Visit our Popular Forums

Chitown AirStreamers · 07-31-2008, 11:56 AM

Thanks andy!!!

Gil Reinke · 07-31-2008, 12:22 PM

Can anyone tell me what speed the Goodyear TT are rated at. ? I have ST 225 75rx 15 range D I usually trave between 58 & 62 but If I have to pass and reach 70 to 75 I beging to worry if they are safe

Inland RV Center, In · 07-31-2008, 01:28 PM

Quote:

Originally Posted by Gil Reinke

Can anyone tell me what speed the Goodyear TT are rated at. ? I have ST 225 75rx 15 range D I usually trave between 58 & 62 but If I have to pass and reach 70 to 75 I beging to worry if they are safe

The following information is provided by Goodyear, specificly for the Marathon ST tires.

Industry standards are restricted to 65 mph, under normal inflation, for the ST (special trailer) tires.

They also say, that industry standards for the ST designation, can be used at speeds from 66 to 75 mph, however, the cold tire inflation MUST be increased 10 psi, above the recommended pressure.

The cold inflation pressure, must not exceed 10 psi, beyond the inflation specified for the maximum load of the tire.

Important tire care information and the load/inflation tables are available on Goodyear's Recreational Vehicle web site at On The Wings of Goodyear | RV Tires - Home

Additionally, the steel wheels as used by Airstream, MUST NOT exceed 75 psi, with a "COLD" tire.

Vehicle speed, load and inflation pressures, and proper balancing, all of which are within the control of the driver, are CRITICAL FACTORS for the safe and enjoyable operation.

Andy

Minnie's Mate · 07-31-2008, 02:26 PM

Andy, perhaps you can help me figure these load tables out. I have a 30' Safari with a GVWR of 7,500 LBS, if I remember correctly (I don't have the paper work here at the office). Dry weight, IIRC, is 6,800 LBS.

When I purchased the trailer new in 2006, the dealer did an excellent job of pre-walk through prep from what I could tell. I asked key questions that I had learned on this forum such as did he pack the bearings and he said yes. I later confirmed he had when I had the bearings re-packed the following Spring as part of my pre-season prep. Anyway, the tires contained 48-50 PSI in each tire per my digital gage the first time I checked them. I thought this was low per the Goodyear table I had discovered through a link in another thread on this forum at the time so I increased the pressure to the max of 65 PSI feeling this would give me a safety margin for travel on interstates and passing semi's on hills. Admittedly, I didn't understand how to read the table then and still am not sure I do now.

When I divide my GVWR of 7,500 by 4 tires I get 1,875 LBS of load per tire. In the chart the column with the next number above 1,875 says I need 45 PSI in each tire for a max speed of 65. Am I calculating the load correctly?

Cos · 08-01-2008, 09:57 AM

Andy - I think the people using E rated tires are not inflating them to the E rating at 80 psi but rather running 50 - 60 psi to restore the "soft ride" while getting a tire with a better speed rating than the Marathon.

If you take Goodyear's advice and add 10 psi to feel comfortable about the 65mph range aren't you also killing the "soft ride" of a D Marathon?

Lumatic · 08-01-2008, 12:56 PM

I left getting some new tires up to my mechanic. He put on "Hi Run", a brand I never heard of saying it was a good inexpensive tire. At the time I propbably would have chosen something more name brand, but the tires were on. 10,000 miles later and no complaints. But if anyone has any info on these tires I would be interested.

robert claus · 08-01-2008, 03:02 PM

You can order your tires from Tire Rack tirerack.com, and have them shipped to an installer (or shipped to you) - I highly recommend KO tire in Elk Grove Village. I ordered D rated Goodyear Marathons for my Bambi, and they are great. They replaced the original, 8 year old C rated Goodyear Marathons that were the original tires still on the trailer. They had plenty of tread, no weather checking, and had never presented any problems to the original owners, but the age made me nervous. The new tires, set to 60-65psi, track and ride great.

robert claus · 08-01-2008, 05:53 PM

oh, yeah, the original tires were not balanced. No weights whatsoever. Probably shook like crazy. The new Marathons have been balanced, and like all Goodyears (even the German Goodyears on my Sprinter) they took a lot of weight. Michelins hardly ever require much weight, in my experience, and if they'd offered a trailer tire I could use I would have bought them. OTOH, the Goodyesrs seem a good value. I pulled the wheels and took them over to the installer and picked them up later, as opposed to hauling the trailer over there.

Ray Eklund · 08-01-2008, 07:16 PM

Quote:

Originally Posted by Lumatic

I left getting some new tires up to my mechanic. He put on "Hi Run", a brand I never heard of saying it was a good inexpensive tire. At the time I propbably would have chosen something more name brand, but the tires were on. 10,000 miles later and no complaints. But if anyone has any info on these tires I would be interested.

Hi Lumatic,
I had purchased four Hi Run tires from Plains Tire Co., Rock Springs, Wyoming at $57.21 each on 8-1-2007, balanced and mounting included. Made in China, 215/75D14 Trailer Use-Load Range C for my 23 foot, 2006 Safari. After several weeks I was sitting in the lawn chair on a camping trip I noticed the treads were no longer flat, but were irregular when viewing from across. Between each of the treads, splits were developing between the treads on two tires. They were about 1 to 2 inch splits... everywhere. Whoa... Green River, Wyoming had a Plains Tire Co., no Hi Run tires and the cause of the splitting... over weighted trailer. Yeah Right.

Immediately driving to Salt Lake City, Utah to find replacement tires, I found Les Schwab Tires and bought a set of TowMaxx 14 inch tires, mounted and balanced for $353.27 on 8-16-07 and have been happy since... (I cannot find their receipt with the rest of the tire size information, as I write.)

You might just keep a close look at the tread looking irregular and check between the treads for splits. If you see the splitting, be prepared to take the blame for exceeding the manufacturer's specifications, if there ever was any intend to stand behind the tire.

Silvertwinkie · 08-01-2008, 09:11 PM

I went Maxxis load rating "D" and have been satisfied as I can be with about 1500 miles on them. I too was reluctant to go the Marathon route.

Lothlorian · 08-02-2008, 05:36 AM

I put 225 75 R15 Maxxis tires on my 73 Overlander. They are a "D" Load trailer tire. I called the Maxxis corporation and found a dealer close to my home. I have read much discussion on where many of these different brands of tires are made. I have read that it is important to know what country they were made in. Other RV folks I have spoke with all have their favorites.

I researched the cost of tires and installation for about two months. Do your home work. The prices are all over the place and so our the installation costs. I took mine to an old established tire shop that was around before all the franchise shops. It carried the Maxxis which I read was a good tire. I got the best tire price, and installation cost. Plus the character of the people, building and the shop I found appealling. It was an old place. It has seen some years and the people were friendly and residents for generations.

SIU Bound

Brian