Should I change the tires on the 5th Wheel

FlowerChild · 02-07-2017, 08:31 AM

Greetings,

Just picked up my new 2017 Montana 3791RD. Someone mentioned that I should immediately upgrade the tires. What are your opinions?

Current tires are: ST235/80R16E

Flower

66joej · 02-07-2017, 08:59 AM

Don't see a need to replace tires as long as the manufacturing date is fairly current. If you don't feel comfortable with what came with the 5er by all means replace. Mind you if you are against made in China tires these will probably be the replacements as they are all made over there save for one (Goodyear Endurance).

Tbos · 02-07-2017, 09:23 AM

You'll find some that will say yes and others with success on their OEM tires. At a minimum I'd buy a tire pressure monitoring system. That way if there is a problem hopefully you'll know about it before it destroys anything. Always check your pressures and keep your speed below 65 with the OEM. If you hit a curb change that tire immediately. Enjoy your new rig.

2016 Passport GT 2810BHS, 2014 Silverado 1500 LT in Deep Forest Green

**JRTJH** · 02-07-2017, 09:39 AM

The tires on your new trailer are "BARE MINIMUM" for the GVW weight rating...

Here's how I come to that conclusion:

Empty weight: 13470
Payload: 3475

GVW: 16975
Pin (20%) 3389
Weight on tires 13586
Each tire (1/4) 3396

The "maximum weight rating" of the 235 80R 16 ST tire is 3420 pounds at 80PSI. So, the "new OEM tires" on your trailer are rated to carry the weight of each wheel (assuming they are all equally divided, which they probably are not) would give you a "spare capacity" of 24 pounds per tire. Considering that ST tires "degrade" approximately 10% per year, before you reach your first year of ownership, your trailer tires will be rated to carry about 3078 pounds. At GVW, that means you will have tires that are overloaded by about 318 pounds each. That's about a 1200 pound overload on your tires when the warranty expires.

If you look back through the threads in this section of the forum, you'll find that Keystone installs "barely adequate" tires on the majority of their trailers. What this means to you is that by the time you load your personal items, camping gear, food and the other things we all carry with us, you'll be at the upper limit of your tire capacity and, with a year or two of use, you'll probably be overloaded.

How you deal with this is up to you, but I'd suggest that, at the minimum, you load your trailer as you'll tow it, go to a CAT scale, weigh the rig and see exactly what your weight is. That way you'll know, to the pound, whether you need to address tires now, at the end of your first year, or whether you can "forget about tire capacity" for the first couple of years. My suspicion is that you'll find you need to get new, bigger tires (either Load Rating or size) if you want to have any "reserve tire capacity".....

Let us know as you load and weigh your trailer.

Good Luck,

**sourdough** · 02-07-2017, 10:32 AM

As has been said above the tires are bare minimum to legally carry your weight. Something I think about in those situations is the added stress put on the tires when hitting a pothole, undulating highways etc. Each of those situations, shoving the tire into the trailer exerts far more pressure on the tire. When they will barely support the trailer sitting still those situations cause me concern. You've got a lot of weight behind you tied to the truck; I would want the biggest margin I could get for my tires. X2 on a TPMS.

xrated · 02-07-2017, 11:05 AM

My new Impact 303 came with the Trailer Kings on it. I towed it home from the dealer and it has sat without moving for the last few months. I just got through ordering a set of 4 Maxxis 8008 replacements for it and they will go on either this weekend or next. I'm not taking any chances with the T.K. tires.

The Maxxis tires have a 123 rating, which equates to 3420 lbs per tire. My trailer has a GVWR of 13k lbs and about 1100-1200 lbs of tongue weight. That should give me a safety margin of around 450 lbs per tire. I seriously doubt that I will be at the full 13k GVWR, as the trailer is 9k and I have a load rating of 4k.

cardinal96ss · 02-07-2017, 03:01 PM

Two years ago, when deciding to replace tires, I upgraded my 36ft Montana wheels and tires to 17.5 inch / 120psi. While not cheap, if you are looking for replacement wheels you might want to check out the larger weight and speed margins this size provides. I dealt with the following company and received great service and fast delivery of mounted tires and wheels. http://www.trailertiresandwheels.com/
The tires are commercial Continental and phenomenal. They don't show any wear after about 8,000 miles and I feel very safe towing with them on the 5er.

ChuckS · 02-07-2017, 03:03 PM

My opinion... if they came with E rated tires I don't care what the brand is you don't have enough tires.. if the valve stems are not high pressure all metal you need to upgrade them to all metal high pressure valve stems...

It's your new Montana.. you paid a lot for it.. tons of threads and discussions previously posted , some with pics of damage done..

Now if your Montana came with factory G rated tires...and some now are, then at least upgrade those valve stems.. Run maximum pressure stamped on the sidewall, checked when cold.. keep your speed below 65...

If you do this, check your tires each fuel stop, maintain air pressure, then if they are G rated from factory I'd run them..

But, if they are E rated I wouldn't pull it anywhere except to a tire place to replace them....just saying....

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ChuckS · 02-07-2017, 03:16 PM

Looking at factory specs your rig is 41 feet and weigh a ton, empty.. you will be 15000 pounds most likely at least once you get everything inside that you want to carry... it to mention water weight, etc if you boon dock...
Empty sticker weight for your model is 13, 470

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CWtheMan · 02-07-2017, 03:18 PM

Quote:

Originally Posted by FlowerChild

Greetings,

Just picked up my new 2017 Montana 3791RD. Someone mentioned that I should immediately upgrade the tires. What are your opinions?

Current tires are: ST235/80R16E

Flower

Keystone cannot sell that trailer with ST235/80R16E tires without informing NHTSA that they informed you to only use tires with a load capacity of 3500# or above. It's a violation of FMVSS standards to not inform you of the proper tires to use on your trailer. ST Tires manufacturerd by Goodyear or Maxxis in size ST235/80R16E are rated at 3420# and do not qualify for fitment on 7000# GAWR axles. In fact, ST235/80R16E tires rated at 3520# do not qualify unless specifically mentioned in documentation to NHTSA. Thats because all tires of the same size with different load capacities defalt to the lowest load capacity without being documented.

Keystone is always having to perform recalls for for such errors. One would think they would have learned by now to clean-up that problem.

ChuckS · 02-07-2017, 03:22 PM

I can't believe they are still selling this big of a fifth wheel with E rated tires...

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Todd727 · 02-08-2017, 02:58 AM

When we bought our Cougar a couple of years ago, I immediately went to http://www.trailertiresandwheels.com/ and purchased four Goodyear 614's and new wheels from them. When they came in, I took the original tires and wheels off and used my new setup. When I sold the camper, I put the brand new OEM set back on.

You are now more fortunate than I was because you can choose the Sailun 637's and save a lot of money for what are turning out to be very good tires.

If you were closer, I'd sell you those wheels and tires, as I don't need them anymore. New camper uses 8 lugs vs. 6 and it came with Sailuns anyway.

FlowerChild · 02-09-2017, 12:35 PM

Thanks everyone for your excellent and informative replies. This is just what I was hoping to learn. Needless to say, I will be changing out the tires.

Thanks Again

dcg9381 · 02-10-2017, 09:25 AM

Same here, first thing I did was replace the factory tires.

RandyandDeb · 02-10-2017, 12:51 PM

Can anyone tell me what the diameter of the lug bolts (wheel studs) on a 355ts would be? Our unit hasn't been delivered yet and I contacted the Dealer to ask them this question and they didn't know. They did call Dexter and was told they are 1/2".
I know they are 8 bolt wheels, but don't know if I should take it for granted they got the correct answer from Dexter considering Dexter probably doesn't know for sure what units get what axles after they sell them to the manufacturer.
I have contacted Trailer Tires and Wheels and I plan to get 17.5" wheels with Goodyear G114 tires. We will easily be pushing up against the weight limits of the current setup loading a CanAm Spyder RT (wife's) and an Indian Scout (mine) along with everything else. Probably will never be able to carry full water tank and/or fuel station.

By the way, what aluminum wheels would you recommend?

Thanks in advance for your responses!

bsmith0404 · 02-11-2017, 05:19 AM

Quote:

Originally Posted by RandyandDeb

Can anyone tell me what the diameter of the lug bolts (wheel studs) on a 355ts would be? Our unit hasn't been delivered yet and I contacted the Dealer to ask them this question and they didn't know. They did call Dexter and was told they are 1/2".
I know they are 8 bolt wheels, but don't know if I should take it for granted they got the correct answer from Dexter considering Dexter probably doesn't know for sure what units get what axles after they sell them to the manufacturer.
I have contacted Trailer Tires and Wheels and I plan to get 17.5" wheels with Goodyear G114 tires. We will easily be pushing up against the weight limits of the current setup loading a CanAm Spyder RT (wife's) and an Indian Scout (mine) along with everything else. Probably will never be able to carry full water tank and/or fuel station.

By the way, what aluminum wheels would you recommend?

Thanks in advance for your responses!

All 8 lug RV axles are the same, the bolt pattern is 8x6.5 with a 4.90 center bore. I believe the lugs are 1/2", but you shouldn't have to get new lugs nuts, the OE ones should work with the new wheels. Here's a link to the Sendel Wheel site. They provide the majority of trailer wheels in the industry. They have a couple 17" options. Personally I stayed with the 16" wheels, but did just upgrade to T11BM, which is also available in 17.5". Got them off Amazon for $75 each with free shipping. Just a couple thoughts before you buy. 17.5" tires are harder to find and are very pricey. They also carry a very high load rating. The only ones I found were LRH which is nearly 5,000 lbs. Not sure how much flex that would give over bumps down the highway, even the cracks in the road could become a bit harsh and cause some stress. If your plan is to go 17" and an LT tire, that would probably give you more options.

http://sendelwheel.com/wheels/alumin...er-wheels.html

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