Help me with the math here. I seem to be having a problem with wanting some margin.
Our TT has ST205/75R14 tires on it (4 of them), which, according to the specs (published and on the sidewalls) have a maximum load of 1,760 lbs @ 50 PSI maximum.
4 X 1760 = 7,040 lbs maximum on the tires.
According to the manufacturers specs for the trailer, it has a dry weight of 6,555 lbs and a maximum capacity of 7,850 lbs and a toungue weight of 820 lbs.
If I take the maximum tire load and add the tongue weight, I get 7,860 lbs.
By my calculations, that leaves me with 10 lbs of margin.
Isn't that cutting it a bit close? Or am I calculating something wrong?
2008 Jayco Jay Feather 311
2008 Ford F-250 Lariat SD, 4 X 4,Crew Cab, 6.4L Diesel, Automatic, Trailer Tow Package
Equal-I-Zer WDH
'07 Nights camping = 36
'08 Nights camping = 34 (so far)
I wouldn't do the math that way. Best bet is to weigh the tt... what is axle weight when loaded down as you would normally camp/pull it? I'm guessing you will be over the 7,040 lbs rating for your class c tires. I would get a set of D's or even better a good set of E's.
Unless I'm wrong, you can't get a 14" st tire in anything other than load range C. You can gain some weight rating by going with a 215 size, or upgrade to a 15" wheel.
I'm facing the same problem, my trailer weighs right at 6500 lbs going down the road, and I have wore my tires completely down in under 8k miles. They look like they've been run extremely under-inflated, but I keep the tires at 50 psi religously.
This time around, I'm going to try a 215 radial. If that doesn't work, then I'll have to go to 15's.
I suggest going to a larger tire and/or weigh your TT so you don't overload the tires.
Even going to ST 215/75R14 tires would only give you a total tire weight load capacity of 7040# (6 ply rating)
* This post was
edited 08/04/08 06:45pm by amxpress *
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The reason I mentioned tongue weight before was just to be sure that I was calculating what the GVW is, and I as I understand it is the tongue weight plus the weight on the tires.
I am certain that I have more than 485# of stuff. As stated, none of the options or basics are included in the 6555 dry weight. As best as I can figure it right now, I am over the limit for the tires before I put anything in it considering propane, AC, etc.
I looked on the Goodyear website and they state that the 215's have a rating of 1,870 lbs, so I can gain a bit there, but not much.
Having just finished a 2,500 mile trip and having had a blowout on the trailer during it, I have spent a bit of time thinking about this.
Another item that I found was that when I went to get the tire that blew replaced, Wal-Mart tried to sell me a ST205/75D14. They were totally oblivious to the fact that they were suggesting that I mix bias ply and radials. They saw no problem with it.
alageezer wrote: Unless I'm wrong, you can't get a 14" st tire in anything other than load range C. You can gain some weight rating by going with a 215 size, or upgrade to a 15" wheel.
I'm facing the same problem, my trailer weighs right at 6500 lbs going down the road, and I have wore my tires completely down in under 8k miles. They look like they've been run extremely under-inflated, but I keep the tires at 50 psi religously.
This time around, I'm going to try a 215 radial. If that doesn't work, then I'll have to go to 15's.
Note on our dual axle TT, we found one wheel (the one under the fully loaded fridge) carried about 20% more weight than the other three. When you are so close to max IMO you need to for sure weigh wheels seperately.
Chuck
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2003 Wanderer 187TB Toybox (3620# UVW, 4800# loaded) Not yet camped in Hawaii, 2 Canada Provinces, & 2 Territories. I can't be lost because I don't care where this lovely road is going
One of the Maxxis tires I sell in this size is rated to hold a load of 1870 lbs at 50 psi.
Size
215/75R14
8.60
Ply Rating
6
Overall Diameter (inches)
26.7
Section Width (inches)
8.60
Max Load (lbs)
1,870
Max Psi
50
Tread Depth (inches)
9/32
Side Wall
BSW
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