Another Tire Question

[shakyjay]

Time for new tires. Currently have ST205/75/15C's. They are the originals and up til now have been fine however age is taking it's toll and sidewalls are cracking. Stopped at America's Tire. Seems they now are not stocking the Towmasters which was one of the tires I was considering. Instead they have gone back to stocking the Carlisles that supposedly have been redesigned. I have done some research and it appears the new RH does have some improvements. After much discussion with the salesman who actually said he is running the Carlisles on his 13,500 lb. fifth wheel. He recommended that if I have the clearance to go with a Carlisle ST225/75/15 E rated tire. Supposedly it should only require about an 1.25 inches more of clearance. So my options are just replace with original size and range in a ST205 or what my original intent was to go ST205 in a D range or go up to the ST225 in load range E. Price between the three is really not that much difference D range $50 more than C and ST225 $80 more than C. The other option I am considering is to have him order the Maxxis. Price for them in ST250/75/15C is about $100 more than the same Carlisle. He absolutely did not recommend Marathons and said he could order the Towmasters but really did not recommend them either.

So after all that I am simply looking for some input to help me decide which option would be the best. I do not tow full time. Actually now days the trailer sits more than it moves. What travels we do use it for are generally no more than a couple of hundred miles one way. Occasionally we may go a little further. I do not run heavy but would like a little cushion.

[Lowsuv]

nothing in the charts quoted indicates that the wheels are only rated for 65 psi.
the charts are indicating the maximum load rating of that particular size and load range tire and the psi that the tires must be inflated to to carry that weight .
to limit the upgrade in tire size and psi limits the safety that can be built in by using a Load Range D ( 65 psi ) or Load Range E ( 80 psi ) tire .
The Tire is the Weak Link in the weight rating carried .
The steel wheel is not weaker than the tire . The steel wheel can take considerably more psi than the tire can . That is the reality and it also is logical.
A TPMS system although a good idea is not as good as spending that same expense to upgrade the current tire to one with a higher load rating as shown on the sidewall .
Hundred of thousands of GM trucks have been shipped with 245/75R16 tires as factory equipment . My swag guess is that 25 % of those tires have been upgraded to a 265/75R16 tire at replacement time . The factory GM wheels are 6.5 inches wide . Although the 265/75 tire calls for a 7 inch to 9 inch wheel width there really are no problems due to a narrow rim width other than it is not optimum.
I have been using the 265 instead of the 245 on factory 6.5 " wheels since 1998 .
For the record i use 2 sets of wheels. My snow tires are on factory 6.5" GM aluminum wheels . My summer Michelin 265/75r16E are mounted on 8 inch wide Weld aluminum wheels. The truck handles better with the 8" wheel and the summer tires of course.
it is less safe to continue using the factory supplied tire rated for 1820 # than upgrading to a higher rated tire (say 2271# ) even though a higher psi is needed .
brand is far less important than the rated load capacity .
tire rack can be your friend .
check out the specs from their trailer tire tab and do some comparisons for yourself .
because the continental Vanco 2 tire is rated on the LT criteria rather than the ST criteria it is a 99 mph tire . i would consider that particular tire to be the class of the field for RV use . it is factory equipment on the mercedes sprinter vans and motorhomes .

here is the web link with the specs:

http://www.tirerack.com/tires/tires.jsp?tireMake=Continental&tireModel=Vanco+2&sidewall=Blackwall&partnum=27R5V2&tab=Specs

[LarryJM]

Chuck&Gail wrote:
I guess the manufacturer of the wheels on my last three trailers are also misinformed.

Current STEEL wheels on Keystone Outback rated for 2600#. Came with ST225/75R15 LR-D. Note LR-E specs 2830# for 80 psi in that size.

Steel(?) wheels on Thor Wanderer rated for 65 psi, 2150#. Came with ST205/75R15 LR-C.

Current STEEL wheels on Mirage rated for 50 psi, 1820#. Came with ST205/75R15 LR-C.

Everyone can do as they wish. I wish to not exceed published (or stamped) specs.

I agree and to blindly recommend otherwise is IMO foolish and dangerous.

[JIMNLIN]

Lowsuv wrote:
jimnlin is misinformed about steel wheels not being able to take 80 psi.
side bearing loads and the strength of the wheel being able to support a load are exponentially greater than tire pressure within a wheel .
further , when these rv or light truck wheels fail they do not do so catastophically .
rather they develop a crack at a "shoulder" and they fail because they can no longer maintain a constant pressure.

I never said a steel wheel wasn't rated at 80 psi. See my above post on different wheel pressure ratings.
I base my opinion on facts from the wheel makers and my personal and other operators experience of busted out or cracked steel wheel centers and split bead seat flanges from using the wrong capacity/pressure rated wheels and from and wheel dealers recommendations.

All steel wheels are stamped from different material thicknesses so one size don't fit all.

when these rv or light truck wheels fail they do not do so catastophically .

Busted/cracked wheel centers and busted valleys are not uncommon on LDTs out here in the real world. Now granted the vast majority of RV folks/persons don't carry max axle/wheel or tire loads so its possible that some could come to the erroneous conclusion that wheels don't fail or especially don't fail catastrophically. Wheels can and have failed from using the wrong capacity(s).

[Chuck_Gail]

I guess the manufacturer of the wheels on my last three trailers are also misinformed.

Current STEEL wheels on Keystone Outback rated for 2600#. Came with ST225/75R15 LR-D. Note LR-E specs 2830# for 80 psi in that size.

Steel(?) wheels on Thor Wanderer rated for 65 psi, 2150#. Came with ST205/75R15 LR-C.

Current STEEL wheels on Mirage rated for 50 psi, 1820#. Came with ST205/75R15 LR-C.

Everyone can do as they wish. I wish to not exceed published (or stamped) specs.

[Lowsuv]

jimnlin is misinformed about steel wheels not being able to take 80 psi.
side bearing loads and the strength of the wheel being able to support a load are exponentially greater than tire pressure within a wheel .
further , when these rv or light truck wheels fail they do not do so catastophically .
rather they develop a crack at a "shoulder" and they fail because they can no longer maintain a constant pressure.

[coolbreeze01]

Rim width is a limiting factor as is psi rating or weight rating. If you can't find any info on the side of your rims, it may be stamped, but under the tires. Dismount a tire and check. If you don't like the numbers, new rims and tires might be the answer. Good luck.

[ktmrfs]

Chuck&Gail wrote:
Several points. First, as said, what are your RIMS rated for? Rating usually stamped on rear, or in valley UNDER the tire. Putting LR-D on a LR-C rim is a THIRTY PERCENT OVERLOAD. Not what I call safe. Obviously LR-E is an even worse overload.

Second what is your current rim WIDTH? Most ST205/75R15's I've seen are mounted on 5 or 5.5" rim widths. Most ST225/75R15's seem to require a 6" minimum rim width. Again, be careful what you do.

I looked at going to 225's on my cargo trailer to replace the 205's. Looking stopped when I saw the rim width. Fine for 205's but definitely narrow than the min spec for 225's. So went with LRD 205's and checked the wheels which are rated for 65psi.

towmax's on my outback were fine, no issues,replaced them with Maxxis LRE when they were worn out. The lasted about 5K fewer miles than the Maxxis on my cargo trailer, but part of that could very well be the % of rated load they were run at.

IMHO the best thing you can do to minimize the chance of a blowout on a trailer, regardless of tires is to install a TPMS. From personal experience, you won't notice a tire going down from a slow leak on a trailer, unlike a car. Low pressure=overload=heat=blowout. In my case I caught both of them at a roadside stop, nail in the tire, but much longer and I would likely had a blowout. TPMS will at least give you a warning of slow presssure loss.

[JIMNLIN]

shakyjay wrote:
Chuck I had not thought about the rim width. You are right they are only 5". Looks like that could be a limiting factor. The rims do not have a visible weight or psi rating anywhere on them. If it is there it must be stamped on the inside which really does not help as that means I won't know until they take the tire off the rim. I don't think there should be a problem going from C to D or which is going from 50 to 65 psi. I can see where going to 80 psi with and E rating could be an issue.

Wheels like tires are pressure and capacity rated. Anyone/persons that says all 15" steel wheels are pressure rated to 80 psi has no business offering advise or tell others to ignore the wheel manufacturers pressure ratings. If your steel wheels have no pressure ratings then its time to contact the wheel manufacture. You sure don't want a split bead seat on the wheel. Just like the over pressured tire it can have a sudden loss of pressure. Even tire manufacturers warn to use the proper pressure and capacity wheel for the tire.

Dexstar has 15" steel wheels rated at 50-65-75 and 80 psi.

Chuck makes a good point on using the proper width wheel for a particular tire. Same goes for pressure and capacity as one size don't fit all. Lets be safe out here.

[shakyjay]

Chuck I had not thought about the rim width. You are right they are only 5". Looks like that could be a limiting factor. The rims do not have a visible weight or psi rating anywhere on them. If it is there it must be stamped on the inside which really does not help as that means I won't know until they take the tire off the rim. I don't think there should be a problem going from C to D or which is going from 50 to 65 psi. I can see where going to 80 psi with and E rating could be an issue.

[Lowsuv]

regarding the ability of the steel wheels being able to take 80 psi that has been addressed repeatedly on this forum .
there are a bunch of misinformed posters who believe that these wheels will not allow 80 psi .
that myth has been debunked at length by the most knowledgable tire guys on this forum such as capri racer , fast eagle , and others .
the original steel wheels will take 80 psi with ease .
regarding upgrading your tires it is more important to increase the load rating of your tire no matter which way you do it .
Load Range and tire size are far more important than brand .
So if you gan go from a "C " rated into a "D" or an "E" that is a good way to go.
If you can go to a 215 or 225 section width over your stock 205 that is another way to go .
the important number assuming you are only considering ST tires is the weight capacity in pounds your replacement tire is .
there are plenty of choices in 225/75 R 15 in load range C and in load range D .
in practical experience the advantage of a 225 over a 205 outweighs any issues with rim width .
the best solution I have seen in 15 inch tires is the Continental Vanco 2 tire.

http://www.tirerack.com/tires/tires.jsp?tireMake=Continental&tireModel=Vanco+2&sidewall=Blackwall&partnum=27R5V2&tab=Specs
size 225/70R15 C has a load rating of 2470 pounds on an LT tire scale. This is also a tire that is rated for 99 mph unlike an ST tire at 65 mph rating .
it is also available in a 215 section width , also with high load ratings.

[Chuck_Gail]

Several points. First, as said, what are your RIMS rated for? Rating usually stamped on rear, or in valley UNDER the tire. Putting LR-D on a LR-C rim is a THIRTY PERCENT OVERLOAD. Not what I call safe. Obviously LR-E is an even worse overload.

Second what is your current rim WIDTH? Most ST205/75R15's I've seen are mounted on 5 or 5.5" rim widths. Most ST225/75R15's seem to require a 6" minimum rim width. Again, be careful what you do.

[shakyjay]

To clarify some of the questions the trailer has gvwr of 7980 max I run it about 7600. Tongue weight is about 1100. Don't really want to change rims as I can't see justifying the expense for what little we are running at this time. The tires on it currently are the originals from when it was purchased in 2006 and have never given any problems, even though they are Chinese made. One of them has developed a slow leak and sidewalls are beginning to crack on all of them. I do store it at my house and typically check pressure every couple of weeks. I always run my tires at max pressure on the trailer.

My original thought was to go to a D rated tire seeing as to how there is really not much of a price differential. Salesman at tire store suggested the 225 E rated which sounded a bit like overkill to me. I think he is going off his own experience with a fifth wheel toy hauler that runs a lot heavier. In this area that is mostly what he sees and most of them run overloaded.

So I guess that really just leaves me to determine if I just go with an exact replacement which is a C rated tire or jump it up to the D rated.

Thanks for all your input it is really very helpful.

[Gdetrailer]

I personally feel that folks put way to much thought into the name on the tire. 99.9% of the tires are made by the same manufacturers onshore and off shore.

Basically they just change the MOLDS which have the manufacturer name to be sold in it.

I just replaced my Carlisles which had a manufacturer date of 7yrs (I had them for 6 yrs). The reason as to why I replaced them? Bad VALVE stems!

Thats right, I had one valve stem over winter BROKE OFF.

I decided since one stem broke the others would follow. Since I was needing to replace the stems it made sense to put new rubber on at the same time.

A search of the Internet revealed that there was a bad batch of valve stems sold which lined up with the time frame I had the new tires mounted.

There is a good chance that there is STILL bad valve stems being installed yet TODAY since there was millions of stems manufactured before the recall and many shops may have never seen the recall.

Chances are many people have had a bad valve stem and blamed the TIRE MANUFACTURER for the tire blowing out.

Simply put if the valve stem breaks it is the same result as a supposed "defective" tire, basically shredding the tire and trailer. The problem is the process of the tire shredding damages any evidence of the broken valve stem. Then EVERYONE on the forum jumps to conclusions and automatically blames the maker of the tire.

[skipnchar]

Think Maxxis. Never knew ANY Chinese made tire that could match them.