confusion on psi on TT

[Buly]

Here is the Michelin radial tire wear patterns chart. Over and under inflation pattern is still in play.

 

[BGMAC]

Well, I’m not sure about all that. Looks like they kept pics of the old bias ply’s. It could happen if excessive over pressure. I’m running 15 psi over. Been doing it for 40 years since I read the article with no uneven tire wear. I’m comfortable with that.

Id say follow the limits, you won’t go wrong. I’m just stating what I read and what I practiced and what my results were.

This has been a fun discussion. i enjoy stuff like this. @Buly Id like to meet you sometime around a fire. I think we could have a lot of fun bantering back and forth.

 

[Buly]

Well, I’m not sure about all that. Looks like they kept pics of the old bias ply’s. It could happen if excessive over pressure. I’m running 15 psi over. Been doing it for 40 years since I read the article with no uneven tire wear. I’m comfortable with that.

Id say follow the limits, you won’t go wrong. I’m just stating what I read and what I practiced and what my results were.

This has been a fun discussion. i enjoy stuff like this. @Buly Id like to meet you sometime around a fire. I think we could have a lot of fun bantering back and forth.

BGMAC, we can meet the end of Sept. We are going to the annual canards fly-in at Rough River KY ?

 

[Lunge motorsport]

Tire pressue on a TT, here’s my take…

I’ve pondered this a lot over the years and this is what I do. I inflate to max recommended pressure as stated on the sidewall. My rationale is this. For most RV’s the tires age out long before they wear out. If yours don’t then good for you, you are getting your monies worth. Mine age out so over inflation for wear considerations does not concern me. Ride quality with the stiffer sidewall is not a consideration for me either. Most TT’s have leaf spring axles which I consider to be junk suspension, softly sprung, and bumpy without quality dampening characteristics. I secure all of the stuff in my trailer and no one rides in there. I read a post on another forum where the guy was suggesting that he wants maximum contact patch with his trailer tire for best grip and performance. Really? If a trailer requires that consideration, I would suggest that it is being pulled way too fast. So, I run max and I hope to wear the center tread out at the same time they age out, doesn’t happen for me. A side benefit would be that the reduced rolling resistance may increase my fuel mileage, however little that might be on a 10k brick going down the road.

Now I’m no stranger to tire inflation pressure adjustment, in fact I encourage it in the tow vehicle and any street car. I set mine on all my vehicles using a pyrometer. I do this loaded and unloaded. This method will provide you accurate pressure settings by giving you accurate tire temps across the tread. My dually rides crazy stiff empty, unloaded and loaded the inside rears want 5 psi greater pressure than the outside rears. I would only know this by reading the temps after a long run down the highway. I have to be fast because the temps tend to average together if an immediate measurement is not taken. My rears empty run 35 psi inside and 30 psi outside, for example. I’m sure some of you out there will argue this, I’m okay with your opinion, change my mind…

Cheers

 

[Bob K4TAX]

We run LT radials on the truck tow vehicle and ST radials on the trailer. I'm informed that P-rated tires are for passenger car applications. Normally around town, I have 30 PSI in the truck tires for a bit more comfortable ride. When we tow, I bring the truck tires to 40 PSI. The Max Pressure on the side of the tire is 44 PSI for the rated load. The trailer always starts out at 55 PSI. I figure it will always be loaded to the max and likewise for the truck.

A very important point, we do not exceed the speed rating of the trailer tires. The load range D tires are rated at 60 MPG as I recall. We drive 60 MPH and let the "show outs" pass us by. I'll likely pass them as they change a tire on the side of the road. The 60 MPH and 70 MPH difference on a 300-mile run is less than 45 minutes. That speed number is there for a reason. The human stress factor is much less during a 60 MPH run as well as lessened fuel consumption.

My saying "if you intend to exceed the maximum speed rating, then you just became a very underpaid tire designer or tire test driver." We all are going to end up on the mortician's cooling slab at one time or another. I prefer to arrive later than sooner.

 

[BGMAC]

BGMAC, we can meet the end of Sept. We are going to the annual canards fly-in at Rough River KY ?

We will be in Ky 11-15th of Sept. for a military reunion. A group of us stationed in Germany try and meet every year at different places. This time near Barron River Lake. I’d like to see some of those aircraft.

 

[Buly]

The canard fly-in at Rough River airport 2I3, in the Falls of Rough River, Kentucky. - Canard Owners and Builders Association

www.canardowners.com

 

[John&Andrea]

Under inflated tires will have more resistance and heat up quicker, possibly leading to failure. Right?

 

[Buly]

John, you are right.

 

[Bob K4TAX]

Going over the numbers, our trailer's gross weight is 7685 lbs. With 4 tires under this trailer, this says the load is expected to be 1921 lbs per tire. The difference between the dry weight of 5715 lbs and the gross weight of 7685 is 1970 lbs. This is cargo weight, thus the allowable weight for any and everything added to the trailer. Such as battery, 2 x LP tanks, chairs, folding table, portable grill, leveling blocks, chocks, toolbox, and all the "stuff" we carry in the trailer.

The original tires were load C rated, thus a maximum 1600 lbs at 55 PSI. Clearly, the original tires WERE NOT rated to carry the maximum load of the trailer!

The new tires are load D rated. Per the manufactures data, they are rated for 2040 lbs at 65 PSI. That provides about 8160 lbs of total tire weight rating.

A point to note, changing to higher load-rated tires DOES NOT increase the maximum load rating of the trailer. That is defined by the axle rating used for the trailer. A pair of 4000 lb axles can safely carry 8000 lbs, regardless of the tire ratings.

Please check your trailer's gross weight rating and your tire's maximum load rating. Overloading tires are a sure formula for major issues. And as the tire manufacturer states for ST style trailer tires, always cold inflate to the maximum pressure to carry the maximum load.

Tire wear, surface contact, and ride are not as important as proper weight rating and inflation. If the tires are the correct size, weight rating, and inflation, none of the issues of tire wear, surface contact, or ride will be affected.

If you have had tire failure at any time, you best look at the numbers. Overloaded tires and under-inflated tires are the major cause of tire failure. Tires over 5 years old from the date of tire manufacturer are subject to dry rot and should be replaced regardless of appearance.

Remember, the strength of a chain is defined by its weakest link.