Go Back   iRV2 Forums > TRAVEL TRAILER, 5th WHEEL & TRUCK CAMPER FORUMS > 5th Wheel Discussion
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 08-31-2012, 06:02 PM   #1
Junior Member
Join Date: Aug 2012
Posts: 1
Tires and Wheels

I have a 2007 28' Rockwood 5th wheel with tire sizes for 15" wheels 205/75/15 load rate C (50PSI). I need new tires and would like to upgrade to a D load tire wich will carry a heavier load. What is the best make of tires for this application considering increased air pressure for my mag wheels? Do I have to go to 16" wheels? Would they even fit my RV? How about going into a LT tire? I am looking forward to some answers to my questions.

pitch is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 08-31-2012, 06:45 PM   #2
Senior Member
Join Date: Apr 2004
Posts: 1,171
Your ST205/75-15 C has 1820 lbs of capacity x 4 = 7280 lbs for a tandam axle trailer.

If it was my trailer I would look into mounting Goodyear Wrangler H/T or a commercial grade Maxxis U-168 A LT215/75-15 D at 2095 lbs. Both tires require a 65 psi rated wheel and are popular with trailering public.

Also there are many usa branded LT235/75-15 C at 1985 lbs capacity . They are a bit taller so you will have to do your own measuring for proper wheelwell clearance issues.

I notice the Yokohama RY215 in a 700R-15 load range D at 2040 lbs are popular with the boat trailering crowd.

Any 16" (2680-3042 lb capacity) IMO would be overkill for a trailer that needs 1820 lb per tire. Trailer tire operate in a extreme invironment and work best with max pressures unlike a tow vehicle.

'03 Dodge 2500 Cummins HO 3.73 NV5600 Jacobs
'98 3500 DRW 454 4x4 4.10 crew cab
'97 Park Avanue RK 28' 2 slides
JIMNLIN is offline   Reply With Quote
Old 09-01-2012, 02:53 PM   #3
Senior Member
FastEagle's Avatar
Join Date: Sep 2009
Posts: 901
If your rims have the load capacity and pressure ratings for the increased pressure of the LRD tires they would be your most economical upgrade. They are identical in size insuring easy fitment.

In the reference you can compare sizes and load capacities. The reference is not an endorsement for that brand of tires. Itís just what it is, an informational reference.


FastEagle is offline   Reply With Quote
Old 09-02-2012, 12:31 PM   #4
Senior Member
Sandman's Avatar
Coastal Campers
Join Date: Feb 2000
Location: Fairfax, VA
Posts: 202
Another option is the Continental Vanco2 LT225-70-R15D 27.4 in high (vs 27.1 for 205-75) 9in wide vs 8in (1/2 ib each side this would be the measure and remeasure for me) 2470lb at 65psi..

I run 80psi tires on stock wheels, trailer came with 65psi tires.. no pressure related problems in 3 years.. with all of the 15in ST tire (China Bombs) issues on the RV boards, when was the the last time you read about a rim failure? (I do run all steel valve stems)
I will be trying the Continental LTs when my lstill new Carlisles separate.
Jeanie & Joe

2006 "Collector Edition" Arctic Fox 24-5N
Sandman is offline   Reply With Quote
Old 09-02-2012, 03:06 PM   #5
Moderator Emeritus
SmokeyWren's Avatar

Join Date: Jun 2011
Location: Midland County, Texas
Posts: 3,585
Originally Posted by pitch View Post
I have a 2007 28' Rockwood 5th wheel with tire sizes for 15" wheels 205/75/15 load rate C (50PSI).
Typical. Not enough extra tire weight capacity for that much trailer.

My 5er came with those same tires. And the 5.5" wide wheels that were okay for those tires but not for the ST225/75R15 I wanted. So after blowing out two tires on the first trip, I bought new wheels that were 6" wide:

The bigger tires on wider rims fit inside the wheel wells of the trailer with rubbing only if I hit a really severe bump. So don't hit any really severe bumps!

I went with Maxxis ST225/7R15D tires. No more trailer tire troubles. Maxxis makes ST225/75R15E trailer tires too, but I didn't need more than the load range D.

If your careful measurements convinces you that you don't have room for ST225/75R15 on 6" wde rims, then back off to ST205/75R15D on your stock rims. Those have 2150 pounds weight capacity @65 PSI, which is a lot more than you have now.
M8008 ST Radial

The Power King Tomaster tires that FastEagle linked to are the famous "China bombs" that a lot of folks complain about. I don't have any experience with those, but I have Maxxis ST225/75R15E on my cargo trailer and Maxxis ST 225/75R15D on my 5er, with no complaints.

My new TT came with more than enough tire weight capacity for the trailer (7,000 pounds tire capacity vs. about 5,000 pounds max load on the tires). But I'll still probably replace them with more tire when the first one of the stock Marathon ST205/75R14 tires blows. I have over 5,000 miles on those tires now with no problems, so maybe Goodyear has figured out how to build a trailer tire that won't blow up on the first long high-speed trip.
Grumpy ole man with over 50 years towing experience. Now my heaviest trailer is a 7,000-pound enclosed cargo trailer, RV is a 5,600 pound Skyline Nomad Joey 196S, and my tow vehicle is a 2012 F-150 3.5L EcoBoost SuperCrew.
SmokeyWren is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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

» Featured Campgrounds

Reviews provided by

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 08:24 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.