If you now give weights, I will calculate a highest pressure without bumping for you.
Need next.
Howmany axles and wheels( on the ground when driving, so not spare- and nose-wheel )
Best: weighed seperate wheelloads in the loading you drive.
Second best : seperate axle-loads ( if tandem-axle)
Third best: all axles together weighed.
But if not weighed, we will have to do with GVWR and GAWR's.
Tires did not change in specifications, old where same sise and D-load ( you used 60 psi, so no C- load AT 50 psi).
I feel vindicated for refusing to take a trip with the trailer until the tires were replaced! Our Cougar came with Trailer King tires. They made me nervous even though the RV repair shop inspected them and said they were ok. After 15 months sitting in storage I wasn’t so sure. My husband ordered new Goodyear Endurance tires on line and a mobile tire service installed them at the storage site. I’m ever so much happier! Now I have to deal with 15 months of grit and dust before we leave for a short trip in a couple of days.
I have TK tires on my 2021 Cougar. There is a dedicated group on Facebook that has discussed these tires to death. I understand that the early TK RST tires were comparable to Goodyear Marathons which had similar problems. Then the company that makes the TK tires did a redesign sometime in early 2019 that cured several issues. Checking the date code on my tires, they were manufactured around early-mid November of 2019 meaning they are the newer design. The speed rating on the tires is M, meaning they are rated for about 80 MPH. With all that said, I decided, for my piece of mine, to add a Tire Minder TPMS system. I inspect my tires before each trip and check my tire pressure on a regular basis. So far, we've ridden approximately 1500 miles since new. We expect to do another 2000 miles or so this year.
Most GY Endurance carry a speed ratting of “N” which is 87MPH and a prime reason they last longer. Speed (heat build up) kills trailer tires.
Even Tireman9 writes that ST tires are given maxload for 65mph.
I once found out the system the tiremakers use for that, is rule of tumb 1 loadindexstep different for every 10kmph/6.5mph different.
Higher speed/ lower Loadindex.
Lower speed / higher loadindex.
Used this to lower ST by 6 LI steps, to get the deflection a LT 99mph tire would have.
But lately I discovered that classic smaller sises did not upgrade by 6 steps, so are not needed to degrade with my system.
The 205/75R14 here mentioned is one of them.
But the 235/80 and 85 R 16 , for now use my 6 LI steps higher then LT 99mph maxspeed.
The smaller sises in the old list I give sometimes only 2 steps degradation needed, but the bigger sises need 6 LI steps.
That no tirefailure with Endurance, is because together with the Endurance, mostly also a loadrange upgrade, and adviced maximum pressure of that is used.
DB, your "Most GY Endurance carry a speed ratting of “N” which is 87MPH and a prime reason they last longer" could use a little backup. Maybe along the lines of them lasting longer....some figures, a reference or two?
__________________
Jim in Memphis, Wife of 51 years is Brenda
2019 F450 6.7 Powerstroke
2018 Mobile Suites 40RSSA
2021 40' Jayco Eagle
2001 Road king w/matching Harley sidecar
2021 Yamaha X2 Wolverine 1000
Replaced the Westlakes on our 2017 Cougar 21rbs Xlite couple weeks ago. Probably had 7 or 8 K on them, looked fine, lots of tread even wear. Nope. Goodbye. Got Goodyear Endurance ST225/75R15 at Tire Rack, picked them up at local distribution center 30 minutes away, had my buddy who owns a small shop mount and spin balance them. Feel much better now.
2018 Outback 330 RL.Traveling from Texas to Virginia. On I-40 West Memphis. Stopped in traffic - construction. Noticed bulge out my rear view. Got out to check, big bubble. Still had air in tire. Soon as I moved bubble popped. Proceeded to next exit, Walmart parking lot. Anyhow 4 hrs. later Roadside Asst. shows up. 3yrs.on Trailer King tires. Replaced with Carlisle Radial Trail HD E rated. Soon to replace all tires before moving again.
I have a 2018 2520RL Keystone Passport. It has Trailer King tires, ST205 75R 14. April 27, 2021 noticed the tread bulging on one of the tires. I checked the air pressure and it read only 31.5 lbs. I put 60 PSI in them before traveling 165 miles. We were at a FL state park and called roadside service that put on our spare. Took the tire to a Goodyear store and got the Endurance, same size load range D. Last year I put an Endurance on the other side of the same axle because it got a nail in it in a spot that it couldn't be repaired. I plan on replacing the other two Trailer King tires with Goodyear Endurance this week. I have no trust in Trailer King tires. They were manufactured the 20th week of 2017. So they lasted 4 years on the trailer.
If you still have the "bulging" tire get a couple pictures.
File a complaint with NHTSA and include the tire DOT and trailer VIN
__________________
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.
Very similar to my experience with TK's... Only in my "belt separation" there was no way to see any of the problems from the outside... only when the tires were removed from the wheels and you could see inside was the damage visible...
Yes the tire has Belt Separation. NHTSA would like those pictures. BUT have you confirmed why the tire was loosing air? Are the valves OK/ Are they metal bolt-in?
__________________
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.
The pix I posted in #24 is not the best, & I looked in the sidewall pix but only size & load range E showed. Turns out my 2029 cougar 24sabwe was built 4/21/2019. Hmmm.
That means the Tires were pre 2019 rededign & I have since replaced them all. We now have 20k miles on the new Suilam (sp?) & tread ware is zip compared to the 9k on the TK's. There were no tread swipes left but wear bars weren't showing yet on the 4 TK grounders.
It's basically like choosing one's TV, pick your's & unless or untill disaster happens, we'll fight for our choices.
__________________
Mot
Love our Cougar full time
TT 2020 Cougar 24sabwe 38,000 miles, TV 2004 chevy 2500 HD 4x4 287,000 miles.
We walked past the spare tire & this is what the TK had done over night.
It had never been on the road.
We picked the rig up in May, traveled 9k miles w/o problems but replaced this, then all 4 groundlings with Suiluns.
Get rid of any TK's asap.
Be sure to file a complaint with NHTSA. You will need tire DOT and RV VIN.
__________________
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.
Yes the tire has Belt Separation. NHTSA would like those pictures. BUT have you confirmed why the tire was loosing air? Are the valves OK/ Are they metal bolt-in?
Those tires were installed as OEM on our 2014 Cougar XLite. We bought the trailer in May 2013, so they were probably manufactured sometime in the first half of 2013. The valve stems, if I remember, were metal with a rubber coating and "pulled into the wheels" like most rubber valve stems. They were not "all rubber" and they were not "all metal/nut clamp" type valve stems. The tires are "long gone to a recycle plant and are probably either rubber mulch or mudflaps by now.... As best I recall, they weren't losing air. At the most, I may have aired them up 2 or 3 PSI before each trip when I checked all the tires before departure. I don't ever recall any "major air loss".
Honestly, I don't even have any record (that I know of) to indicate the tire DOT or even the MFG date/lot numbers. Other than the outer tire casing photo, I have no "proof that they are Trailer King" tires or that the inside is the same tire as the outside...
Smart move getting rid of the tires. I am surprised that they lasted that long. The original tires on our 2018 Springdale (Sterling Sport tires) lasted less than 2,000 miles. Blowouts on a busy highway are not fun. We replaced them with Carlyle HD tires which are not only safer, but also the improved the towing experience. I also recommend upgrading the suspension, as well. We upgraded to MoRryde equalizers with heavy duty shackle straps, wet bolts, and brass bushings. Keystone totally cheaps out with their tires and suspensions.
Be sure to file a complaint with NHTSA. You will need tire DOT and RV VIN.
I think the above process is unrealistic for regular folks...sitting on the side of the road with a blowout on the RV, wheel well and side in shreds, 100 degrees outside fighting with all the tools to get the blasted failed tire off. Once replaced and the failed tire in the bed of the truck the last, very last, thing I want to do is start documenting the failure, taking pics and writing down info, so I can send it to a government agency that will not do a thing about it....in my lifetime - while I'm sweating, dirty and 2 hours behind schedule. Naw, all I want to do is set fire to the offending tire and replace them all with new ones....but that's just me.
__________________
Danny and Susan, wife of 56 years
2019 Ram 3500 Laramie CC SWB SB 6.4 4x4 4.10
2020 Montana High Country 331RL
Those tires were installed as OEM on our 2014 Cougar XLite. We bought the trailer in May 2013, so they were probably manufactured sometime in the first half of 2013. The valve stems, if I remember, were metal with a rubber coating and "pulled into the wheels" like most rubber valve stems. They were not "all rubber" and they were not "all metal/nut clamp" type valve stems. The tires are "long gone to a recycle plant and are probably either rubber mulch or mudflaps by now.... As best I recall, they weren't losing air. At the most, I may have aired them up 2 or 3 PSI before each trip when I checked all the tires before departure. I don't ever recall any "major air loss".
Honestly, I don't even have any record (that I know of) to indicate the tire DOT or even the MFG date/lot numbers. Other than the outer tire casing photo, I have no "proof that they are Trailer King" tires or that the inside is the same tire as the outside...
Thanks for the reply. A comment...... Everyone should have a written record of the DOT serial for each tire. This could save the cost of a tire if there is a recall. Keep the serial record with your other reference paperwork.
__________________
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.
This website is not affiliated with or endorsed by the Keystone RV Company or any of its affiliates in any way. Keystone RV® is a registered trademark of the Keystone RV Company.
)
Linear Mode
