My Wheel and Tire Upgrade (Sorry but Long)

[Poppy's 5th Wheel]

Well, I've mentioned here before that I am one of the lucky ones with zero tire problems from my original Power King tires. After 2 years and over 10,000 miles a couple have started showing some wear on the outside shoulders from scrubbing in tight turns so I decided to replace them. I decided to move from 15s to 16s for all the reasons mentioned in many other threads.

I ordered new aluminum wheels from trailertiresandwheels.com (who were fantastic to work with BTW) plus a steel for the spare. All 5 wheels delivered for around $500. I then decided on Sailun tires. I was so excited about these tires based on all I had read. My local Big O Tire was able to get them at $160apiece. They all arrived within a week and my tire store mounted and balanced them. As soon as I saw them I know I had made a big mistake. These are huge (diameter), heavy tires. I tried them on anyway and my fear was realized, way too big for my trailer.

I was very fortunate that my tire store owner was very willing to work with me and arranged to have the tires dismounted and returned with no restocking fees! We then reviewed many other tires and, after consulting with the folks at trailertiresandwheels.com as well, choose Big O's own Big Foot H/T in a 225/75R 16/E. A great LT tire (rated at 3,042 lbs) which will easily support the weight of my trailer (about 10,000 loaded). Tires also come with Big O's 3 year warranty.

Anyway, put them on the trailer yesterday and they fit perfectly and I am very pleased. Here's a few pictures. First 2 pictures are the Sailuns mounted. I would still recommend these tires for anyone who has the room.

[Poppy's 5th Wheel]

A couple more shots

[tileman]

Good luck with your new tires.
Just had to replace all 4 of mine from last weeks 2 blowouts

We went with the Maxxis M8008 they look nice just hope they hold up

[CWtheMan]

You should look on your new tires sidewalls to confirm their load capacity. The load range/load index for the LT225/75R16E is set at 2680# at 80 psi. Unless that is some sort of hybrid tire that's going to be its maximum load capacity.

CW

[Poppy's 5th Wheel]

Even so, my trailer weighs just under 10,000 full to travel. Subtract the weight on the king pin and I'm well under the weight limits. The original Power King tires were rated at 2,440 @ 65 psi.

Thanks for pointing that out though.

BTW, tires are made in the USA. Here's info from the spec sheet:

Features:
•Heavy Duty Tread for Extended Life
•Even Load Distribution Ensures Consistent Traction
•Supports Loads Up To 3,042 lbs. Per Tire

Benefits:
•Long wearing.
•Great highway stability.
•Industrial strength.

Warranty: Big O 3 Year

[CWtheMan]

I already looked at the spec sheet. When you click on the tire specs block it lists a load index of 115. A 3042# LRE has a load index of 120. I think they just put in the wrong load capacity (3042#).

http://www.bigotires.com/Tire-Detail...FOOT-H-T/12602

Anyhow, when you set a new recommended tire pressure you will want to use the load chart for the 2680# tire. The tire pressure for your new tires should be set to the load capacity of your OE tires (2540#).

CW

[jadatis]

For the new pressure advice you can use my made motorhome tire-pressure calculator. Can be found in next map on my skydrive that belongs to my hotmail adress with same username as here ( combine yourselfes , spamm macines cant this way). With this one for motorhome you can play more with the reserves and even can give seperate wheel weights in part 3 .
But I also made a Traveltrailer-tirepressure-calculator . will give both links to the maps, but you can navigate my complete public map like is done in a forum.

To use a spreadsheet you first have to download it to your computer by RIGHTCLICKING and then choose DOWNLOAD from the dropdownbox. Dont use leftclicking or open in WEB-app or EXCELL , goes wrong or to complicated.After download and eventual virus-check ( you never know with those duch foreigners) open it in Excell programm on your computer, but Open Office CALC can handle it too.

I espect a higher pressure for the same load then the D-load , so if you kept them to 65 psi the E-load need probably about 70 psi to be yust as save for the tires, and your old tires proved to have a save pressure.
Wear on the outside can also mean a uninteded camber angle or alighnment with tires pointed in or outside seen from above ( dont know the English word from above /-\ or \-/).


Here the links to the maps , but if you cant handle it , give the details ( here only of tires needed maximum load written from sidewall+ speedcode ), and I will do it for you and give a picture of the filled in spreadsheets.
To the motorhome calculator
https://skydrive.live.com/?cid=a526e...E092E6DC%21793

And to the traveltrailer calculator
https://skydrive.live.com/?cid=a526e...E092E6DC%21348
and a picture of the traveltrailer calculator to show the meaning

[CWtheMan]

Originally Posted by jadatis

For the new pressure advice you can use my made motorhome tire-pressure calculator. Can be found in next map on my skydrive that belongs to my hotmail adress with same username as here ( combine yourselfes , spamm macines cant this way). With this one for motorhome you can play more with the reserves and even can give seperate wheel weights in part 3 .
But I also made a Traveltrailer-tirepressure-calculator . will give both links to the maps, but you can navigate my complete public map like is done in a forum.

To use a spreadsheet you first have to download it to your computer by RIGHTCLICKING and then choose DOWNLOAD from the dropdownbox. Dont use leftclicking or open in WEB-app or EXCELL , goes wrong or to complicated.After download and eventual virus-check ( you never know with those duch foreigners) open it in Excell programm on your computer, but Open Office CALC can handle it too.

I espect a higher pressure for the same load then the D-load , so if you kept them to 65 psi the E-load need probably about 70 psi to be yust as save for the tires, and your old tires proved to have a save pressure.
Wear on the outside can also mean a uninteded camber angle or alighnment with tires pointed in or outside seen from above ( dont know the English word from above /-\ or \-/).


Here the links to the maps , but if you cant handle it , give the details ( here only of tires needed maximum load written from sidewall+ speedcode ), and I will do it for you and give a picture of the filled in spreadsheets.
To the motorhome calculator
https://skydrive.live.com/?cid=a526e...E092E6DC%21793

And to the traveltrailer calculator
https://skydrive.live.com/?cid=a526e...E092E6DC%21348
and a picture of the traveltrailer calculator to show the meaning

Here in the USA we have the Department of Transportation (DOT) as a governing body. They or their subservient branches write all the rules and regulations for highway safety. They reach out to other expert organizations for their guidance & input for establishing industry wide standards. Such organizations are the Tire & Rim Association (TRA) and Rubber Manufacturers Association (RMA) - just to name a couple.

Tire industry standards are nearly set in stone - so to speak. In many cases the only way to not follow their guidance is to "Do it yourself".

In the automotive industry there are numerous documents produced by the TRA identifying a suitable list of replacement tire selections including some plus sizing recommendations. The RV trailer industry has no such listings. In fact, replacement recommendations from the RV trailer manufacturers are few in number and often only provide one option.

However, there are industry standards for the procedure of upgrading and plus sizing RV trailer tires. The starting point is the trailer’s federal certification label. It’s sort of the vehicle manufacturer’s signature for the minimum standards displayed on it. It will have, among other things, the vehicle’s GVWR, GAWR, Recommended tire sizes and the recommended air pressure needed for those tires to support the loaded RV. Replacement tires must be of a size and load capacity to equal or be greater than the Original Equipment (OE) tires.

Under normal circumstances the vehicle manufacturer’s recommended tire pressure is the minimum acceptable pressure needed for safe operation with the OE tires. The replacement tires must provide equal or greater load capacity than the OE tires. Air pressure adjustments are allowed to attain that level of safety. But, they cannot be lower than the vehicle manufacturers recommendations. Once a new recommended tire pressure has been set for the replacement tire a notation should be made in the vehicle’s owner’s manual. Then an auxiliary tire placard, showing the new recommended tire pressures, should be affixed close to the original placard.

CW

[Festus2]

Let's not forget that the OP, Paul aka, Poppy's 5th Wheel has already bought and installed a set of Big Foots from Big O Tire and has stated that they "fit perfectly" and he is "very pleased" with them. While all of the above technical information may be useful to him, I am guessing that Poppy's 5th Wheel is quite happy with his tires, will ensure that they have the correct amount of pressure in them and perhaps is a believer in the KISS principle.

[CWtheMan]

Originally Posted by Festus2

Let's not forget that the OP, Paul aka, Poppy's 5th Wheel has already bought and installed a set of Big Foots from Big O Tire and has stated that they "fit perfectly" and he is "very pleased" with them. While all of the above technical information may be useful to him, I am guessing that Poppy's 5th Wheel is quit happy with his tires, will ensure that they have the correct amount of pressure in them and perhaps is a believer in the KISS principle.

Well, you let our friend from Holland post a lot of good information that maybe can be used in his country. So I just gave him a simple rundown on how the system works here. I also gave a little highlight on the procedure for setting the recommended tire pressures for plus sized tires. That’s what the OP has done, plus sized with LT tires. A recommended tire pressure of 73 psi will be needed in the OPs new tires to satisfy the vehicle manufacturer’s certified load capacity of 2540# per tire.

CW

On edit: I just finished writing a blog on this subject the other day. Maybe it will help others going to larger tires. here is the reference.

http://www.blogger.com/blogger.g?blo...0;src=postname

[jadatis]

Originally Posted by CWtheMan

Well, you let our friend from Holland post a lot of good information that maybe can be used in his country. So I just gave him a simple rundown on how the system works here. I also gave a little highlight on the procedure for setting the recommended tire pressures for plus sized tires. That’s what the OP has done, plus sized with LT tires. A recommended tire pressure of 73 psi will be needed in the OPs new tires to satisfy the vehicle manufacturer’s certified load capacity of 2540# per tire.

CW

On edit: I just finished writing a blog on this subject the other day. Maybe it will help others going to larger tires. here is the reference.

http://www.blogger.com/blogger.g?blo...0;src=postname

Cant open your blogg , have to singn in with my Ymail adress but then gives that I dont have access to your page or something.
But will give you a personal message, because i suspect that you know a lot about tires, and mayby I get wiser from you.
I am not working in the tire-business, but got hold of the formula of standards manual 2007 page 14 from ETRTO and went running with it.

But for this topic, how did you came to the 73 psi needed 2540 per tire?
Do you know the exact maximum load and needed pressure for that of this specific tire, tought it was not given for shure here, but can be wrong.

But laws of nature rule above laws and regulations of country's and organisations. They punnish with tire-failure and blowing tires if you dont keep to them.
And thoug the regulations are printed in stone, they are not holy.

I have got a lot wiser by an article of an American IR J.C.Daws, who presented an other way of calculating tire pressure ( mentiones the names Padua and Rhine) and compares it with the different formula's used in Europe and America with a power in the formula.
Here the link to his page with publications take the 7 doth at the moment.
http://www.dawsengineering.com/desite4_003.htm
TRA swiched over to the calculation of ETRTO ( European tire and rimm techinical organisation) in 2005 but only for standard load/P-tires and Extraload/XL/reinforced. In America for C-load/6Pr tires and up still a formula is used that leads to to much deflection in the lower pressure/loadcapacity range, wich can cource tire damage and blowouts. Euirope uses this formula for all kind of tires from SL/P-tire up to H-load/16pr since decades.
In my spreadsheet I use now my own universal formula, from wich the conventional European and American formula can be made by placing other power in it , but also that presented by mr Daws by placing , as I babtised it , a contruction load, and combinations of that. This makes it possible to compare.
So my spreadsheet can also be used in America, and then will give saver pressures because my formula takes care of same deflection over the whole range wich is the goal of all calculations. Also I add a reserve for things like weightdifference R/L, pressureloss in time , etc. So I give a high pressure advice that still gives acceptable comfort and gripp.


But enaugh for here , rest I will Personally mail you about.

[JRTJH]

When reading the OP's original question and his subsequent comments to this thread, he posted that the Sailun tires he originally purchased were too large to fit his wheel wells and he exchanged them for a set of Big O LT tires that fit well and have a cargo rating higher than his GVW. He posted the information on load rating (which may or may not be correct) from the Big O website.

It seems that his thread, about his tires, has been "modified" by additional posters into one that has become "Who can post the longest cut/paste technical response".

This thread is not about how to calculate tire pressure based on loading weights, it's about Poppy's Fifth Wheel Tires. Let's get back on track and stop the highly technical "off topic" posts.

[byrdr1]

Originally Posted by JRTJH

This thread is not about how to calculate tire pressure based on loading weights, it's about Poppy's Fifth Wheel Tires. Let's get back on track and stop the highly technical "off topic" posts.

I like the way his tires look on the new rims, I also like the way the Sailuns looked. I just put 2 maxxis 8008 on the back axle on my camper. When I get 300 plus extra dollars I will put them on the front axle and just maybe a spare. I had one tire bulging.
I think I paid around 312.00 this was mounted, balanced and threaded steel tire valve. I took the rim&tires off the camper and ran them by my tire guy. I run the recommended 80 PSI in them on every trip. I also used my torque wrench to replace them following the torque sequence from Keystoen for rims.

[CWtheMan]

Originally Posted by JRTJH

When reading the OP's original question and his subsequent comments to this thread, he posted that the Sailun tires he originally purchased were too large to fit his wheel wells and he exchanged them for a set of Big O LT tires that fit well and have a cargo rating higher than his GVW. He posted the information on load rating (which may or may not be correct) from the Big O website.

It seems that his thread, about his tires, has been "modified" by additional posters into one that has become "Who can post the longest cut/paste technical response".

This thread is not about how to calculate tire pressure based on loading weights, it's about Poppy's Fifth Wheel Tires. Let's get back on track and stop the highly technical "off topic" posts.

You know, low tire pressure/over loading, which are synonymous with each other, are the number one cause of RV trailer tire failures. Therefore knowing the correct tire pressure to use with replacement tires is very important.

The OP listed his new tires as being able to support 3042# of load capacity. However, he says his tires are of a size where the maximum amount of load capacity they can support is 2680#. So, if he uses the load inflation chart for the 3042# tires and sets them to provide the amount of load capacity provided by his OE tires (2540#) he would use 63 psi which would only provide about 2230# load capacity for his installed tires. Under inflated by 210# each.

It may still not be clear and that’s a large paragraph. He needs 73 psi in his new tires. If he says he knew that, than I apologize for wasting my time and your forum's space.

CW

[JRTJH]

CWtheman,

When your technical answer followed by a similar technical answer from another member followed by your technical answers to the technical answers with added technical considerations followed by technical responses followed by a technical discussion of technical techniques that the two technical discussers follow each other, it comes to a point where whether the knowledge you have is shared or not, few (if any) members will feel the need to follow your technicalities.

The fact remains that Poppy's 5th Wheel started a thread about his experiences with Sailun and Big O tires which was "pirated" by you and another member and turned into a thread generally consisting of who can impress the other best. Nowhere in his posts did Poppy's 5th Wheel ask for advice about tire loading/inflation guidelines. It's time to return the thread to the OP and if he asks for inflation guidelines, maybe a PM would be appropriate.

[SAD]

Originally Posted by JRTJH

...It seems that his thread, about his tires, has been "modified" by additional posters into one that has become "Who can post the longest cut/paste technical response"....

This right here was chuckle-worthy LOL