Again with tires - load rating on a heavy 5th wheel

[fredcrowley]

I have a 43 foot 5th wheel FR Sierra with tandem axles (not a Toy Hauler). We are full-timers putting maybe 15,000 miles per year on the rig. The axles are Dexter 7000#. The rig’s GVWR is 15,800#, and the hitch weight is 2900# weighed on CAT scales. Theoretically this gives me 12,900# to be carried by the RV tires. I haul it with an F350 dually diesel, with some suspension mods to handle the hitch weight.

I have been running with Goodyear Marathons ST235/80R16 load range E that are rated at 3420# @ 80psi. 3420# x 4 = 13,680#. 13,680# - 12,900# = 780# safety margin. This seems to be cutting it a bit close!

I rigorously check the tire pressures cold @ 80 psi, and use a TPMS system monitoring psi and tire temps. The road speed never exceeds 62-63 mph (even downhill). Yet despite this, I have had 2 blowouts with the Marathons within the past 3 months. Tire age is about 2 years, with my road usage about 8 months. The only good news is that I have become very adept at repairing wiring damage and aluminum skirt body damage. I do not need to add to my experience, thus I am looking for something more reliable. Additional to avoid having to call upon my repair skills, I am not worried about the cost factor of better(!) tires.

The RV forums seem to favor either Michelin XPS Rib LT235/85 R16 rated @ 3086#, or Maxxi ST 235/80R16 rated @ 3420#. I know the difference between LT and ST designations

The LT Michelins seem to get a real positive rating by users, but I have concerns about the Max Load rating.

Looking at the Forum discussions, they seem to be referring to 5th wheels that are significantly lighter than mine.

In talking with eTrailer they were suggesting either:

Taskmaster ST235/85R16 Radial Trailer Tire - Load Range G, 14 ply with a load rating of 4,080# at 110 psi. The numbers seem fine, but I've never heard of this brand. Chinese?

or

Westlake ST235/85R16 - Load range G, 14 ply and a 4,080# maximum load at 110 psi. The numbers again seem fine, but I'm pretty sure Westlake IS made in China.

Finally my questions:

1. Will the Michelins handle the weight of my rig? 4x 3086 = 12,344# tire load rating to carry 12,900# rig weight on the tires. In theory, I'd say no.

2. The Maxxis have the same numbers as the Marathons, and by calculation carrying 12,900# on a max combined load rating of 13,680#.

3. Both the Taskmaster and Westlake numbers seem fine, but obviously I’m real concerned about Chinese made tires! Has anyone had any experience with these tires, especially with G load ratings


Comments, opinions??

Thanks Fred

[CaptnJohn]

Originally Posted by fredcrowley

I have a 43 foot 5th wheel FR Sierra with tandem axles (not a Toy Hauler). We are full-timers putting maybe 15,000 miles per year on the rig. The axles are Dexter 7000#. The rig’s GVWR is 15,800#, and the hitch weight is 2900# weighed on CAT scales. Theoretically this gives me 12,900# to be carried by the RV tires. I haul it with an F350 dually diesel, with some suspension mods to handle the hitch weight.

I have been running with Goodyear Marathons ST235/80R16 load range E that are rated at 3420# @ 80psi. 3420# x 4 = 13,680#. 13,680# - 12,900# = 780# safety margin. This seems to be cutting it a bit close!

I rigorously check the tire pressures cold @ 80 psi, and use a TPMS system monitoring psi and tire temps. The road speed never exceeds 62-63 mph (even downhill). Yet despite this, I have had 2 blowouts with the Marathons within the past 3 months. Tire age is about 2 years, with my road usage about 8 months. The only good news is that I have become very adept at repairing wiring damage and aluminum skirt body damage. I do not need to add to my experience, thus I am looking for something more reliable. Additional to avoid having to call upon my repair skills, I am not worried about the cost factor of better(!) tires.

The RV forums seem to favor either Michelin XPS Rib LT235/85 R16 rated @ 3086#, or Maxxi ST 235/80R16 rated @ 3420#. I know the difference between LT and ST designations

The LT Michelins seem to get a real positive rating by users, but I have concerns about the Max Load rating.

Looking at the Forum discussions, they seem to be referring to 5th wheels that are significantly lighter than mine.

In talking with eTrailer they were suggesting either:

Taskmaster ST235/85R16 Radial Trailer Tire - Load Range G, 14 ply with a load rating of 4,080# at 110 psi. The numbers seem fine, but I've never heard of this brand. Chinese?

or

Westlake ST235/85R16 - Load range G, 14 ply and a 4,080# maximum load at 110 psi. The numbers again seem fine, but I'm pretty sure Westlake IS made in China.

Finally my questions:

1. Will the Michelins handle the weight of my rig? 4x 3086 = 12,344# tire load rating to carry 12,900# rig weight on the tires. In theory, I'd say no.

2. The Maxxis have the same numbers as the Marathons, and by calculation carrying 12,900# on a max combined load rating of 13,680#.

3. Both the Taskmaster and Westlake numbers seem fine, but obviously I’m real concerned about Chinese made tires! Has anyone had any experience with these tires, especially with G load ratings


Comments, opinions??

Thanks Fred

1st ~~ many will disagree but your rims may not be rated to hold 110# even if stamped for the weight. Was informed of that by the maker of my rims.
2nd ~~ A tire engineer suggested Carlisle tires. They have a good reputation for several reasons. Not only in your current size and a G rated but a 235/85R16 LR F requires 95#. See more here:
During a visit to China in April 2015, Van Ormer saw many new lines of ST products, but says he is aware of only one manufacturer that has “truly changed” the technology of the ST tires. That manufacturer is Carlstar Group LLC, formerly CTP Transportation Products and before that, Carlisle Transportation Products. “With the RH (radial) and LH (bias) trailer tires, they beefed up the bead and sidewall packages so that few others can compete quality-wise with them,” Van Ormer says.

http://www.moderntiredealer.com/article/312514/st-tires-all-steel-radial-construction-is-meeting-the-demand-for-more-carrying-capacity


I spoke to other owners of Carlisle and all were pleased. My tire dealer said he can get any Carlisle tire for any of his 4 locations in 1 day. Maxxis take 3 - 5 business days.

[emm-dee]

Just get the Goodyear G614, 3,750 pound rating. Made in Alabama.

[ependydad]

At your weight and miles per year, I wouldn't be looking at ST tires any longer.

As emm-dee said, you want a minimum of Goodyear G614 or Sailun S635. They're very similar -
Goodyear has the name brand; Sailun has a cheaper price. Both get excellent reviews. As CaptnDan mentioned, the rims could be an issue.

OR- you could go nuts and opt for 17.5" rims and commercial trailer tires. You'll jump up to load range H or J tires, get a higher speed rating, and get durable tires as a result. It's what I did since I was fulltiming and running about 16,000 lbs. on two 7,000 lbs. axles.

More info about tire choices:
http://learntorv.com/what-are-the-be...-your-trailer/

More info on the 17.5" upgrade:
http://learntorv.com/major-tire-whee...er-overloaded/

[kayo]

Get rid of those Marthon's as soon as you can!!! I lost three out of four in 6 days last fall with only 14000 miles on them.As others noted above, I too went with )the Goodyar ST235 tires and have them at 100 # (my rims will take 110#) I only witht hedealer had suggested/insisted on getting me to buy tire pressure sensors!

[Havasu Bill]

I went with the G614's when I only had 500 or so miles on the Marathons. Just the peace of mind made it well worth it.
I also added a TPMS system as well.

[Taranwanderer]

Originally Posted by ependydad

At your weight and miles per year, I wouldn't be looking at ST tires any longer.

As emm-dee said, you want a minimum of Goodyear G614 or Sailun S635. They're very similar -
Goodyear has the name brand; Sailun has a cheaper price. Both get excellent reviews. As CaptnDan mentioned, the rims could be an issue.

OR- you could go nuts and opt for 17.5" rims and commercial trailer tires. You'll jump up to load range H or J tires, get a higher speed rating, and get durable tires as a result. It's what I did since I was fulltiming and running about 16,000 lbs. on two 7,000 lbs. axles.

More info about tire choices:
What are the best tires for your trailer? | Learn To RV

More info on the 17.5" upgrade:
Major tire & wheel upgrade – no longer overloaded | Learn To RV

The 17.5" upgrade is nice but I don't see it as an option if you have 6-lug axles and wheels...or maybe I'm just missing it.???

[ependydad]

Originally Posted by Taranwanderer

The 17.5" upgrade is nice but I don't see it as an option if you have 6-lug axles and wheels...or maybe I'm just missing it.???

You're right. But the OP said they're on 7,000 lbs. axles which I thought were all 8-lug wheels; of course, I could be wrong.

But for 6-lug wheels, you're definitely right- the 17.5" rims aren't an option.

[donniedu]

You want to really be safe? Invest in new 17.5 inch tires and wheels. You can purchase them online from several retailers at a decent price. Generally the tires will be rated at 4000+ pounds each giving tou a good safety margain and readily accesavle product choices.

[GOTTOYS]

I got a recent quote for 17.5 Sailun tires on aluminum wheels including lugs, center caps and shipping at $1400.00 all in. They are Chinese made tires but have an excellent reputation around the internet...This is an H rated tire and the tire diameter is the same same as most of the 235/80/16s that everybody is using.

[Airdale]

Originally Posted by fredcrowley

I have a 43 foot 5th wheel FR Sierra with tandem axles (not a Toy Hauler). We are full-timers putting maybe 15,000 miles per year on the rig. The axles are Dexter 7000#. The rig’s GVWR is 15,800#, and the hitch weight is 2900# weighed on CAT scales. Theoretically this gives me 12,900# to be carried by the RV tires. I haul it with an F350 dually diesel, with some suspension mods to handle the hitch weight.

Your trailer's certification label lists the manufacturer's GAWR limit. Sometimes it's lower than the axle manufacturer's limit. If the Marathons are Original Equipment tires the GAWR for your axles may be something around 6750# each. The marathons do not legally qualify as OEM for 7000# GAWR axles.

I have been running with Goodyear Marathons ST235/80R16 load range E that are rated at 3420# @ 80psi. 3420# x 4 = 13,680#. 13,680# - 12,900# = 780# safety margin. This seems to be cutting it a bit close!

I rigorously check the tire pressures cold @ 80 psi, and use a TPMS system monitoring psi and tire temps. The road speed never exceeds 62-63 mph (even downhill). Yet despite this, I have had 2 blowouts with the Marathons within the past 3 months. Tire age is about 2 years, with my road usage about 8 months. The only good news is that I have become very adept at repairing wiring damage and aluminum skirt body damage. I do not need to add to my experience, thus I am looking for something more reliable. Additional to avoid having to call upon my repair skills, I am not worried about the cost factor of better(!) tires.

The RV forums seem to favor either Michelin XPS Rib LT235/85 R16 rated @ 3086#, or Maxxi ST 235/80R16 rated @ 3420#. I know the difference between LT and ST designations

The LT Michelins seem to get a real positive rating by users, but I have concerns about the Max Load rating.

The LT235/85R16E Michelin's or any of their other 16" tires do not qualify for fitment on your axles...not enough load capacity.

Looking at the Forum discussions, they seem to be referring to 5th wheels that are significantly lighter than mine.

In talking with eTrailer they were suggesting either:

Taskmaster ST235/85R16 Radial Trailer Tire - Load Range G, 14 ply with a load rating of 4,080# at 110 psi. The numbers seem fine, but I've never heard of this brand. Chinese?

or

Westlake ST235/85R16 - Load range G, 14 ply and a 4,080# maximum load at 110 psi. The numbers again seem fine, but I'm pretty sure Westlake IS made in China.

You should check your current rim specs. Most OEM rims for ST230/80R16E OE tire fitments are 16x6J, rated at 3580# with a psi rating of 80 PSI. Sometimes with a rig your size the OEM rims will be 16x6J rated at 3960# with a psi rating of 110 PSI. Those rims do not qualify for any of the LRG (LT or ST) tires because they require a 6.5" rim width. However they do qualify for the ST235/85R16F with a load capacity of 3960# at 95 PSI.

Finally my questions:

1. Will the Michelins handle the weight of my rig? 4x 3086 = 12,344# tire load rating to carry 12,900# rig weight on the tires. In theory, I'd say no.

2. The Maxxis have the same numbers as the Marathons, and by calculation carrying 12,900# on a max combined load rating of 13,680#.

3. Both the Taskmaster and Westlake numbers seem fine, but obviously I’m real concerned about Chinese made tires! Has anyone had any experience with these tires, especially with G load ratings


The Westlake tires are OEM on a number of FR heavier trailers. You can do a forum search for them to read any feedback.

Comments, opinions??

Thanks Fred

See notes above in green.

Note; It's important to remember that Original Equipment tires are fitted to the trailer manufacturer's GAWR for that unit, not the axle manufacturers limit. It's a safety violation for the vehicle manufacturer if the OE tires do not provide the load capacity to support the GAWR.

[fredcrowley]

I would to thank everyone for the input.

What I elected to do was to upgrade to 17.5" rims (the hubs are 8 bolt). I ordered a complete set of tires and rims from Tires and Wheels, Inc.

Specifically I ordered Goodyear G114 215/75R17.5 Load Range H mounted on a spiffy set of aluminum rims. The G114s have a rated capacity of 4850#.

There are several sources available, but I chose Tires and Wheel, Inc., as they offered a discount coupon, and were able to ship immediately. Placed the order on Saturday evening. By Monday morning (today), I had confirmation that they have shipped. All-in cost was $2300 for 4 (sucked wind a bit!), but they are already mounted, balanced, with new lug nuts, and free shipping. See attached pic for an image.

[donniedu]

I doubt you will be unhappy with the decision. Congratulations.

[emm-dee]

Four GY614 on new wheels, ready to put on the trailer for $2,300 sounds like a fair price.

[ependydad]

Originally Posted by emm-dee

Four GY614 on new wheels, ready to put on the trailer for $2,300 sounds like a fair price.

Not G614, G114.

Originally Posted by fredcrowley

I would to thank everyone for the input.

What I elected to do was to upgrade to 17.5" rims (the hubs are 8 bolt). I ordered a complete set of tires and rims from Tires and Wheels, Inc.

Specifically I ordered Goodyear G114 215/75R17.5 Load Range H mounted on a spiffy set of aluminum rims. The G114s have a rated capacity of 4850#.

There are several sources available, but I chose Tires and Wheel, Inc., as they offered a discount coupon, and were able to ship immediately. Placed the order on Saturday evening. By Monday morning (today), I had confirmation that they have shipped. All-in cost was $2300 for 4 (sucked wind a bit!), but they are already mounted, balanced, with new lug nuts, and free shipping. See attached pic for an image.

Sounds great! That's who I bought from as well. They also saved me some money over another vendor.

[emm-dee]

Originally Posted by ependydad

Not G614, G114.

Even better deal since the 114s are usually 60-80 buck higher than the 614.