Tire inflation phenomenon - need input

[Bruce]

The plates does not have hp but it shows 15 amp @ 110vac which is 1 hp.

1 horsepower is 746 watts. 15 amps at 110 volts is 1,650 watts so the motor is around 2.2 hp. Most compressor manufacturers would rate it at 3 hp or more for marketing.

Please let us know how those tires hold up. I worry that they may explode at such high pressure.

 

[drewkaree]

Is there a picture of the sidewall showing the pressure, I know it was asked earlier in this thread? I asked, because along with many others in this thread, 90 PSI seems ridiculously high. The tires on my semi tractor and trailer require 100 PSI, so a boat trailer seems like, to me, it would be hopping all over the road at any little pebble LOL

 

[Joatmon]

Is there a picture of the sidewall showing the pressure, I know it was asked earlier in this thread? I asked, because along with many others in this thread, 90 PSI seems ridiculously high. The tires on my semi tractor and trailer require 100 PSI, so a boat trailer seems like, to me, it would be hopping all over the road at any little pebble LOL

Yes. The picture is near the beginning of the thread.

 

[Bruce]

Chinese 6 ply tires with suggested and max inflation of 90 PSI sounds like a recipe for using the jack to me but that really is what the manufacturer says.

Trailer Tire 4.80x12 Bias Ply 12 in Load Range C 990lb by Loadstar

 

[swatski]

Chinese 6 ply tires with suggested and max inflation of 90 PSI sounds like a recipe for using the jack to me but that really is what the manufacturer says.

Trailer Tire 4.80x12 Bias Ply 12 in Load Range C 990lb by Loadstar

Good info, @Bruce, very interesting.
If I had those tires I would definitely be inflating those to 90psi, if I could find a way. The tires look really narrow - I think that may be the key.
Narrow tires will generally need higher pressure, the super narrow road bike tires take anywhere between 80 and 130psi! (I know for a fact less pressure there leads to flat tires)

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[Joatmon]

What is even more concerning is the tires are marked 2 ply and not 12 ply. Maybe there was a confusion in the translation and they really are 12 ply.

I am now thinking about a tire upgrade. Being at 90psi they will more susceptible to pressure drop sooner than lower pressure tires.

 

[Bruce]

@Joatmon, the Loadstar info says they are 6 ply.

 

[haknslash]

What are these tires being used for?

 

[Joatmon]

What are these tires being used for?

I have a new small fishing boat and consulting members regarding the tires. The skiff loaded weighs 1800 pounds. My 25’ Scarab is too cumbersome to use for fishing in the bay by myself.

 

[Bruce]

The skiff loaded weighs 1800 pounds.

Those tires have a 990 pound capacity. Do you have two or four of them on the trailer? If a single axle with two tires including trailer weight the tires must be overloaded.

 

[Joatmon]

Those tires have a 990 pound capacity. Do you have two or four of them on the trailer? If a single axle with two tires including trailer weight the tires must be overloaded.

Sorry, I was including the trailer weight. Single axle.

 

[Andy NJ]

The terms tire load ranges and tire ply ratings tossed around together — one, which is designated by letters, and one, which is designated by numbers. They are actually terms from radically different historical eras that mean basically the same thing. Load ranges and ply ratings are both used to identify load and inflation limits for any given tire.
The historical term ply rating goes back to the days when bias ply tires were actually constructed of layer upon layer of cotton fabric — yes, cotton. Ply rating referred to how many layers, or plies, of cotton had been used in the tire’s construction, and the number of plies determined the strength of the tire.
In today’s modern world, tire plies are no longer made out of cotton. Now, tires are constructed using fewer, yet much stronger, plies so the term ply rating doesn’t refer to the actual number of plies anymore. Instead, the ply rating indicates an equivalent strength compared to early cotton-constructed bias ply tires.
If you see ply rating and load range on a chart, they both represent the tire’s maximum load carrying capacity at maximum allowable air pressure.
It’s the air that carries the load, the tire is just a well designed container for that air. 90 psi is normal inflation for that size load range c tire.
There are 4.80x12 load range B (4 ply) that have a max inflation of 60 psi, max load carrying is 660#.
Trailer tire failures are caused by underinflation (heat build up destroys tire), aged dry rotted tires, and then road debris.
Glad you got it figured out.