.
– Ride and handling disturbance.
– Reduction of tire life.
– Decreased fuel efficiency by as much as 10 percent.
Driving on tires with too much air is also not recommended.
Over-inflated tires are more likely to cut, puncture or fail by
sudden impact.
When replacing trailer tires, always use new valve stems.
Replacement of Trailer Tires
Trailer tires can be worn beyond use although they may appear to
have adequate tread. This is because trailer tires support a lot of
weight, even when not in use. It is actually better for a tire to be rolling
down the road than to sit in storage, exposed to static weight and UV
exposure. During use a tire releases compound lubricants that are
beneficial to tire life. Using tires also assists in preventing flat spots
from developing.
If one tire fails, the remaining tires will be required to suddenly
compensate by supporting the increased load. This increase of weight
may overload the other tires causing a chain reaction blowout or other
internal structural damage. After a blowout, check the other tires for
damage and replace all tires on the side of the blowout.
Best Practices
– Any tire, no matter how well constructed, may fail when in use
because of punctures, impact damage, improper inflation,
overloading, or other conditions resulting from use, misuse
or neglect.
– High speed towing in hot conditions degrades tires significantly.
– Best practice. Do not exceed 60 mph while towing a trailer.
– Most ST trailer tires have a maximum speed rating of 65 mph.
– Load carrying capacity decreases as heat and stress generated by
higher speed increases.
– Time and the elements weaken a trailer tire.
– 3 to 5 years is the average life expectancy of a trailer tire,
regardless of mileage.
– It is estimated that in approximately three years, roughly
one-third of a tire's strength is gone.
– After three years, depending upon storage and conditions of
usage, consider replacing trailer tires even if they have tread
depth remaining.
– After five years, trailer tires should be replaced in all cases.
Review - Practices for Safe Trailer Tire Use
– Select the correct tires to match the application and
capacity requirements.
– Never use passenger car or truck tires for trailer use.
– Do not overload trailer tires, maximum loads are listed on the
sidewall of the tire.
– Maintain air pressure at the maximum PSI recommended on the
tire sidewall.
– Check tire pressure when tires are cold and in the shade.
– Use a cap on valve stems to prevent contamination of the internal
rubber valve.
– Always travel with a spare and check the spare air pressure along
with the other tires.
– Perform a visual inspection of trailer tires before each trip,
inspecting for cuts, bulges, punctures or signs of anything unusual.
– Inspect trailer wheels. If rims are bent or cracked, replacement or
repair may be necessary.
– Keep trailer tires in a cool dry place and out of direct sunlight
during storage.
– Use tire covers to protect tires from the harsh effects of direct
sunlight, moisture and temperature extremes.
– During extended storage, use a thin piece of wood or other surface
barrier under tires to extend tire life. For seasonal or extreme long
term storage, elevate the trailer on blocks to take the weight off the
tires. Reduce the air pressure and cover the tires to protect them
from direct sunlight.
– Replace trailer tires every three to five years.
– If you experience a series of successive blowouts, something is
wrong with your setup, it is not a tire problem.
When it's replacement time, Carlisle offers a complete line of tires
designed for most towing applications. Whether your precious cargo
is your new bass boat, construction equipment or a family travel
trailer, enjoy long, safe travels using the correct tires,
properly inflated and within the designated
load capacity.
The Carlisle Radial TrailRH.
Tow with Trust
™.
Official Tire - American Bass Anglers Tour.
Trailer Tires:
Tips & Best Practices, Continued
carlisletransportationproducts.com
Trending Topics
#9
09-01-2014, 02:21 PM
#10
09-01-2014, 02:25 PM
Actually, that's a common misconception. RST is just the name and in no way is referring to an ST tire. G614's are LT tires as stated on their website. Goodyear even put out a bulletin explaining this but I'll be damned if I can remember where I saw it... They were originally designed for HD trucks like tow trucks and also approved for trailer use. Since these type trucks no longer run 16" rims Goodyear officially changed their "position" usage to trailer but their history is still hinted at with their LT designation.
#12
09-01-2014, 03:29 PM
#13
09-01-2014, 03:57 PM
#14
09-01-2014, 04:07 PM