8529IKBS Tires

[jlrupert909]

I'm down to two Castle Rock E rated tires. They are max load rated at 2830 lbs. They say 117L on the sides which I think means a higher speed rating as well, perhaps 85 mph.

Looking for 4 replacement tires, this is what I think I need but thought I'd bounce this off the members to make sure my calculations are close before I spend the money.

Dry weight + Max Cargo weight - Tongue Weight = Weight that all tires need to support as a team.

My Flagstaff 8529IKBS = 9434 + 2089 – 1581 = 9,942 lbs or let’s just say 10,000 lbs which is 1% over calc. Ironically the axles are rated at 5,000 lbs and there are two. Flagstaff, why not give us 6,000 lb axles? Geez

10,000 / 4 = 2,500 lbs per tire with 0% head room (well 1% because I rounded up).

Add 10% you get 11,000 / 4 = 2,750. Is 10% good enough?

Our trailer is tall and the wind plays havoc so I suspect this puts side load on these tires and truthfully I sometimes drive over 65 mph so I randomly speed stress these tires.

My conclusion is these tires (Castle Rock "E") are rated higher than they are capable and my personal feeling is they are unreliable. So the original tires are at the cusp of their ability IMHO.

I'm thinking of switching to 4 GOODYEAR ENDURANCE all Season Radial Tire-ST225/75R15 E/10 117N

But should I be looking at something with a higher rating? I'm so tired of blow-outs that take out the side of my trailer.

Thanks in advance for your advice

Oh, before I forget. 2018 Flagstaff, model 8529IKBS 5th wheel, pulled by a 2013 GMC Denali 2500 HD.

[JohnD10]

Don't buy four Goodyear Endurance tires...buy five!

If you don't trust the Castle Rocks...do you really want to keep one as a spare tire?

[babock]

Agreed. When I replaced the castle rocks, bought 5 tires.

[jlrupert909]

In all the first time fun, excitement and panic of what to do when you're along side the road (and while not realizing tire ratings matter), I do have one "Power King Tow-Max" ratings are 117L/112L, E, Max Load: 2860, 10 ply which is relatively new (bought Sept. 2018).

1) I was planning on using it (tow-Max) for a spare or should I spring for all 5 GY's as recommended?

2) Sounds like there is no thoughts that I should go with bigger / higher rated tires than "E" correct?

[JohnD10]

TowMax tires are also known as 'BlowMax' tires for a reason...

[jlrupert909]

oh that's not good. I looked a review and found "Cons .. Numerous issues with blowouts and failures from other trailer owners"

Thanks for the inspiration otherwise I would NOT have checked.

Looks like I'd better get 5 GY's just so I can sleep better until my next blowout.

[5picker]

I have your exact same 5th wheel. We had the Castle Rocks (and had issues) and I replaced all 5 (including spare) with Goodyear Endurance LRE about 18 months ago.

Tows better, handles better, feels better.

[Airdale]

Originally Posted by jlrupert909

I'm down to two Castle Rock E rated tires. They are max load rated at 2830 lbs. They say 117L on the sides which I think means a higher speed rating as well, perhaps 85 mph.

Speed letter L=75 MPH

Looking for 4 replacement tires, this is what I think I need but thought I'd bounce this off the members to make sure my calculations are close before I spend the money.

Dry weight + Max Cargo weight - Tongue Weight = Weight that all tires need to support as a team.

My Flagstaff 8529IKBS = 9434 + 2089 – 1581 = 9,942 lbs or let’s just say 10,000 lbs which is 1% over calc. Ironically the axles are rated at 5,000 lbs and there are two. Flagstaff, why not give us 6,000 lb axles? Geez

This may sound a little crude but the trailer was built to a target value, nothing more. If you need to exceed that value you got the wrong trailer. 6000# axles would go on a trailer 2000# heavier than yours.

10,000 / 4 = 2,500 lbs per tire with 0% head room (well 1% because I rounded up).

Add 10% you get 11,000 / 4 = 2,750. Is 10% good enough?

Our trailer is tall and the wind plays havoc so I suspect this puts side load on these tires and truthfully I sometimes drive over 65 mph so I randomly speed stress these tires.

My conclusion is these tires (Castle Rock "E") are rated higher than they are capable and my personal feeling is they are unreliable. So the original tires are at the cusp of their ability IMHO.

I'm thinking of switching to 4 GOODYEAR ENDURANCE all Season Radial Tire-ST225/75R15 E/10 117N

But should I be looking at something with a higher rating? I'm so tired of blow-outs that take out the side of my trailer.

Thanks in advance for your advice

Oh, before I forget. 2018 Flagstaff, model 8529IKBS 5th wheel, pulled by a 2013 GMC Denali 2500 HD.

I recommend you find some scales and find out how much weight is on your axles. Your current tires are providing more than 15% in load capacity reserves when properly serviced. They should not be failing. Maybe you have an alignment problem or something else in the chasse causing early tire failures. You'll want to find the problem before you put new rubber on there.

[NMWildcat]

Some folks love their Castle Rocks, but it seems far more experience problems with them. Our friends who had Castle Rocks (and a 10k dry/11.5k loaded fiver) had multiple blowouts on their year old tires before replacing them with Maxxis M8008. No more blowouts for the past four years for them. So the folks that told them it had to be a problem with pressure, alignment, or load, were just wrong.
I don't think you can go wrong with Endurance or Maxxis for an ST tire. For your weights, load range E should be perfect.

[jlrupert909]

Per advice found here on this forum, I replaced all 5 tires with Goodyears. I leave tomorrow on a long RV adventure so plan to post how things go. I also bought the TSTTruck tire monitor system to keep tabs on these new tires. The TST system took awhile for me to setup mainly because I think I'm so smart that I don't have to read directions. Ultimately, I did and got it all working. But not sure about accuracy yet so will let you know how things go. My tires are set at 80 but they report 77 so it is within their margin of error.

Also, putting some of the weight in the bed of the truck.