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Old 07-19-2015, 09:18 AM   #11
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Originally Posted by BarbaraG View Post
So, I found the measured weights (in lbs) for the four corners of my RV:

RF 2950 RR 5150
LF 3000 LR 5300

My tires are Goodyear 245/70R19.5

According to the table, in Single configuration they should be at 80 psi for 3640 lbs, and in Dual configuration they should be at 80 psi for 3415 (there are no values listed below these). I assume the Dual values are per tire, for which I'm at a max of 2650 lbs. Based on this, I think I should go back to the 82 psi they were originally set at.

Of course, these weights were a year ago, but at least they give me a ballpark idea. Looks like I need to find a place to get the weights done again.

Thanks again for the guidance.

Barbara
2014 FR3 30DS

Barb, Good Work. I agree with your decision to have something slightly above 80 as your Cold Inflation Pressure. 82 or 85 whichever is easier to read on your tire gauge sounds fine.

Do you have a TPMS? If you do you could set the low pressure warning to 80 so you would get plenty of advance warning if you get a puncture.

RE weighing again. I would suggest a simple axle weight at a truck scale would be sufficient for a check. If the toal hasn't changed much and if you haven't moved your "bowling ball collection" from one side of the RV to the other you should be good to go.
I did 4 corner weights a number of years ago. Each year since then I run across a truck scale jsut to keep an eye on the numbers. I see +/- a couple hundred pounds and so I get confirmation that there was no significant change in tire loading.
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Old 07-19-2015, 11:48 AM   #12
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Barb, Yup, Sounds like you nailed it. Same thing we did.

Use one of those Brother label maker things and make labels for all the wheel wells.. i.e. MIN PRESSURE = 82psi
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Old 07-19-2015, 02:50 PM   #13
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Am I missing something here? The Ford chassis used on the 28DS and the 30DS is an 18000 Lbs chassis. That is 6000 lbs on the front and 12000 on the rear fully loaded. So I don't think any FR3 should have more than 82 psi in the tires ( which is the amount on the sticker inside my motorhome). If you have more weight than that, you have overloaded the frame.

Just my 2 cents.

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Old 07-19-2015, 03:29 PM   #14
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Tireman9,

Yes. I do have a TPMS. Wouldn't leave home without it.

Thanks.

Barbara
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Old 07-19-2015, 04:16 PM   #15
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Quote:
Originally Posted by BarbaraG View Post
So, I found the measured weights (in lbs) for the four corners of my RV:

RF 2950 RR 5150
LF 3000 LR 5300

My tires are Goodyear 245/70R19.5

According to the table, in Single configuration they should be at 80 psi for 3640 lbs, and in Dual configuration they should be at 80 psi for 3415 (there are no values listed below these). I assume the Dual values are per tire, for which I'm at a max of 2650 lbs. Based on this, I think I should go back to the 82 psi they were originally set at.

Of course, these weights were a year ago, but at least they give me a ballpark idea. Looks like I need to find a place to get the weights done again.

Thanks again for the guidance.

Barbara
2014 FR3 30DS
At the bottom of page 6/45 of next pdf of Goodyear I found 2 times your sises with stange differences.
http://www.goodyeartrucktires.com/pd...dinflation.pdf

The maximum loads and minimum pressure of 80 psi tels me its the G load/F-load list in wich Dual is only 1 li step lower ten Single.
In the H-load list beneath that its 2LI steps lower, wich is the system used .
already warned Goodyear a while ago for that to my opinion mistake.

So its better to get the tire data from the sidewall, still dont know now if you have F- G- or H-load tires . Search for LRG ( H or F).
Or search for something like "maximum load single 4540 lbs AT 110 psi ( cold) " and see if for Dual load its the same as in the list of Goodyear.
Also try to detemine the Speedcode , most likely for these tires N=max speed of 140km/87m/h.

For the moment I will not go from your given data so single maxload 4540 lbs AT 110 psi, And the dual load calculated lower 7.5% , but from H-load Single maxload 4940 lbs AT 120 psi, because it will give the highest psi as answer.

Asuming your rear to be dual load so 4 tires on 1 axle, if its tandem axle let me know.

First filled in part 1 for the tires and 4 tires on 1 axle , and part 3 for given 4 point weighing, then read the axle load there and filled it in part 2 and made picture of the complete page .

It shows that 80 psi is more then enaugh and then still reserve , but calculated for probably N speedrated. If I calculate the maxload for Q speedrated only to give lesser deflection with still no bumping, the answer would be F 83 psi and R 79 psi , so maximum needed pressure with still acceptable comfort and gripp , and maximum reserve.

Here the picture with the advice assuming N speedrated tires and no reduction for lesser deflection.
If you give the corrected data I will re-calculate, but it shows that 100 psi is absolutely not needed.


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Old 07-19-2015, 06:31 PM   #16
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The tire pressures indicated in the tables are MINIMUM for the weight. i.e. if you have X weight on that tire, you must have at least Y pressure.
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Old 07-19-2015, 10:34 PM   #17
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I run mine @ 90


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