Underrated Tires Being Used on Montana?

[rickfox]

Good Evening,

In the "Montana Problems and Technical Help" portion of this site is a discussion topic listed as "Mission Tires on 2006..." An upset purchaser stated that he recently purchased a 2006 3400RL that had 235/80R16 tires on it. According to the Mountaineer website, in 2006 Keystone started using this sized tire on the heavier 5th wheelers - all of which are significantly lighter than many of the Montana models.

The Montana website also states that all Montana models will be outfitted with 235/85R16E load rated tires.

Has anyone else purchased their new Montana with the 235/80 sized tires? It seems like a significant safety issue to me since I was unable to find any reference to a 235/80R16E rated tire. In reading posts on this and other RV related web sites, it seems to me that one of the most talked of safety issues is tire failure - usually as a result of overloading.

Hopefully this was simply a mistake, and not how the 2006 Montanas are really being built.

[rickfox]

Good Evening All,

I guess since no one responded, it means having the wrong tires delivered on new Monty's is NOT a problem.

Makes me feel better since I was told today by the dealer that our new 3400RL is supposed to arrive this coming Friday. They will do their thing and I should be ready to do my thing and take it home this coming Saturday - assuming no problems are found during the PDI's.

My first stop on the way home will be to get the baby weighed. I will report back on my findings and hope to be as excited as I can be about my new super toy!

[Countryfolks]

Ours are Tacoma [Coopers?]235/85 R16, rated to 3040 lbs at 80 psi. No trouble so far. You might check the rating on them when you pick it up. There seems to be a lot of dis-satisfaction with the Mission tires on a web search. Apparently the tires are made in Taipai by Nangkung Rubber Tire Co.

Skip

[sreigle]

Well, we have one of the heaviest Montanas around, at scaled weight of 14,360. The weight on the axles is 11,060. The axles are rated for 6,000 lbs each. The tires on ours are the size stated above, 235/80R16. However, ours are load range D, not E. That's what this Montana came with. Each tire is rated for something over 3,000 lbs. That's more than enough to handle the axle rating and also a thousand pounds (total) more than the actual axle weight. I guess I don't see a problem so long as the tires are rated sufficiently and properly inflated. Am I missing the point?

I cannot speak to the Mission brand but have heard of no more problems than we've had with our Goodyear Marathons and others with Michelin, etc.

[rickfox]

Good Afternoon Steve and Others,

I have been doing some more research and found that Goodyear manufactures a 235/80r16 tire size under the name Marathon. According to Goodyear, this size is made specifically for trailers - including 5ers. I have also found that a lot of the 5er manufacturers are now using this size.

These tires are slightly shorter and wider than the 235/85r16 tires, and the Marathon has a more flexible fabric side wall while a lot of the 235/85r16 tires have steel belted side walls. Goodyear apparently only makes up to a "D" rated tire, but this tire has a load rating of 3000# at 65PSI. This makes for a much softer ride when compared to the 3042# at 80PSI for the 235/85r16E.

All in all, it seems to me that the 235/80r16 tires are "better suited" to the 5er requirements - assuming the tires are in fact well built!

Sometimes, change is for the better.

By the way Steve, did the 235/80r16D tires come on your '03 3295? Were they the Marathons, and how many miles do you have on them?

[ken]

Our 2003 Montana came with the ST 235/80R16 tires that Steve had. I also questioned Keystone about them when we were there in 2004. They stated that they were as good or better because they were designed for Travel Trailers. I questioned the lower air pressure and the bounce we had with them. Our new 2005 has the 235/85R16s Load Es that are rated at 80 lbs. I ran the 2003 for over 20,000 and only lost one tire. Goodyear replaced it. Air was coming thru the side and created a bulge the size of a football before it blew. I was glad the tire had been changed and was laying in the back of the truck at the Goodyear dealer when it blew..

[Wrenchtraveller]

I picked up my 06 Montana 2955RL yesterday and I was not happy when I saw it had the Mission 235/80 16s on. The 235/85s are 31.7 inches high and the lower 80 series are 30.8 , almost an inch lower.

I put a complaint in with my service manager that all the brochures state the Montanas come with the 85 series tire and I got the 80 series tire. We will take this up with Keystone.

Having said that, my 235/80 series are Load range E, 10 ply rating and take 80 PSI.
They are good for 3520 pounds a tire or 14080 pounds for the set so I would overload the coach's springs way before I would unload the tires. It seems the only negative for me is the 1 inch lower stance of the trailer, not a real big deal.

[Trailer Trash 2]

quote:Originally posted by Wrenchtraveller

I picked up my 06 Montana 2955RL yesterday and I was not happy when I saw it had the Mission 235/80 16s on. The 235/85s are 31.7 inches high and the lower 80 series are 30.8 , almost an inch lower.

It seems the only negative for me is the 1 inch lower stance of the trailer, not a real big deal.

Well I wouldnt care if they were 1 inch eather way, I bet it had the newer axel with the eight lugnuts, most of us overload our trailers anyway dont we? and some of us have a truck with this realy powerfull motor and don't have a brake system strong enugh to stop this monster safely in an emergency situation. I have had no truble with my tiers,axels,or springs and I have the other axel 6 lugnuts and 16 inch rims.

TT2

[DHenry]

I have the same axel as TT2, 6 lug and 16" rims. My only concern was the valve stems on the tires. I had two of them fail within 1/2 hour of each other. I was told by the guys at the tire shop that the valve stems that were in the tires were only rated for 50 psi and I had the tires inflated to 80 psi as it said on the side of the tire. I had the valve stem changed and have had no problems since.

[Wrenchtraveller]

quote:Originally posted by Trailer Trash 2

Well I wouldnt care if they were 1 inch eather way, I bet it had the newer axel with the eight lugnuts, most of us overload our trailers anyway dont we? and some of us have a truck with this realy powerfull motor and don't have a brake system strong enugh to stop this monster safely in an emergency situation. I have had no truble with my tiers,axels,or springs and I have the other axel 6 lugnuts and 16 inch rims.

So, what's your point?

TT2

[sreigle]

1 inch greater diameter results in just a half inch higher rig. The other 1/2 inch is above the axle.

By the way, here's the text from a Keystone letter about the load range D tires Ken and we had on our Montana (we still have them).



Ken, did your football tire look something like this? This is on day 3 and it got considerably bigger before the replacement arrived. Never did blow, though.

[Bill Frisbee]

Hi, Steve ...

I am now more confused than ever. The letter you posted outlining the virtues of the ST235/80R16 tire is dated September, 2002. More than 3 years have passed and the new Montys I have seen all come with LT235/85R16 tires. If the STs are so much better, why isn't Keystone installing them on their '05 and '06 models? Sounds to me as though a decision was made by someone in 2002 and others were left to develop a rationale for that decision. I have a bias toward decisions made in the reverse order and on the basis of solid scientific/engineering evidence.

Bill

[Trailer Trash 2]

quote:Originally posted by Wrenchtraveller

The point is The tires on the trailer now are better than 2004's and the 05's too. "thats the point."

TT2

[Wrenchtraveller]

Thanks, this is great information for me . My tires are Trailer tires also and they are load range E and good for 3520 pounds so I think I will keep them. The height I am glad to hear is no big deal but the reason I was concerned is I live on Vancouver Island and I had to take my trailer on the BC ferries to get it home. These are good size boats that carry over 400 vehicles but if the tide is low, the ramps can be quite severe and the design of the 2955RL has the door steps pretty close to the ground. The models with the doors ahead of the wheels are fine but I was worried that my steps might bottom out on the ferry ramp so I removed them. There are only four 3/8 carriage bolts holding them on so it only takes a 9/16 socket and about 5 minutes to take them off. Better to be safe than sorry. I will do this everytime I take my rig off the Island,
Thanks again, Wrench.

[sreigle]

Bill, I think they were trying to explain that a load range D trailer tire (ST rather than LT) in that size meets the requirements where a load range E is necessary in an LT light truck tire. After that memo I quit worrying about it. We have had some tire problems but I don't think it was related to whether the tires are ST or LT or Load Range D or E. Sorry if I confused you!

[rickfox]

Good Evening All,

We picked up our new 3400RL this past Saturday. The tires on this unit are Mission 235/80R16E rather than the D rated tires. According to the dealer, these tires must be run at 80 PSI to support the 3000# load. I did not see a PSI at rated load marking on the tire.

Like many of us, I have done some research and am aware of the "published specs" of the 235/80R16D tires that seem to indicate their better use for trailers. Unfortunately, thus far I have not been able to locate any information on these E rated tires. And there was absolutely ZERO written information provided by the dealer or contained in the Keystone documentation. I believe there is supposed to be information on the GVWR label on the outside label. I will check that and report back.

At this time, I don't know whether to be satisfied or not about the tires!!

As far as the trailer is otherwise concerned, portions of the color scheme were different than advertised, but both my wife and I actually liked what they did better and were happily surprised - in this case.

Overall, the fit, finish, construction, etc. was better than I expected, with only a couple of problems to deal with. In this respect, thus far we are very happy! We'll know more after our shakedown cruise.

[Bill Frisbee]

quote:Originally posted by sreigle

Bill, I think they were trying to explain that a load range D trailer tire (ST rather than LT) in that size meets the requirements where a load range E is necessary in an LT light truck tire. After that memo I quit worrying about it. We have had some tire problems but I don't think it was related to whether the tires are ST or LT or Load Range D or E. Sorry if I confused you!

Hi, Steve,

Thanks for the information. I am going to spend the winter investigating alternatives to the Tacomas that came on our unit. At the very least, I would like to be able to check out the specs on the tires I install, somthing I am unable to do with Tacomas. My current thinking is to replace the Tacomas with Goodyear G614RSTs. The bad news is that the Goodyear web site says that their 235/85R16s have an overall diameter of 30.7 inches. Going through the conversion mathematics, this tire should either be 31.7 inches in diameter or have a different number attached. Clearly, there is an error somewhere ... which leads me to wonder what other specification errors are on the Goodyear site???

The good news is that these questions give me something RV-related to work on through the long Ontario winter ... while so many MOC members are basking in the warmth of RGV or south Florida. In a few more years I will have all the answers (LOL) and we can join the southern migration.

Bill

[sreigle]

Rick, load range E tires do require 80 psi to reach rated load capability, as you mentioned.

Bill, I've heard good things about the new Goodyear G-series tires but I thought they were only available in Class A sizes, like the 22.5 inchers. I'm glad to hear otherwise. I would think diameter would also include tread depth. I know that varies from tire model to model and brand to brand. But if your numbers are correct then tread depth would be less by 1/2 inch than other brands. That doesn't sound plausible. Let us know what you find out.

[Bill Frisbee]

Hi, Steve ..

This is the web site I am going by. They also list Marathon and Wrangler HT as appropriate tires for RVs. Will see if they are actually available and let you know.

Bill


http://www.goodyear.com/rv/products/...t_g614rst.html