need new 5th wheel tires

[Big Bill]

I have a 2010 Montana 3665RE with ST235/80R16 Load Range E Goodyear Marathon tires (Chinese Bombs). I recently had a blowout and upon further inspection I noticed the other 3 tires have severe inside tire wear. They have approx. 10,000 miles on them. I would like to replace them with Michelin's but apparently they only come in an 85R16 not an 80R16. Does anyone know if this tire is an acceptable replacement, if not do you have any suggestions. Thanks
Big Bill

[RustyJC]

Check the manufacturer's websites for your current tires and the tires you're interested in using. Under the Specifications tab the manufacturers will provide the diameter for each size of tire. You should be able to switch to the 85 series tires as long as you have no less than 1.5" clearance between the new tires you're considering. Please note, though, that the LT235/85R-16 and the LT245/75R-16 XPS Ribs both have the same 3042 lb load rating, but the LT245/75R-16 has a 30.6" diameter compared to the LT235/85R-16 that has a 32.2" diameter. Despite the difference in section width in the official sizing, Michelin says that the 245s have an overall width of 9.6" versus 9.7" for the 235s. If you have the required 7" rims, it looks like the 245s could be used in place of the 235s with no problems! A very similar situation exists between the LT215/85 and the LT225/75 if you need the smaller tire. For your reference, the Michelin XPS Rib data is located HERE.

Rusty

[450Donn]

What is your fivers GVWR and what rating axles do you have? If you have 7K axles then you would be far better off getting 17.5 inch tire and wheel package and never look back.

[Big Bill]

The fivers GVWR is 15,545 GAWR front 6,750 GAWR rear 6,750. I recently had it it weighed by SmartWeigh at the Escapee's Escapade and the measured weights are Right front 2,890 Left front 3,050 Right rear 2,850 and Left rear 3,025. Thanks for your assisstance.
Big Bill

[RustyJC]

Looks like you need more than the 3042 lbs @ 80 PSIG rating of the XPS Rib.

That pretty well leaves you with a higher load rated ST 16" tire (), a G-rated Goodyear G614 RST 16" tire/wheel package (special wheels are required, and the G614s do NOT have a good track record, either ), or a 17.5" tire/wheel package, which I've switched over to as well. These 17.5" load range J tires are rated 4805 lbs @ 120 PSIG and have a smaller diameter than the G614 LT235/85R-16 tires they replaced. Not inexpensive, but well worth it for the peace of mind.

Rusty

[nosticks]

Big Bill, join the Montana Owners Club at Montana and Mountaineer Owners Campsite in Cyber Space This tire issue has been beaten to death resurrected and beaten again and again. You'll get info about your specific unit.

[Big Bill]

Thanks Rusty. Do you have a preference over either the 6.75 rim or the 7.5 rim?
Big Bill

[RustyJC]

I upgraded to 215/75R-17.5 load range J Michelin XTAs. Here's the wheel I used:




I bought the entire upgrade package (tires, wheels, lug nuts, center caps, mounted and balanced) from Trailer Tires and Wheels.com. If you wish, give Scott a call there and he can quote you what you need. If you don't like the Michelins, he has quite a selection of other 17.5 tires as well.

Rusty

[richardfry]

If You buy from scott at tire trailer & wheels. ask if he can adjust tires that he sells He told me I would have to go to a Good year dealer as he could not adjust tires . This means no service after sale. good price no service

[Big Bill]

Thanks for the input. Does anyone have experience with Power King TowMax STR ST235/80R16 Load Range E tires? They are weight rated to 3,520 pounds, which exceeds my maxium measured weight by approx. 500 pounds. According to their website they exceed federal tire standards by 40%. They are advertised as a "premium" tire. I was told the company is owned by Cooper Tires but could not confirm that on their website. Thx...
Big Bill

[RustyJC]

Quote:

Originally Posted by richardfry If You buy from scott at tire trailer & wheels. ask if he can adjust tires that he sells He told me I would have to go to a Good year dealer as he could not adjust tires . This means no service after sale. good price no service

Well, I guess that's a consideration, but on all my many Goodyear failures (Marathons on a previous 5th wheel and G614s on my current one), I've always been sent to one of Goodyear's factory-owned local stores anyway for the adjustment process.

Then again, I've never had a Michelin tire adjusted - I've never had an XPS Rib or XTA fail. If I did, though, I don't know how someone in Ohio could reasonably adjust a tire for me when I live NW of Houston, TX.

As in any dealing with a remote internet company, after weighing the positives and negatives, ya pays yore money and ya takes yore choice.

Rusty

[wingnut60]

If you purchase Michelin tires, I believe you can register them. Michelin will stand behind them based on tread wear/time. Goodyear does the same, but they have also paid for damages.
I made the same tire/wheel changeout that Rusty did, from same place. Did it in '07 and have not had a flat or basically any tread wear in over 20K miles since--and my MS weighs 17400.
If you can't live with an internet purchase, then buy locally and see if they stand behind the purchase if anything goes wrong--chances of having a claim locally is maybe the entire problem--most of the blowouts are some distance from where you bought anyway. Some dealers have a nationwide network for claims, but usually require some sort of upfront fee--I have heard that Discount Tire will insure any tire if you pay for the program.

[tnance]

Take the time to read these old posts about 16 inch tires and upgrades. Also click on the link for my post three years ago. This is where Rusty got his info.

We now have over 25,000 miles on the tires without any problems.

From a post 07-22-2011

17.5 inch wheel upgrade

I changed to G114’s over three years ago. Here is a post from two years ago.

Trailer Tires

So far I have not had any problems with the tires. At this point I would recommend the G114’s for those that have heavy trailers.

My 33 ft Teton weighs 17,500 lbs with approximately 3,500 lbs per tire. We have a minimum of 20,000 miles on the G114’s at this point.

[Ray,IN]

Big Bill, this tire size comparator will help you determine in advance if a certain tire size will fit properly. I too tired of the seemingly constant trailer tire problems. I solved my problem by changing to Sailun, load range G tires. That website offers 5 different brands of 16" load range G tires.