Tire pressure: max pressure and actual pressure

[dvan1901]

Ok, I have a question about tire pressure. My tires are a "C" load range with a max pressure rating of 50psi. What pressure should I run the tires at? 50 psi, 45 psi? It's a tandem axle trailer and the tires are rated at 1750lbs at 50 psi.

 

[JRJ]

Re: Tire pressure: max pressure and actual pressure

Inflate to max pressure as stated on sidewall. ST trailer tires are typically rated to 65 MPH. Check with your tires manufacturer for additional info. Easy to do on line. Have fun.

 

[Rancherlee]

Re: Tire pressure: max pressure and actual pressure

The max tire pressure on the sidewall is Cold Pressure.

 

[tashasdaddy]

Re: Tire pressure: max pressure and actual pressure

this and worse is what happens to under inflated trailer tires. they over heat.

 

[mudweiser]

Re: Tire pressure: max pressure and actual pressure

Inflate to max pressure as stated on sidewall. ST trailer tires are typically rated to 65 MPH. Check with your tires manufacturer for additional info. Easy to do on line. Have fun.

If you don't mind, what is a St trailer? Not to hijack your post, but i'm running an Escort trailer single axle hauling a 89 Arriva 2050 with a 305 v-8. It's the stock trailer for the boat with tire size F78-14. "tires made in Tiwain". There is a MFG tag on the trailer but the print has worn off so it's not readable. There is no max pressure on the side of the tires... Odd. Any idea what pressure to run in those cheap offshore tires?

 

[Silvertip]

Re: Tire pressure: max pressure and actual pressure

ST stands for "Special Trailer". F78-14 is a passenger car tire and is not the best tire for a trailer. ST tires have stiffer sidewalls and most are rated at 50 PSI max pressure which is where they should run, loaded, half loaded, or empty. The tire killer with trailers is sidewall flex which results from under inflation. That builds heat causing cord separation, tread separation and/or blow out. Current auto tires are generally rated at 36PSI max but are designed for ride and handling with much different suspensions than found on trailers. I have a 3000# trailer with 10 inch wheels and tires but the tires are 10 ply and they carry 90 PSI. Every modern tire has maximum inflation pressure on the side. Trailer tires should always be inflated to that pressure and pressure needs to be checked often.

 

[mudweiser]

Re: Tire pressure: max pressure and actual pressure

Ahh, maybe thats why the trailer has a slight side-to-side rock to it when i first take off from a stop light. Looks like it's time to go tire shopping. Thanks.

 

[Silvertip]

Re: Tire pressure: max pressure and actual pressure

The side to side rock or waddle is due to the fact the tire(s) probably have suffered a partial belt separation. That makes the belt run off true center so the tire waddles as it rolls over the uneven belt. Ever ride in a car with the same problem. You can feel the back end of the car waddle at 10 - 20 mph but it tends to lessen at higher speed. If you were to follow the trailer you would likely be able to see the separation as the tread waddles as the wheel rotates.

 

[mudweiser]

Re: Tire pressure: max pressure and actual pressure

The side to side rock or waddle is due to the fact the tire(s) probably have suffered a partial belt separation. That makes the belt run off true center so the tire waddles as it rolls over the uneven belt. Ever ride in a car with the same problem. You can feel the back end of the car waddle at 10 - 20 mph but it tends to lessen at higher speed. If you were to follow the trailer you would likely be able to see the separation as the tread waddles as the wheel rotates.

Silvertip, you hit it right on the money......... Hmmmm. It all makes sense now. So for example, say a guy lost a wheel going down the freeway at 70MPH on the way home from just buying a boat. Maybe a wheel and tire happened to fall off due to loose lug nuts. Luckily rolling past their truck going 70MPH, down the center median towards trafic then back in your lane, missing the semi tractor/trailer then rolling to a rest and being brought back to you in a M.D.O.T truck who happened to be behind you and seen the whole thing. I seen this all through my windshield. Tires will pass you up! ya, no fun.... There is a cut all around the very nice tread of the tire about 1/4" deep. Had a local tire shop mount it and balance it on a new rim. Even after i told them what happened, now i realize they should have known this tire could very well fail and it should be replaced. Least no one was hurt, and i found why i get that side to side wobble. The boat was fine minus a slight scratch where the fender was pushed into it. Had to replace the brake backing plate, brake pads, brake drum, lugs and a rim. Not too bad with all involved considered. I just thought it was a cheap knock off tire causing my wobble. Guess it's time to go tire shopping.

To dvan1901: here's a good example of what can happen to lack of maintenance on your tires/wheels/trailer. Don't get me wrong, i'm not saying your rig is unsafe or your not tending to it by any means. Just please address it. The last thing i would have ever thought was to check the tightness of the lug nuts when buying a boat.