Reply
 
Thread Tools Display Modes
Old 04-04-2015, 03:02 PM   #21
Senior Member
 
Join Date: Mar 2015
Location: Alabama
Posts: 189
kraftengr; you are thinking clearly, congrats on your purchase. Sounds like you may have an E load range tire, I believe those are typically 80 psi and ten ply. Hopefully its not just a bias ply but a radial. Even so, most people recommend tires that will, at minimum, load 15-20% of the maximum loaded value they ever tend to carry. In my case, I prefer this to be my GAWR divided by 2 since I will never exceed GAWR

For example my tandem axles are rated at 4K each. The combined weight on the axles is 7800 lbs hitched to the vehicle (that is with a weight distributing hitch transferring some load back to the axles). You won't have to worry about that. So theoretically 7800 lbs divided by 4 tires on the tandem axles equals 1950 lbs of continuous weight per tire. Now, to accommodate swerves, potholes, uneven surfaces, debris, etc I prefer to have an extra 20% of weight margin in those tires. So add 20% to 1950 and that comes to an extra 390 lbs per tire for those common temporary tire stress situations. So 1950 plus 390 equals 2340 lbs. The next higher load range tire is a D range in my size (15 inch 225/75) which is rated at 2540 lbs. That's the way I determine with 60-65 psi for even wear. Too stiff a tire can be hard on your cargo and your axles, so that's why excessive overkill can be detrimental long term on stiffness and over pressuring at light loads. This has been debated many times but is only my humble opinion and personal research. I respect the views of others. Go make some lasting camping memories. There are the nicest people to meet out there!

Sadly the manufactures install minimal quality and minimal load bearing tires which is why so many pre-mature tire failures occur. Those posts are all over this website. For the Windjammer it was a cheap china bomb Load Range C 2150 lb tire 3 of 4 defective.
__________________

__________________
2014 Windjammer 3025W Diamond 34.5 ft 8300 lbs.
2010 F150 SC XLT 4x4 5.4L, 3.55 gears 20" rims
12 k Equalizer WDH, Firestone Airbags, HD Bilsteins
TST 507RV TPMS
Zolin is offline   Reply With Quote
Old 04-04-2015, 03:05 PM   #22
Senior Member
 
Long Leaf Piners's Avatar
 
Join Date: Jun 2014
Location: Durham, NC
Posts: 109
Quote:
Originally Posted by grumpyer View Post
So now I have a question!
If sticker on TT states 50psi max. and Class c tires are being used they too are marked on sidewall at 50 psi
What happens when you upgrade to D range and 65 psi max?
.....same load on TT. Do you run at
50 psi or 65 psi. No I'm not trying to be a smart ass!
Quote:
Originally Posted by OldCoot View Post
No battle here, I just stated what I do and prefer. Naturally, you are free to do whatever you so desire.
Quote:
Originally Posted by Oakman View Post
For trailer tires, Iím in the camp with the ďinflate to the maxĒ folks. Iíve never had any issues with the ST tires that were on the fifth wheels Iíve owned. Iím on my third fifth wheel and Iíve been RVing since 2003.
We, too, have had three rigs since 2005 when we switched to wheeled camping. And I agree with Old Coot and Oakman--even as we are getting ready to upgrade the tires on our 2014 fifth. Running with TST pressure monitoring, we've had no trouble with the stock tires, but I want to upgrade from C-Load to D-Load.
And to get to Grumpyer's question, we will be upping our TP from 50 (on c-loads) to 65 on the new D-loads. (used to run another fifth on E-loads at 80 lbs, and it was great for thousands of miles. Over-flexing sidewalls through low TP seems a sure fire problem.
BTW, OC is right--we have yet to see a tread-wore-out trailer tire: cracked and replaced- yup; but (like OC and Me) Not worn out.
__________________

__________________
2014 8528 IKWS
Ford F-250 Diesel
Cricket the Cairn and Sally the Terrier Muppet Mix
Long Leaf Piners is offline   Reply With Quote
Old 04-04-2015, 03:10 PM   #23
Senior Member
 
GreenImp's Avatar
 
Join Date: Jul 2013
Location: Oregon
Posts: 620
Send a message via MSN to GreenImp
Quote:
Originally Posted by grumpyer View Post
So now I have a question!
If sticker on TT states 50psi max. and Class c tires are being used they too are marked on sidewall at 50 psi
What happens when you upgrade to D range and 65 psi max?
.....same load on TT. Do you run at
50 psi or 65 psi. No I'm not trying to be a smart ass!

Not sure if you simply mistyped or not, but the sticker on the TT represents a MINIMUM PSI as opposed to the tire sidewall listing the MAXIMUM PSI. You must be somewhere between those at all times.

Personally, my trailer states a minimum of 50, my tires (upgraded from original) state a maximum of 65, and I am running at 55 currently.
__________________
'04 GMC Sierra 2500HD, CCSB, D/A, MaxBrake, B&W Companion, Retrax Pro, AR Power Steps
2013 Rockwood 8289WS w/Diamond pkg
1969 Camaro RS/SS Convertible
Dad's old 1968 Empi Imp (recently recovered from under 21 years worth of boxes/dust)
GreenImp is online now   Reply With Quote
Old 04-04-2015, 03:21 PM   #24
Mod free 5er
 
Join Date: Mar 2008
Location: Concord, NC
Posts: 24,215
Quote:
Originally Posted by GreenImp View Post
...Personally, my trailer states a minimum of 50, my tires (upgraded from original) state a maximum of 65, and I am running at 55 currently.
That's what it's all about, you pay for the tires and therefore you can run whatever pressure you want. I just prefer max cold pressure of 65# for LR D. Been pulling rv trailers since 1975 and only had one blowout on the 08Flagstaff running LR C factory tires at 50 psi and had $1800 damage.
__________________
OldCoot is offline   Reply With Quote
Old 04-04-2015, 03:30 PM   #25
Senior Member
 
Join Date: Mar 2015
Location: Alabama
Posts: 189
If ever in question, I always load a TT to its max psi. I actually do this anyway on my boat, airplane, and lawnmower. That avoids over-stress flexing and keeps temps down. I had a long discussion about this with a Goodyear specialist at corporate after I blew a Marathon. He went into a lot of technical detail but in the end suggested always inflating to max psi stamped on tire (for ST trailer tires, that is). If upgrading load range from placarded I would personally ignore the placard and go with the tire stamping guidelines, if ever in doubt. For precision, if one wants to go the trouble of weighing and interpolation tables then consult the manufacturers recommendation. D range tires are typically 65 psi and E range are typically 80 psi.
__________________

__________________
2014 Windjammer 3025W Diamond 34.5 ft 8300 lbs.
2010 F150 SC XLT 4x4 5.4L, 3.55 gears 20" rims
12 k Equalizer WDH, Firestone Airbags, HD Bilsteins
TST 507RV TPMS
Zolin is offline   Reply With Quote
Reply

Tags
pressure, tire

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



» Virginia Campgrounds

Reviews provided by




ForestRiverForums.com is not in any way associated with Forest River, Inc. or its associated RV manufacturing divisions.


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 03:30 AM.