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02-13-2021, 01:44 PM
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#1
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Senior Member
Name: Mary Jo
Trailer: 2020 Scamp w/2004 Volvo XC-70
Massachusetts
Posts: 341
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what should tire pressure be set at outside, up on chocks, wheels covered
My 13ft Scamp is outside, covered, on chock blocks with weight off of the axel, tires covered. I won't be using it until probably April, so it's been sitting since Nov. I've read that tire pressure should be 25% over the pressure on the tire. What should the tire pressure be while it's not being used?
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02-13-2021, 01:55 PM
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#2
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Senior Member
Name: Gordon
Trailer: 2015 Scamp (16 Std Layout 4) with '15 Toyota Sienna LE Tug
North Carolina
Posts: 5,156
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If the tires are on the ground and supporting weight then inflate the tires to the maximum pressure listed on the sidewall. If they are off the ground and not supporting any weight then inflate to about 15 PSI. Return to normal pressure when put back in service. Best is to remove them wheels and store in a climate controlled environment but if outdoors keep them covered.
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02-13-2021, 02:02 PM
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#3
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Senior Member
Name: Jon
Trailer: 2008 Scamp 13 S1
Arizona
Posts: 12,303
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Gordon’s advice is what I’ve been told is best practice. I’ve honestly never heard of inflating past the maximum sidewall pressure under any circumstances.
Mine’s in a garage on jack stands off the ground, but I’ve never bothered to lower the pressure. Too much trouble. We normally take a winter trip or two to the desert, so it rarely sits more than 3 months.
This past year has definitely not been normal!
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02-13-2021, 02:36 PM
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#4
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Senior Member
Trailer: 2002 19 ft Scamp 19 ft 5th Wheel
Posts: 3,641
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Me, I think worrying about the tire pressure is way to much to worry about. Just put your camper on blocks and forgetaboutit then when you put it down again, inflate to the recommended preasure.
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02-13-2021, 02:37 PM
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#5
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Senior Member
Name: Gordon
Trailer: 2015 Scamp (16 Std Layout 4) with '15 Toyota Sienna LE Tug
North Carolina
Posts: 5,156
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Quote:
Originally Posted by Jon in AZ
... I’ve honestly never heard of inflating past the maximum sidewall pressure under any circumstances.
..!
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I suspect the 25% over idea comes from this unclear or misleading Goodyear Website where it says:
If the vehicle cannot be put on blocks, follow these steps for tire protection:
...
Inflate tires to recommended operating pressure plus 25%
...
However the keywords are "recommended operating pressure" and not maximum pressure. They are talking about the recommended operation pressure which is lower than the maximum sidewall listed pressure for tires run at less than 100% load (as all tires should be run).
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02-14-2021, 11:37 AM
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#6
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Member
Name: William
Trailer: 13' Perris Pacer
California
Posts: 46
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Removing weight from axle while in storage
"... with weight off of the axle..." Although storing my trailer with weight off the axle makes perfect sense to me, why do I remember reading somewhere that taking weight off the torsion axle could cause internal damage by stretching rubber components designed to be compressed, and by compressing rubber components designed to be stretched. Any insight anyone? Thanks!
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02-14-2021, 01:34 PM
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#7
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Senior Member
Name: bob
Trailer: Was A-Liner now 13f Scamp
Missouri
Posts: 3,209
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my trailer is outside i run my tires at around 35 to 40 i suppose they are right at that! I am not in the camp of blowing tires on my 13 to max! as i travel everything stays where it should in the camper!
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02-14-2021, 04:12 PM
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#8
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Senior Member
Trailer: 2002 19 ft Scamp 19 ft 5th Wheel
Posts: 3,641
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What if I have the tires filled with nitrogen instead of regular air. The nitrogen is susposta be dry. Most of the tire places today are filling with nitrogen. Would I increase the pressure with the tires off the ground?
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02-14-2021, 04:28 PM
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#9
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Senior Member
Trailer: Escape 17 ft
Posts: 8,317
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Quote:
Originally Posted by Darwin Maring
What if I have the tires filled with nitrogen instead of regular air. The nitrogen is susposta be dry. Most of the tire places today are filling with nitrogen. Would I increase the pressure with the tires off the ground?
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From NASA: The air in Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen.
If you were entering Formula One Racing, it might be worth it. You decide.
__________________
What happens to the hole when the cheese is gone?
- Bertolt Brecht
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02-14-2021, 04:49 PM
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#10
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Senior Member
Name: John
Trailer: Escape 21, behind an '02 F250 7.3 diesel tug
Mid Left Coast
Posts: 3,028
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Quote:
Originally Posted by k0wtz
my trailer is outside i run my tires at around 35 to 40 i suppose they are right at that! I am not in the camp of blowing tires on my 13 to max! as i travel everything stays where it should in the camper!
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most FG trailers run 50 PSI for their rated weight... at least my Casita 16 with 14" wheels and Escape 21 with 15" double axle wheels, both are nominially 50 PSI.
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02-15-2021, 05:30 AM
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#11
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Senior Member
Name: Carl
Trailer: 2015 Escape 5.0TA
Florida
Posts: 1,749
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Quote:
Originally Posted by gordon2
I suspect the 25% over idea comes from this unclear or misleading Goodyear Website where it says:
If the vehicle cannot be put on blocks, follow these steps for tire protection:
...
Inflate tires to recommended operating pressure plus 25%
...
However the keywords are "recommended operating pressure" and not maximum pressure. They are talking about the recommended operation pressure which is lower than the maximum sidewall listed pressure for tires run at less than 100% load (as all tires should be run).
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MY COMMENT: That works as long as the recommended operating pressure for the load is at or less than maximum sidewall pressure. I’ve never heard that the maximum sidewall pressure should be exceeded (what does “maximum” infer?). Then again, we are told by many manufacturers to inflate ST tires to 50 psi, and those tires are often inscribed with a maximum sidewall pressure of 50 psi. We are also told to inflate when the tires are cold. So we adjust them to 50 psi in the early morning when it is let’s say 65° F. Then the sun rises high in the sky and the temperature goes up to 85° while we are towing at 60 mph. Check the tire pressure at the next stop and it will be well over 50 psi, especially on the side where the sun is shining. So the maximum sidewall pressure has been exceeded due to rising temperatures and heat related to the friction of rolling along the road.
Quote:
Originally Posted by k0wtz
my trailer is outside i run my tires at around 35 to 40 i suppose they are right at that! I am not in the camp of blowing tires on my 13 to max! as i travel everything stays where it should in the camper!
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MY COMMENT: I do the same thing, Bob. The maximum sidewall pressure of my Goodyear endurance tires is 65 psi. According to Goodyear’s load charts and the scale verified weight of my trailer, I should be inflating them (cold) to 45-50 psi. I inflate them to 50 and things do not bounce around inside the trailer.
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02-15-2021, 07:51 AM
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#12
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Senior Member
Trailer: 2002 19 ft Scamp 19 ft 5th Wheel
Posts: 3,641
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Quote:
Originally Posted by Glenn Baglo
From NASA: The air in Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen.
If you were entering Formula One Racing, it might be worth it. You decide.
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I appoligize for my post. I just did that to have fun. Its a tire so pump it up to the required preasure and forgetaboutit.
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02-15-2021, 08:29 AM
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#13
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Moderator
Trailer: 2009 19 ft Escape / 2009 Honda Pilot
Posts: 6,283
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I am running three trailers right now, my Escape 5.0TA, a fairly large dump trailer and a cargo trailer. They all are inflated to near their maximum pressure all the time, summer or winter, sitting or being towed. This has never been an issue.
__________________
2017 Escape 5.0 TA
2015 Ford F150 Lariat 3.5L EcoBoost
2009 Escape 19 (previous)
“Most folks are about as happy as they make up their minds to be.” — Abraham Lincoln
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02-15-2021, 09:02 AM
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#14
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Senior Member
Name: Gordon
Trailer: 2015 Scamp (16 Std Layout 4) with '15 Toyota Sienna LE Tug
North Carolina
Posts: 5,156
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Quote:
Originally Posted by CPW
...We are also told to inflate when the tires are cold. So we adjust them to 50 psi in the early morning when it is let’s say 65° F. Then the sun rises high in the sky and the temperature goes up to 85° while we are towing at 60 mph. Check the tire pressure at the next stop and it will be well over 50 psi, especially on the side where the sun is shining. So the maximum sidewall pressure has been exceeded due to rising temperatures and heat related to the friction of rolling along the road.
....
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No the maximum inflation specified by the manufacturer has NOT been exceeded just because the PSI reading is higher than 50 (or whatever sidewall says) because the inflation specification is always for "cold" tires and takes into account the rise on pressure that will occur. It could be listed as " XX cold / YY hot" (ex. 50/65) but its not. So if your tires are in storage it MIGHT be OK to go a little over the sidewall pressure but with my TPMS I have seen the pressure and temperature increase from a stationary tire when its in the sunlight, so I would not do it for mounted tires outdoors. The increase from sunlight alone is similar to a rolling tire in the sun so if you start out over the sidewall value, the sunlight will might cause the hot pressure to be more than it should be.
And if tires are removed from the vehicle and not under load, 15 PSI is better.
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02-15-2021, 09:50 AM
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#15
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Senior Member
Name: You can't call me Al
Trailer: SOLD: 1977 Scamp 13'
Massachusetts
Posts: 824
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https://photos.app.goo.gl/fdJ8JrMhq3oWen5U9
Here's what happened when I filled my spare up to 45PSI in MN and drove to MA and left it sit in the sun.
Yeah, it was an old tire, but it still exploded.
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02-15-2021, 12:16 PM
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#16
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Senior Member
Name: Carl
Trailer: 2015 Escape 5.0TA
Florida
Posts: 1,749
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Quote:
Originally Posted by gordon2
No the maximum inflation specified by the manufacturer has NOT been exceeded just because the PSI reading is higher than 50 (or whatever sidewall says) because the inflation specification is always for "cold" tires and takes into account the rise on pressure that will occur. It could be listed as " XX cold / YY hot" (ex. 50/65) but its not. So if your tires are in storage it MIGHT be OK to go a little over the sidewall pressure but with my TPMS I have seen the pressure and temperature increase from a stationary tire when its in the sunlight, so I would not do it for mounted tires outdoors. The increase from sunlight alone is similar to a rolling tire in the sun so if you start out over the sidewall value, the sunlight will might cause the hot pressure to be more than it should be.
And if tires are removed from the vehicle and not under load, 15 PSI is better.
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That is NOT the point I was making. I DID NOT say or imply tires become unsafe in the heat, and I am fully aware that pressures will vary throughout any given day that the tire is in use. We could get into a discussion of the maximum amount of pressure that any given wheel can handle but that would be an entirely different topic. I was simply stating that when heat and friction causes a tire inflated to its maximum sidewall pressure when cold to rise above its maximum sidewall pressure the tire’s psi is higher than its maximum sidewall pressure at that moment, regardless of what the manufacturer takes into account. If the maximum sidewall pressure is 50 psi and heat and friction cause it to increase even one the psi to 51 psi, then at that moment it is inflated above its maximum sidewall pressure. Last I checked 51 is greater than 50. If you inflate it to 51 psi when it is “cold,” you have exceeded the maximum sidewall pressure even if you do not run it down the road. And, if a sudden cold wave occurs (dropping 50° overnight as sometimes happens in places like Denver), the “overinflated” tire would likely then be inflated below its the maximum sidewall pressure in the morning, That is why it is a good idea to frequently check tire pressure and adjust accordingly to prevailing temperatures. My tire inflated to 50 psi in Florida at 90° F contains far fewer gas molecules than Joe Blow’s tire inflated to 50 psi in Fairbanks when it is 50° below zero, yet both are inflated to 50 psi.
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02-15-2021, 04:09 PM
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#17
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Senior Member
Name: Gordon
Trailer: 2015 Scamp (16 Std Layout 4) with '15 Toyota Sienna LE Tug
North Carolina
Posts: 5,156
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Quote:
Originally Posted by CPW
.. I DID NOT say or imply tires become unsafe in the heat, ..
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And no one said or implied that you had.. but you missed my point.
Quote:
Originally Posted by CPW
....So the maximum sidewall pressure has been exceeded due to rising temperatures and heat related to the friction of rolling along the road.....
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But to be correct, the maximum sidewall pressure has not been exceeded because the maximum tire pressure is not just a number on the sidewall (i.e. 50)... it is a number in a mathematical relationship known as Gay-Lussac's Gas Law. Of course the sidewall does not show the mathematical formula between the maximum (cold) inflation and temperature but it is part of the engineering and design and the reason that the tire also has a temperature rating. So just because the sidewall says 50 PSI and going down the road the tire heats up and the PSI is 62, that does not mean that the listed maximum pressure limit (which is 50 when cold) has been exceeded unless you also exceed the tire's temperature rating. Only part of the unshown but very relevant formula has changed.
This might sound like manushia but it is important to understand that a warm tire can and will read pressure higher than the sidewall number but still be under the max inflation listed on the tire because it is not cold. The max inflation number on the sidewall is only valid and correct when the tire is cold. It is important because some people have measured the pressure when the tire was warm, found it high, and then let some air out to reach the sidewall number. Then they end up with an underinflated tire and resulting tire damage or failure.
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02-15-2021, 04:52 PM
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#18
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Senior Member
Trailer: Escape 17 ft
Posts: 8,317
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What temp is cold?
__________________
What happens to the hole when the cheese is gone?
- Bertolt Brecht
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02-15-2021, 05:25 PM
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#19
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Senior Member
Name: Gordon
Trailer: 2015 Scamp (16 Std Layout 4) with '15 Toyota Sienna LE Tug
North Carolina
Posts: 5,156
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Quote:
Originally Posted by Glenn Baglo
What temp is cold?
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Cold is the outdoor temperature in the morning before the sun comes out and before any drastic climate changes occur (such as driving from your place to mine, maybe 1,000 miles south). Typical daily temperature variations are usually not a concern but in extreme cases might be.
In cases where there are large climatic temperature changes readjust in the morning or consider that for every 10° fluctuation in outdoor temperature (up or down), tires will go up or down by about 1 psi. Adjust accordingly.
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02-15-2021, 05:28 PM
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#20
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Senior Member
Name: Steve
Trailer: 2018, 21ft escape— 2019 Ram 1500 Laramie
NW Wisconsin
Posts: 4,500
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Quote:
Originally Posted by Glenn Baglo
What temp is cold?
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We had -32 deg F this morning , my brother who lives 30 miles North of us had -34 deg F this morning.
The winds this morning were calm so technically we were just on the edge of cold
Spent part of the morning shoveling snow and enjoying a cigar .
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