TOWMAX Got me; Need clarification !!!!!!

[PARAPTOR]

Have issue with Towmax tires, coming apart and need new tires. Here is my confusion at the moment . Was/Have ordered MAXXIS TIRES ST235/80R 10PR TL M8008 ST RADIAL tires based on forum recommendations, then when I checked this morning I found the weight rating on these is only 3420 lbs versus the towmax and other brands 80 series 10 ply which all seem to be over 3500 lbs . Have members used these on 7000 lb axles?? CONFUSED and NEED some clarification

[JRTJH]

There are a couple of threads concerning using tires rated UNDER the axle rating. I think, if I recall correctly, the recommendation was "don't do it". Reasoning for that is the requirement to maintain tires on the trailer "equal to or greater than" the tire placard attached.

Realistically, my thought would be that "IF" the axle is rated at 7000 lbs, then tires rated greater than 3500 lbs each would be required. If, however, the axle is rated at 7000 lbs and the weight on that axle was never greater than 6500 lbs, then using tires rated at 3420 would "work" but not meet compliance with the sticker. ????

What to do? What to do? If it were mine, and I were buying new tires, I'd look at the investment in money. If installing "too small" tires is $700 and installing "correct size" tires is $800, it would be my choice to install the correct tires now rather than risk having to pay twice for the same thing.... Should the "too small" tires not work...........

With all the concern about not overloading tires, I wouldn't install anything that is "smaller than recommended" either is size or in load rating.

What does the weight/tire placard on your trailer require for tire size/rating?

[Dave-Gray]

If you haven't weighed your trailer, how do you know what you need? How do you know that the current tires are not overloaded and/or under inflated? Tires usually blow out as a result of an overloaded RV, improper inflation or excessively worn tread.

The folks at the Good Sam Vehicle Insurance Program state that tire failure is the cause of 60% to 70% of all Good Sam VIP comprehensive claims. Good Sam VIP

[PARAPTOR]

Originally Posted by JRTJH

There are a couple of threads concerning using tires rated UNDER the axle rating. I think, if I recall correctly, the recommendation was "don't do it". Reasoning for that is the requirement to maintain tires on the trailer "equal to or greater than" the tire placard attached.

Realistically, my thought would be that "IF" the axle is rated at 7000 lbs, then tires rated greater than 3500 lbs each would be required. If, however, the axle is rated at 7000 lbs and the weight on that axle was never greater than 6500 lbs, then using tires rated at 3420 would "work" but not meet compliance with the sticker. ????

What to do? What to do? If it were mine, and I were buying new tires, I'd look at the investment in money. If installing "too small" tires is $700 and installing "correct size" tires is $800, it would be my choice to install the correct tires now rather than risk having to pay twice for the same thing.... Should the "too small" tires not work...........

With all the concern about not overloading tires, I wouldn't install anything that is "smaller than recommended" either is size or in load rating.

What does the weight/tire placard on your trailer require for tire size/rating?

Here is my dilemma placard on Raptor only states st235/80R16 E 80PSI. Original TOWMAX on there ST235/80F16 E as I looked them up they were 3520 lbs max weight. Talked to a few tire shops that looked up that size E rated and said they all were around 3520lbs except MAXXIS M8008.

Called Maxxis and talked to someone who claimed that according to tire standards an E rated tires can not be rated more than 3420??? and said he was not sure how other companies can rate them any higher??

As far as number The RAPTOR has 7000 lb tandem axles its GVWR 16,500 lbs. For fun I have been using max 22% pin for these RAPTORS so at GVWR pin would be around 3630 leaving 12870 on the axles. Going from I think the lowest pin weight of 3000 lbs leaves 13500 0n the axles.

So we have a range of 12870 to 13500 on the tandem axles, or 6435 to 6750 lbs per axle. which comes out to be 3218 to 3375 lbs on each tire

Looks like for some reason any E rated 235/80R16 tire except MAXXIS M8008 will be rated over 3500 lbs max

Hope I clarified further my dilemma. Any further comments will be appreciated. Next step up would be an 85 tire versus 80

EDIT example Carlisle Radial Trail ST 235/80R16 E 3520 lbs

[CWtheMan]

I'm pretty sure you will find that your 7000# axles were de-rated by Keystone to 6750# each. It's one of the few ways they get around using the ST235/80R16E tires for fitment without violating FMVSS regulations. Look on your trailer's certification label to confirm the certified GAWR.

ST235/80R16E tires are manufactured with three different and certified load capacities. 3420#, 3500# and 3520#, all at 80 psi. Without load capacity justification on the individual trailer's certification label and in it's owner's manual all three load capacities default to the lowest of the three values. Therefore, the 3420# tires are just as qualified as replacements as the 3520# tires are.

It's a catch 22 that may be rectified when older molds and methods used by Goodyear, Maxxis and others using the lower load capacity values are brought up to date.

CW

[PARAPTOR]

Thanks CW...., was just about to PM you. My Raptor certification label states 7000 lb axles. Need to read your post one more time to see if I am following you on the different weight classifications on different brands for a ST235/80 R16 E. Having a bad day tire classification, trail-Aid Plus, and RAIN

[CWtheMan]

With a certification label depicting GAWR of 7000# fitted with ST235/80R16E tires there must be documentation from Keystone authorizing the use of those tires with 3500# or 3520# load capacities. If not, Keystone is in violation of FMVSS regulations and must provide you with a new certification label showing the correct tire size/GAWR. It will most likely require Keystone to perform a recall on all models with that false information on the certification labels.

You should call them and let them make the decision. If NHTSA makes them do it they may have to recall all certification labels having the possibility of depicting 7000# axles erroneously.

When doing the math on your trailer's specs there is room for 6800# GAWR axles. That will work.

CW

[PARAPTOR]

Thanks everyone! Done !! After playing with this all Day, and learning how these number were played with decided on the Carlisle Radial Trail RH ST235/85 R16 F (12 PLY) 3960 lbs max. @95 PSI Tires. So that I do not feel overconfident I am keeping a TOWMAX aka China BOMB as my spare These actually turned out to be less cost that the MAXXIS M8008 Actually an overkill since my rims are rated at only 3750 at 110PSI. OH well if I ever go back to a 2500 I could use them to increase the truck GVRW

[sw342]

Thats a 2 axle hauler right? Go Sailun S637. They will fit. Wouldn't waste my time on ST tires.

[PARAPTOR]

Yes, Tandem Axles. I am sure I could have spent another few hours, days ....... looking but honestly had enough . Read many posts on tires and decided it was time to PICK ONE and move on.

In a rush to get tires and get up and running, never actually explained what happened. Unlike others I was extremely lucky. In Pa, our trailers like vehicles require an inspection each and every year checking such things as tires, brakes, suspension, bearings, etc.. Upon a successful inspection an inspection sticker is placed in the street side window. Like any anywhere there are "LICKEM STICKEM PLACES" but I choice to take it to my trusted dealer knowing the RAPTOR is going to be looked over thoroughly.

Got this call, inspection failed upon examination he discovered one of the China Bombs was about ready to relieve itself. As he showed me the tire I have to admit some of the things he found I would not have picked up on. At least he caught it and I learned a little more about what to look for.

We are scheduled to leave on a few month trip, so I had been debating switching out the tires. BUT in the back of my head thinking well maybe after I get back from this trip , I have my TIRE MINDER where I can monitor real time tire temperature and pressure. I monitor all 12 tires, amazing how we have a tendency to use things as a crutch

Now I feel comfortable and like I stated before if I need any excitement I still keep one china bomb as the spare

[audio1der]

Great thread! I am dealing with the same thing on a smaller scale with our 3220. The 3500lb axles and springs were woefully inadequate. The rear axle looked like a rainbow at all times, and all 4 springs were flat, with no arc.
After replacing with larger axles and springs, our tires which were matched to the inadequate gear are now the weak point.
I'm trying to figure out if changing up to a 215/75/14 which gives an extra 110lbs capacity per tire, or ordering expensive 8 ply/load range 'D' 205/75/14 which give an extra 280lbs capacity per tire are the better choice.
(We have nice 14" alloys which would be a shame to get rid of, and moving to a 15" tire requires larger spindles..)

[CWtheMan]

audio1der

Maybe you should start another thread, this one is used-up with the OP satisfied with his new tires. His situation was different from yours.

CW