The Goodyear web site is hard to navigate, but I finally found the right link at
http://www.goodyear.com/rv/products/..._marathon.html. Not all of the entries in the table make sense to me, but most of our questions can probably be answered here. The 14-inch 205 tire that has been described in earlier posts is possibly a Load Range B tire (carrying capacity 1430 pounds) or more likely a Load Range C tire (carrying capacity 1760 pounds). The load range is printed on the sidewall, and I would guess that all of the posts refer to the Load Range C tire.
I am trying to put all this together, because I am not entirely comfortable with the load rating on my tires vs the loaded weight of the TM. I went through the following steps to determine whether I could upgrade. The specifics may be different for your TM, but the general idea should be the same.
My TM came equipped with ST215/75R14 tires. This is a 14" Load Range C tire, rated for 1870 pounds. Therefore two tires can carry 3740 pounds. According to the label inside the TM, after I add propane and fresh water (but no black or gray water), I am left with something like 800 pounds of capacity for all our stuff. Now, I don't think we have 800 pounds of stuff, but I bet we do add 400 pounds, and the remaining 400 pounds doesn't seem like much reserve to me.
Unfortunately, the Goodyear web site says that the next step up requires a 15" tire. The ST225/75R15 tire is Load Range C (2150 pounds), which would make me very comfortable. The tire is slightly thicker (225 mm as opposed to 215 mm), but 10 mm is just under 1/2", and that is probably manageable. However, the tire diameter increases from 26.7 to 28.3 inches - an increase of 1.6 inches. As near as I can tell, this is probably NOT manageable, at least on my TM. By eyeball, I have only about an inch of clearance between the top of the tire and the inside of the wheelwell liner. With the bigger tire, almost no clearance would be left, and as the suspension goes up and down, the tire would hit the wheelwell.
A lift kit might have solved the problem, since it raises the trailer body (and hence the wheelwell liners) up away from the axle. This should increase the clearance between the top of the tire and the wheelwell. Wade, can you tell how much clearance you have above the tire?
For me, it appears that a solution might be to unscrew the wheelwell liners from the floor of the TM (inside the kitchen cabinets), insert a 1" thick wooden "rim" around the wheelwell cutout in the floor, and reset the wheelwell liner on the rim. Any comments or thoughts?
The larger tire would also come closer to the front and back of the wheelwell liner, but there seems to be more clearance here. Also, since the spring action is up-and-down, I wouldn't expect the fore-and-aft clearance to be subject to much change during driving. Maybe a reduced clearance is OK here - any thoughts? Wade, can you tell how much fore-and-aft clearance you have?
I am unable to identify an "outrigger" in this area of my TM. Surely the outrigger is not the steel frame member that extends behind each tire. What is it? Did it go away in the new units?
Thanks for all thoughts and inputs.
Bill