Tire and rim ratings

[frankie g]

Well, I'm researching tires for my trailer and I found tires 205 75 14's D rated 2250 lbs. @ 65 psi, that's great. I'm now running C rated 1760 lbs or so @ 50 psi. Now, I've been looking at Aluminium wheels as well, and noticed that they have ratings too! some are 1600lbs and some go to 1900 lbs, ***! my Galvanized rims are probably rated @ the lower of the 2. So if I put tires rated @ 2250 lbs @ 65 psi on those 1600lbs rims is there a hazards awaiting me? I thought I'd go with a higher rated tire for better wait distribution. My rig is approx. 5800 lbs loaded. I really don't want to buy 6 new tires and wheels in the 15" size, when I could buy 6 tires and just 2 new or used galvanized rims ( 2 spares ) Any thoughts on this?

 

[Silvertip]

Re: Tire and rim ratings

Ever heard the term "a chain is only as strong as the weakest link!" There is truth to that -- it is called "physics". The ability of a trailer to tote its maximum rated load depends on not just the capacity of the tires, but the wheels, axle, springs, and the frame. Upgrading one does not necessarily upgrade the total capacity. And your statement about "better weight distribution" is flawed in that weight distribution will still be the same. Whatever weight you had before the tire/wheel switch will still be the same with new wheels/tires. Upgrading tires and wheels is not an issue so long as you don't intend to exceed the loading of the rest of the system (axles, and springs). Conversely, downgrading any component does create an issue in that the "weakest link" enters the picture and may therefore lower your load capacity. People tend to underestimate the weight of their boats and trailers. If your rig fully loaded with fuel, engine, gear, batteries, coolers, etc. is indeed 5800 then four 1750# tires provides 7000# load capacity. If the 5800 does not include the weight of the trailer you would be very near the 7000# limit whereas there would be plenty of buffer if the all up weight was 5800.

 

[frankie g]

Re: Tire and rim ratings

5800 is boat motor trailer and stuff. many tire failure is due to near max. weight. I thought by going w/a higher rated tire I would have a better chance of NOT haveing the failure. Haveing D rated tires on this rig is not better that C rated tires??????? I'm hopeing for a little better edge! Its hot in Fl and if I can put a better more beefier tire on then why not! but is there danger in putting 65 psi in a rim that rated for 50 psi? Whats the story w/ the rims? do you have any thought s on that? I never heard of those ratings and now that I'm looking into it....I'm seeing that there are. What about the higher rated tires what rims are they using?

 

[dingbat]

Re: Tire and rim ratings

many tire failure is due to near max. weight. I thought by going w/a higher rated tire I would have a better chance of NOT haveing the failure. Haveing D rated tires on this rig is not better that C rated tires??????? I'm hopeing for a little better edge! Whats the story w/ the rims? do you have any thought s on that? I never heard of those ratings and now that I'm looking into it....I'm seeing that there are. What about the higher rated tires what rims are they using?

Have you weighed your rig? It makes absolutely no sense to "upgrade" your equipment blindly.

 

[frankie g]

Re: Tire and rim ratings

Why not! I haven't run into any problems w/ my exsisting tires. Its time for tires so I thought I'd go w/ a higher rated tire for the extra protection! why buy C when I could buy D rated. The extra cost is minimum so why not! but when I started the look into it I was surprised of what I was seeing. I just don't want to get the D's put them on, have 2 spares of the same and find out I'm in worse shape than when I started.

 

[allinmygarage]

Re: Tire and rim ratings

My 02 Cents only because I just purchased new tires. Discount Tire told me the #1 cause of tire failure is overheating due to under inflation. I think the weakest point in all trailer systems is the bearings. So upgrading your tires will do nothing to impact the load on the bearings. If your towing 5800lbs and the 4 tires together are 7000lbs then you are nowhere near max. Personally I would not upgrade. Also remember if you go with a larger rim or tire you are losing breaking.

Now if you are going for a better looking rim and tire to match the truck then do it

 

[frankie g]

Re: Tire and rim ratings

No, same load, same size Gal. rims, same size tire....just wanted to get D rated tires over C's. Not trying to save my bearings or springs or anything else. Just wanted to know if I'm causing a problem

 

[allinmygarage]

Re: Tire and rim ratings

You?re not causing a problem at all as far as I know. Some of us just like to save the extra bucks for more gas and beer

 

[dingbat]

Re: Tire and rim ratings

Why not! I haven't run into any problems w/ my exsisting tires. Its time for tires so I thought I'd go w/ a higher rated tire for the extra protection! why buy C when I could buy D rated. The extra cost is minimum so why not! but when I started the look into it I was surprised of what I was seeing. I just don't want to get the D's put them on, have 2 spares of the same and find out I'm in worse shape than when I started.

Probably the Engineer showing through but I've alway lived by the motto, If it ain't broke, don't fix it.

 

[QC]

Re: Tire and rim ratings

Moved this to the trailer section . . . Good discussion

 

[bruceb58]

Re: Tire and rim ratings

I have never seed D rated 14" tires. Which brand did you find that had these?

 

[frankie g]

Re: Tire and rim ratings

Kumho 851 trailer tires...a few good reviews too.... tire rack

 

[frankie g]

Re: Tire and rim ratings

Moved this to the trailer section . . . Good discussion

Oh! yea! good idea! thanks

 

[bruceb58]

Re: Tire and rim ratings

There is only one drawback to going up too high in load rating. With the higher load rating you will have less flex in the sidewall and the ride will be a little more jarring on the boat.

 

[frankie g]

Re: Tire and rim ratings

A manufacturer of one of the wheels contacted me and said the ratings on the rims are way under rated and it should have NO problem handling that type of tire rating or psi amount. The problem will be in the valve though. He recommends a high pressure valve w/stainless steel nut behind the valve, and it will be fine. So I guess that solves that. So if you want to be an extremist like me, go ahead it's ok. Hec why not!

 

[The_Kid]

Re: Tire and rim ratings

A manufacturer of one of the wheels contacted me and said the ratings on the rims are way under rated and it should have NO problem handling that type of tire rating or psi amount. The problem will be in the valve though. He recommends a high pressure valve w/stainless steel nut behind the valve, and it will be fine. So I guess that solves that. So if you want to be an extremist like me, go ahead it's ok. Hec why not!

Standard valve stems shouldn't be a problem since they are rated up to 65 lbs.

 

[frankie g]

Re: Tire and rim ratings

Lets look at it this way...If your trailer is rated 5000 lbs, would you load it w/ 5000 lbs? So why would you max. out your stems? The tires I'm looking at are D rated, @65 psi, I'll go by what the man. says...safety first. only a couple of bucks more for the heavey duty's. I use them on my SUV tires that are rated 65 psi, there's a big diff. in stems. the standards are pretty flimsy compaired to the high pressure, and why sacrifice a few dollars more when you have $$,$$$.$$ sitting on that trailer, on those tires. A few extra dollars for piece of mind... and a brake down, w/ a flat on the interstate! na I'll go high pressure. I know you all must think I'm crazy but maybe I am!!!

 

[bruceb58]

Re: Tire and rim ratings

I don't. I think its an excellent idea. I basically did the same thing when I upgraded to 15" tires in order to get the load rating up. I also wanted a little more clearance..I have a steep driveway.

 

[Silvertip]

Re: Tire and rim ratings

You obviously did not understand my comment. IF the trailer is currently NOT overloaded for the springs and axles, then going to a larger tire or one with a higher load rating is not an issue. BUT -- IF you add bigger tires or tires with a higher load capacity AND you increase the load, you may now create a problem because you overloaded the springs and/or axles.

 

[frankie g]

Re: Tire and rim ratings

No, I never said it was over loaded! I was asking if there would be any negitve results by putting on D rated tires on rims that weren't rated for that much psi, Cause I never new that the rims as well were rated, but now I know, from the man. it would be all right to do so with no negitve results. We just weren't on the same page...thats all. Thanks