TT Tire advice - going from 14" to 15" - or??

[CHD_Dad]

Background - 32' TT (In sig line) / 6700# fully loaded as per CAT / Tandem axle towards middle of TT / 14" alloy rims.

So several years ago I had a blow out with a no-name OEM TT tire. Changing that on the side of the road with 80mph traffic going by while it was 95+ degrees sucked to say the least.

Bought new camper in 2012. Drove on OEM tires two trips and then swapped them out for current tires - Maxxis M8008 Load Range C in the OEM 205/75-14 size. They are about 2-1/2 years old now.

Trip home two weeks ago and - blowout! Now since the first blowout I have been anal about my tires. They are covered when not being used. I check tire pressure before all trips. I keep my speed at 65mph 90% of the time (may briefly increase to pass somebody). I check them for tread wear, sidewall wear, etc. No clue why it blew out but it did and not in a nice way. I have very minor damage to the wheel well of my TT but it is damage. I cant remember ever curbing it or hitting anything with it. Other tires all look great. The tire that blew look great with deep tread, no cracks, no bulges, nothing.

So now what do I do? Serious question! The only D range 14" tire I can find are Kumhos and I am fine with trying them out. I think Goodyear still makes a bia sply D as well for U Haul trailer use. I looked into them before but was worried about going bias ply.

Other option I have is going to a 15" rim but what exactly will that help? What am I missing to make my tires last longer? This is getting to be a pain and expensive if I need to replace tires every 2 years!! I've got wife, 3 kids and 2 dogs I am hauling around so safety is #1.

As for clearance I dont have much. It is a low trailer with closely spaced axles.
Stock - 205/75-14 C
In between tires - 5 inches
From top of tire to bottom of TT - 3.5"

I think I "may" get away with a 15" tire but it could be tight since they dont make a lower profile 15" that I am aware of that has the load carrying capacity needed to keep the OD the same.

Right now I have only 300# of extra carrying capacity total or a measly 75# per tire. I was thinking going to a D may help things run cooler and safer.

Advice? We have a big trip through the NC mountains in a couple months and the last thing I want to worry about is tires!

[JIMNLIN]

So the big questions that remain for me are: does a commercial style tire have the proper design to withstand the loading unique to a trailer application? If so, is a commercial tire (seemingly from a more reputable vendor than the ST-style options listed above) superior to the ST alternatives? And finally, who the heck sells a 14" alloy trailer wheel which is rated to withstand cold pressures of 65PSI??

Thank you to everyone who has already offered help.
Jon

At the top of the tire chain is a commercial grade or commercial use tire that stands up to all types of trailer use (not just RVs).
There is nothing unique about a ST tire internal construction as far as with standing side loads.
A ST tire and a LT tire and a all position tire all have the same FMVSS 571 tire bead unseating test. Nothing special about the ST being some how superior to a LT or a all position tire.......other than ST tire advertising.
Good read on the subject http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/23225970.cfm.


For a 14" wheel rated at 65 psi check out this add;

http wrote:

At one time HiSpec advertised a max pressure rating which was tied to the valve stem. Give HiSpec a 1-800.

[jonmacs22]

My summary of what I have found on the issue of 205 75 14 LOAD RANGE D options:

Well after the advice of some of the nice folks on here and a whole bunch of phone calls and google searches, this is where I have come out on the topic:

ST Tire Load Range 😧
Kenda Karrier KR03 http://specialty.kendatire.com/en-us/find-a-tire/trailer/karrier/ Capacity Rating of 2040lbs, Outside Diameter 26.3"
This tire is made by Kenda (Chinese) for a few other branded companies such as Loadstar.

Radial King: No website. I only found this through speaking directly with the folks at oneclicktires.com The tire is Load D and offered for $54/tire + shipping. I cannot find this manufacturer online.

Commercial Style Tires:
Hankook RA08: http://simpletire.com/hankook-195-r14-2000180-tires Capacity of 2094lbs, O. Diameter of ~26"
I cannot for the life of my find any information on this tire on Hankook's corporate website. So no clue whether or not it can be used for trailering or has been designated by the manufacturer as such. The sizing is a little different, so it is necessary to run a 195 style tire to fit a 205/75 application.

Maxxis Bravo UE-168: http://www.maxxis.com/catalog/tire-227-bravo-series-ue-168-n#sizes In this case, the closest sized tire that is made is a 185 style which is 1874lbs capacity and diameter of 25.7"

So the big questions that remain for me are: does a commercial style tire have the proper design to withstand the loading unique to a trailer application? If so, is a commercial tire (seemingly from a more reputable vendor than the ST-style options listed above) superior to the ST alternatives? And finally, who the heck sells a 14" alloy trailer wheel which is rated to withstand cold pressures of 65PSI??

Thank you to everyone who has already offered help.
Jon

[jonmacs22]

Dannyabear1 wrote:

gmw photos wrote:

CHD Dad wrote:
Don, I have the option of going with the Kumho D tires which will also up my capacity but back when I bought my Maxxis I didn't have that option. They're still the only D 14" I can find.

Raising trailer does nothing to help the tire to tire spacing that is controlled by axle location. It would help with wheel well spacing. I wasn't sure what the min clearance was. I also didn't know if going to a 15 gained any other advantages vs just getting the Kumho D tires.

Another 14" load range D, LT tire is the Hankook RA08, although I feel the availability of the Kumho 857 is better.
If you could use the 15" good year Cargo G26, then it's load capacity is greater than the Kumho simply because it's a bigger tire. Look on tire rack for it's specs.

The Hankook RA08 is a great tire, LRD, 8 ply, 99 mph rated.. Got mine fresh from www.busdepot.com. $500 and some change for 4 shipped to me.

I cannot locate the Hankook RA08 on the manufacturer site. I can find it for sale on a few online retailer sites, but that's it. Any idea how one can research this to see if it truly is a proper trailer-use tire and has the necessary sidewall reinforcement to deal with trailering specific loads???

[CHD_Dad]

OK, wanted to update on this.

I finally mounted these up over the weekend. 15 x 7 aluminum trailer wheels mounted with Goodyear Wrangler HT's in a 215/75-15 D range. Spacing was tight but not in the spots I thought it would be. It is close around the plastic trim over the wheel wells and I can just get my fingers behind the rear of the tire. Took it for a 20 mile test run and it went well. My only concern is the tires have pretty deep tread so I hope they dont chunk at all during tight turns or maneuvering. Happy to have 1200# more carrying capacity along with a much higher speed safety margin. I dont tow fast as it is but I think the restrictions on ST tires is a little ridiculous.

Moderator edit to re-size picture to forum recommended limit of 640px maximum width.

[CHD_Dad]

tinner12002 wrote:

CHD Dad wrote:
Gmw, thanks for that tire option! They look great and I'm calling my tire guy in the morning. The 195/70-15 is actually a half inch smaller in Dia vs my current 14" tire so clearance is a non issue.

The 225/70 size is 1.3" larger in Dia so I'd lose almost 3" of space between tires. I think 2" is cutting it close!

You have to realize that if a tire is 1.5 inches taller than yours then you are only loosing 1.5 inches between 2 tires because you would divide the overall increase by 2 to see how much you would lose on each side. Or on top for clearance you would only lose 3/4". So basically you would lose 3/4" all around each tire which equals to 1.5" of diameter increase.

Oof, bad math on my part! You of course are right. I think I may look into the larger 225 size. My TT already sits low and I wasnt looking forward to it being even lower. I've scraped the rear leveling jacks a few times on steep ramps or sites.

[tinner12002]

CHD Dad wrote:
Gmw, thanks for that tire option! They look great and I'm calling my tire guy in the morning. The 195/70-15 is actually a half inch smaller in Dia vs my current 14" tire so clearance is a non issue.

The 225/70 size is 1.3" larger in Dia so I'd lose almost 3" of space between tires. I think 2" is cutting it close!

You have to realize that if a tire is 1.5 inches taller than yours then you are only loosing 1.5 inches between 2 tires because you would divide the overall increase by 2 to see how much you would lose on each side. Or on top for clearance you would only lose 3/4". So basically you would lose 3/4" all around each tire which equals to 1.5" of diameter increase.

[gmw_photos]

Jim, regarding the Vanco 2, I think it may be a tire that is being phased out of the lineup, so availability may be limited ? I'm not sure on that, but tire rack has been showing it as 'closeout' for a while.
And Danny, that's good to hear the Hankook is still carried by bus depot. I had forgotten about them carrying that tire.

To the OP and anyone else considering upsizing tires, don't forget to consider the appropriate rim width for any tire you are considering.

[2012Coleman]

Goodyear makes a load range D 8 ply radial tire called the Gladiator. I believe it comes in 14 in.

I don't have room for the Cargo tire, but here is info on it copied from a post in the TT forum - sorry, don't have time to directly quote it and give credit to the OP:

Goodyear Cargo G26
size : 225/70 R 15
Rated at 2470 # load on the LT rating scale
Not the 15 % wimpier ST rating scale .
Speed rating is 106 mph .
This tire weighs 33 # .
Load range D means you only inflate to 65 psi to get your max weight rating .
It fits on most 15 inch rv steel wheels without issues .
The typical Maxxis (and other ) ST 225/75R15 weighs about 29 # .
The Cargo G26 is made for European passenger vans such as the Mercedes Sprinter Vans .
readily available on tire rack and every goodyear dealer .
go here for complete specs :

http://www.tirerack.com/tires/tires.jsp?tireMake=Goodyear&tireModel=Cargo+G26&sidewall=Blackwall&partnum=27R5G26&tab=Sizes

[JIMNLIN]

CHDAD wrote:
The 225/70 size is 1.3" larger in Dia so I'd lose almost 3" of space between tires. I think 2" is cutting it close!

If you decide to go to 15 wheels it allows a great upgrade to a Goodyear Wrangler H/T in a LT215/75-15 D load range at 2095 lbs capacity.
And just about all major brand LT tire makers have a LT235/75-15 C load range at 1985 lbs capacity. Its a tall tire so watch the diameter.

Another excellent tire for trailer service is the 15" Euro size "all position" tire is the Continental Vanco 2 tire.
And as others have mentioned the 14" "all position" Hankook RA08, the G26 and Kumho 857 tires.

Check them out.

[ScottG]

Something I just played around with lately...
I wanted to raise my TT just a bit and since I have the shortest shackles already, I couldn't lift it that way.
I ended up installing a taller (but not wider) equalizer. It was 1.5" taller than the orig part so it lifted the TT .75". It also separated the tires by roughly 1~2" more (now 7" apart).
So if going to bigger tires and you need more room, this is one avenue if you can find the appropriate equalizer.

[Dannyabear1]

gmw photos wrote:

CHD Dad wrote:
Don, I have the option of going with the Kumho D tires which will also up my capacity but back when I bought my Maxxis I didn't have that option. They're still the only D 14" I can find.

Raising trailer does nothing to help the tire to tire spacing that is controlled by axle location. It would help with wheel well spacing. I wasn't sure what the min clearance was. I also didn't know if going to a 15 gained any other advantages vs just getting the Kumho D tires.

Another 14" load range D, LT tire is the Hankook RA08, although I feel the availability of the Kumho 857 is better.
If you could use the 15" good year Cargo G26, then it's load capacity is greater than the Kumho simply because it's a bigger tire. Look on tire rack for it's specs.

The Hankook RA08 is a great tire, LRD, 8 ply, 99 mph rated.. Got mine fresh from www.busdepot.com. $500 and some change for 4 shipped to me.

[Bill___Kate]

I agree with the recommendation to go to 15" if you can, but if you have to stick with 225/75 14's, Kenda Karrier has a Load Range D Radial, and I am pretty sure Hercules has both a Load Range D Radial, as well as a Load Range D bias. Haven't heard much about the Hercules, but I had a set of Kenda Karriers on my last trailer, and they appeared to be considerably heavier than the Maxxis Load Range C's I took off, and lasted three years until we traded the trailer.

[donn0128]

You have 5 inches between tires? Heck, my 13,500 pound fiver has run for 10 years with less than 2 inches between tires. Never had a problem with that little, so going up in diameter is a no brainer, IF you find raising the trailer a couple inches would work for you.

[CHD_Dad]

Gmw, thanks for that tire option! They look great and I'm calling my tire guy in the morning. The 195/70-15 is actually a half inch smaller in Dia vs my current 14" tire so clearance is a non issue.

The 225/70 size is 1.3" larger in Dia so I'd lose almost 3" of space between tires. I think 2" is cutting it close!