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01-25-2020, 07:38 PM
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#1
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Senior Member
Join Date: Nov 2019
Location: Frisco, TX & Colorado Springs, CO
Posts: 530
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Tire Opinions (with data)
Hi Everyone.
We read nearly all tire pressure threads in the forum. The consistent element is the recommended tire pressure can be determined only if you have a four corner weight and the tire manufacturers recommendation chart. So we now have both.
What has stopped us in our tracks was how referencing the numbers calls for a pressure that is “much lower” than we are currently running (90 psi in front and 95 psi on rear). So, we thought we would share our numbers with all of you since many of you have significantly more experience on this topic.
Based on our numbers below and the manufacturer chart (also below), what is your opinion.
Thanks in advance!
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01-26-2020, 11:50 AM
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#2
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Senior Member
Join Date: Aug 2015
Location: Media, PA
Posts: 2,930
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Make sure you keep the pressure the same on all tires on the same axle. If one side is heavier you use that as your set point if I understood the concept correctly.
__________________
2017 Dynamax REV 24RB
2018 Ford F-150
Formerly a 2013 Sunseeker 2250 SLEC.
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01-26-2020, 12:03 PM
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#3
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Senior Member
Join Date: Nov 2019
Location: Frisco, TX & Colorado Springs, CO
Posts: 530
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Quote:
Originally Posted by Delco Bobby
Make sure you keep the pressure the same on all tires on the same axle. If one side is heavier you use that as your set point if I understood the concept correctly.
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Thanks Delco Bobby. We’ve installed Crossfirea which should help with this as well.
Any thoughts on what you would run the pressure at based on the numbers?
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01-26-2020, 08:02 PM
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#4
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Senior Member
Join Date: Aug 2015
Location: Media, PA
Posts: 2,930
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Quote:
Originally Posted by EdandShelley
Thanks Delco Bobby. We’ve installed Crossfirea which should help with this as well.
Any thoughts on what you would run the pressure at based on the numbers?
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90 front
78 to 80 rear. Since you mention you must have duel rear wheels.
I am looking at this on a small screen so hopefully I read the chart correctly.
__________________
2017 Dynamax REV 24RB
2018 Ford F-150
Formerly a 2013 Sunseeker 2250 SLEC.
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01-29-2020, 09:16 AM
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#5
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Senior Member
Join Date: Aug 2017
Location: Franktown, Colorado
Posts: 939
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Quote:
Originally Posted by EdandShelley
Hi Everyone.
We read nearly all tire pressure threads in the forum. The consistent element is the recommended tire pressure can be determined only if you have a four corner weight and the tire manufacturers recommendation chart. So we now have both.
What has stopped us in our tracks was how referencing the numbers calls for a pressure that is “much lower” than we are currently running (90 psi in front and 95 psi on rear). So, we thought we would share our numbers with all of you since many of you have significantly more experience on this topic.
Based on our numbers below and the manufacturer chart (also below), what is your opinion.
Thanks in advance!
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What PSI are you currently running that 90 and 95 are "much lower"? Your axle/wheel weights are identical to mine. I run 85 front and 95 in the rear duals which gives me the best ride and proper pressure when towing.
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01-29-2020, 09:30 AM
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#6
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Senior Member
Join Date: Feb 2017
Location: SW Ohio
Posts: 1,670
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From the chart it looks like 70PSI is the lowest recommended and still way more then needed. i would go 70-75PSI
__________________
Almost not an SOB
Artic Fox 3018 5th Wheel - on order
Grand Design 2800BH TT 2021
Prior TT 2017 Flagstaff 831CLBSS Classic Ultra lite - SOLD 5/21
TV 2024 F350 DRW - on order
TV 2017 F150 6.5' bed 3.5 Eco-boost Max tow 1800lbs payload
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01-29-2020, 09:45 AM
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#7
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Senior Member
Join Date: Aug 2017
Location: Franktown, Colorado
Posts: 939
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Quote:
Originally Posted by llr
From the chart it looks like 70PSI is the lowest recommended and still way more then needed. i would go 70-75PSI
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You're not reading the chart correctly. Total front axle weight is 10,400. That is the weight you use to determine psi on the front. You use total axle weight for the rear too except use the "dual" numbers. Also, when the rig was weighed if it was not full of fuel, water and your normal load of people and stuff, you have to account for that. If you tow a trailer you also have to account for the tongue.
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01-29-2020, 10:27 AM
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#8
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Senior Member
Join Date: Jun 2016
Posts: 5,033
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Hopefully Tireman9 will chime in on this.
My understanding is that the inflation tables show psi/load requirements PER TIRE. So I think LLR is correct. Note that you use the pressure requirement for the tire carrying the largest load per axle.
On my trailer, max load per tire is 2540 lbs or 5080 per axle, this is at 65 psi. So, at 65 psi the tire can carry 2540 lbs. They don't publish a pressure to carry 5080 lbs. I have two axles so total load is 10160 lbs. This makes sense because my actual trailer weight is ~7000 lbs.
__________________
Al
I am starting to think, that I will never be old enough--------to know better.
Tolerance will reach such a level that intelligent people will be banned from thinking so as not to offend the imbeciles. Fyodor Mikhailovich Dostoevsky, Russian Novelist
S.E. Mich. Flagstaff 26FKWS / 2022 F-150 3.5 EcoBoost SCrew Propride
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01-29-2020, 11:19 AM
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#9
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Senior Member
Join Date: Jan 2017
Location: KS
Posts: 2,369
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I am learning and only have a question for you.
Are you trying to lower them from max to alleviate ride issues for your MH?
I have a TT so I set mine at max to put less flex in the tire.
On my truck I will adjust based on if I am towing or not to improve the ride when not towing. I dont care how rough the ride is when towing because it needs to haul the weight even if there is plenty of room from the loading chart so I set them to max cold pressure.
Just wanting to understand what you are doing and if my logic is flawed. Thanks!
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01-29-2020, 12:14 PM
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#10
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Senior Member
Join Date: Feb 2017
Location: SW Ohio
Posts: 1,670
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Quote:
Originally Posted by RV Randy
You're not reading the chart correctly. Total front axle weight is 10,400. That is the weight you use to determine psi on the front. You use total axle weight for the rear too except use the "dual" numbers. Also, when the rig was weighed if it was not full of fuel, water and your normal load of people and stuff, you have to account for that. If you tow a trailer you also have to account for the tongue.
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That is possible but I have not seen a chart be per axle before, I have not seen one add the duals together, they have been per tire with a lower per tire if used in a dual configuration. I don't see where the chart specifies if it is per axle or tire.
It does look like that chart is per axle, I found a Michelin chart that specifies per axle end and has numbers about half
https://www.rvsafety.com/images/pdf/...ionrvtruck.pdf
__________________
Almost not an SOB
Artic Fox 3018 5th Wheel - on order
Grand Design 2800BH TT 2021
Prior TT 2017 Flagstaff 831CLBSS Classic Ultra lite - SOLD 5/21
TV 2024 F350 DRW - on order
TV 2017 F150 6.5' bed 3.5 Eco-boost Max tow 1800lbs payload
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01-29-2020, 12:36 PM
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#11
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Senior Member
Join Date: Nov 2012
Posts: 578
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Quote:
Originally Posted by dbledan
I am learning and only have a question for you.
Are you trying to lower them from max to alleviate ride issues for your MH?
I have a TT so I set mine at max to put less flex in the tire.
On my truck I will adjust based on if I am towing or not to improve the ride when not towing. I dont care how rough the ride is when towing because it needs to haul the weight even if there is plenty of room from the loading chart so I set them to max cold pressure.
Just wanting to understand what you are doing and if my logic is flawed. Thanks!
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A few might disagree, but I think the consensus by pretty much all who understand TRAILER tires agree that you always inflate them to the max cold sidewall pressure. There are a few who think the tire industry is wrong to even have TRAILER tires. They say you should not use trailer tires on trailers. I won't comment on that, but I will say if you do have a trailer and use TRAILER tires, you really can't go wrong with using the sidewall specified max cold pressure.
I have views on MH & Truck tires, but I'll leave that to others.
__________________
2006 FR Salem 32SRV-LE 5th Wheel Toy-Hauler
2006 F250 Superduty 6.0 Lariat 4x4 Off Road
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01-29-2020, 12:59 PM
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#12
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Senior Member
Join Date: Jul 2017
Location: California
Posts: 7,616
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Quote:
Originally Posted by Slow Moon
A few might disagree, but I think the consensus by pretty much all who understand TRAILER tires agree that you always inflate them to the max cold sidewall pressure. There are a few who think the tire industry is wrong to even have TRAILER tires. They say you should not use trailer tires on trailers. I won't comment on that, but I will say if you do have a trailer and use TRAILER tires, you really can't go wrong with using the sidewall specified max cold pressure.
I have views on MH & Truck tires, but I'll leave that to others.
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You do realize this is a Motorhome right?
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01-29-2020, 01:36 PM
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#13
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Senior Member
Join Date: Jan 2019
Location: North Port Florida
Posts: 2,050
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watching .... thanks
__________________
Frank & Cindy--- (SOB) 5th Wheel ---2019 Ram 3500 Cummins 6.7 SRW 4x4 8' bed--- Payload 4394------Remi & Sage camping pups---TST 507 TPMS ... B&W Patriot 18K---3.73 axle ... Predator 3500---2019 48 days ---2020 28 days Camping
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01-29-2020, 02:05 PM
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#14
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Senior Member
Join Date: Nov 2012
Posts: 578
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Quote:
Originally Posted by babock
You do realize this [sic] is a Motorhome right?
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Perhaps you missed the quote to which I responded. It included a question involving dbledan's TT & Truck (NOT a MH). It said, in part, "I have a TT so I set mine at max to put less flex in the tire," and asked if his logic was flawed.
My response supported dbledan's logic as to TT tires. I clearly made a distinction between the TT tire issue as opposed to Truck/MH tire issues, avoiding any comment on the latter.
Given that the question directly related to TT tires, and I limited my answer to Trailer tires, I anticipated flak from the "never ST" crowd. I didn't expect this flak that I'm not supposed to talk about trailer tires. Live and learn.
__________________
2006 FR Salem 32SRV-LE 5th Wheel Toy-Hauler
2006 F250 Superduty 6.0 Lariat 4x4 Off Road
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01-29-2020, 02:17 PM
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#15
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Senior Member
Join Date: Jul 2017
Location: California
Posts: 7,616
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Quote:
Originally Posted by Slow Moon
Perhaps you missed the quote to which I responded. It included a question involving dbledan's TT & Truck (NOT a MH). It said, in part, "I have a TT so I set mine at max to put less flex in the tire," and asked if his logic was flawed.
My response supported dbledan's logic as to TT tires. I clearly made a distinction between the TT tire issue as opposed to Truck/MH tire issues, avoiding any comment on the latter.
Given that the question directly related to TT tires, and I limited my answer to Trailer tires, I anticipated flak from the "never ST" crowd. I didn't expect this flak that I'm not supposed to talk about trailer tires. Live and learn.
But I degrees....the topic of the thread is motor-home tires.
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BTW, the consensus is far from maxing out the PSI in trailer tires. In fact Tireman9, the expert in the group, specifically says you don't.
Back to the original topic of PSI for Motor Home tires!
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01-30-2020, 02:04 AM
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#16
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Senior Member
Join Date: Nov 2012
Posts: 578
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Quote:
Originally Posted by babock
BTW, the consensus is far from maxing out the PSI in trailer tires. In fact Tireman9, the expert in the group, specifically says you don't.
Back to the original topic of PSI for Motor Home tires!
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NOT SO FAST!
Do you have a citation to support what you have said about Tireman9?
Here are actual quotes of Tireman9, my most trusted tire information source, saying the opposite of what you tell us:
“…for Tandem and triple axle trailers I strongly recommend that the tire cold inflation be set to the inflation molded on the tire sidewall associated with the tire maximum load capacity.” RV Tire Safety: Tire inflation not the same for all trailers
“So the best recommendation I can give to trailer owners is to run the inflation molded on the tire sidewall.”
RV Tire Safety: "Interply Shear" and other Techno Babble
“RV Trailers place different loading on the radial belts than motorized vehicles. This Interply Shear can be 24% higher than seen on tires on the tow vehicle. This is a primary reason for shorter tire life in trailer application.
To get the Interply Shear lower, you should use the pressure molded on the tire sidewall as your daily "Set" pressure. 07-01-2019, 08:48 PM
http://www.forestriverforums.com/for...-187940-3.html
“towed vehicles such as trailers *** [suffer from] “Interply Shear” which is a technical term for the forces in the tire structure that are trying to tear the tire belts off the body of the tire. The best way to lower, but not eliminate, the Interply Shear is for trailers to use the max inflation molded on the tire sidewall as the cold tire inflation.”
https://blog.coach-net.com/2016/06/0...ntials-part-1/
If Tireman9 has changed his position, it would be good for all of us to know where we can find that information.
Finally, IT IS NOT NICE TO MISQUOTE!
In the quote you attributed to me, your words have been inserted: "But I degrees[sic]....the topic of the thread is motor-home tires." Those are not my words and I do not appreciate them appearing in a quote purporting to be of me.
Thank You
__________________
2006 FR Salem 32SRV-LE 5th Wheel Toy-Hauler
2006 F250 Superduty 6.0 Lariat 4x4 Off Road
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01-30-2020, 04:00 AM
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#17
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Senior Member
Join Date: Jan 2019
Location: North Port Florida
Posts: 2,050
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Quote from Tireman9 "Bottom line
In a number of posts I have recommended that Motorhomes set their inflation based on measured static load plus a margin of at least 10% additional PSI. This would also apply to single axle trailers. BUT for Tandem and triple axle trailers I strongly recommend that the tire cold inflation be set to the inflation molded on the tire sidewall associated with the tire maximum load capacity. I also recommend that the measured static tire loads on these trailers be no greater than 85% of the tire maximum with a 20% margin being better." this quote applies to Trailer Tires not Motor homes ... OP has Motorhome ....
__________________
Frank & Cindy--- (SOB) 5th Wheel ---2019 Ram 3500 Cummins 6.7 SRW 4x4 8' bed--- Payload 4394------Remi & Sage camping pups---TST 507 TPMS ... B&W Patriot 18K---3.73 axle ... Predator 3500---2019 48 days ---2020 28 days Camping
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01-30-2020, 11:17 AM
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#18
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Senior Member
Join Date: Nov 2012
Posts: 578
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Quote:
Originally Posted by frank4711
Quote from Tireman9 "Bottom line
In a number of posts I have recommended that Motorhomes set their inflation based on measured static load plus a margin of at least 10% additional PSI. This would also apply to single axle trailers. BUT for Tandem and triple axle trailers I strongly recommend that the tire cold inflation be set to the inflation molded on the tire sidewall associated with the tire maximum load capacity. I also recommend that the measured static tire loads on these trailers be no greater than 85% of the tire maximum with a 20% margin being better." this quote applies to Trailer Tires not Motor homes ... OP has Motorhome ....
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Thank You Frank,
Your Tireman9 quote is from Feb 22, 2018 and is the same as my first Tireman9 quote above. Tireman9 says the same thing at least as late as 07-01-2019, 08:48 PM (my third quote above). I'm waiting to see if babock will show us where Tireman9 has changed his position.
__________________
2006 FR Salem 32SRV-LE 5th Wheel Toy-Hauler
2006 F250 Superduty 6.0 Lariat 4x4 Off Road
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01-31-2020, 12:36 AM
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#19
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Senior Member
Join Date: Jul 2017
Location: California
Posts: 7,616
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Quote:
Originally Posted by Slow Moon
NOT SO FAST!
Do you have a citation to support what you have said about Tireman9?
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Quote:
Originally Posted by Slow Moon
Thank You Frank,
Your Tireman9 quote is from Feb 22, 2018 and is the same as my first Tireman9 quote above. Tireman9 says the same thing at least as late as 07-01-2019, 08:48 PM (my third quote above). I'm waiting to see if babock will show us where Tireman9 has changed his position.
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Ask and you will receive! LOL.
Go to post 100
From December 6, 2109
In his example, he is saying to inflate a load range D(Max PSI 65) to 55 PSI.
http://www.forestriverforums.com/for...198414-10.html
Here is another from his web page:
RV Tire Safety: Inflation
BTW, there are inflation tables based on load for ST tires for a reason.
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01-31-2020, 01:11 AM
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#20
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Senior Member
Join Date: Jul 2017
Location: California
Posts: 7,616
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Quote:
Originally Posted by Slow Moon
Finally, IT IS NOT NICE TO MISQUOTE!
In the quote you attributed to me, your words have been inserted: "But I degrees[sic]....the topic of the thread is motor-home tires." Those are not my words and I do not appreciate them appearing in a quote purporting to be of me.
Thank You
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I was skiing while I was typing on my phone. I was wondering where that text got put!!!! LOL
Back to the Motor Home discussion!!!!
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