Tires: Treadwright

[dripley]

I might have to agree with you on more pressure. If nothing else it would seem to me to wear the centers out prematurely. The photo does appear to show them riding on the center 2/3 of the tread. I am curious as to what you ended up with cost wise. Tires, shipping, mounting and balancing.

[diesel4life]

Sorry I missed the part on running on the center. What is the max rated pressure of those? It sounds like you are experiencing the same thing a few of my friends with their TOYOS have experienced new. Iv'e also been in a few MDT's with new retreads and they felt very similar until they got scrubbed a little.

[Rogan]

I might have to agree with you on more pressure. If nothing else it would seem to me to wear the centers out prematurely. The photo does appear to show them riding on the center 2/3 of the tread. I am curious as to what you ended up with cost wise. Tires, shipping, mounting and balancing.

Tires shipped were 684 $ for 6. Mount, bal, and alignment was another $190.

Sorry I missed the part on running on the center. What is the max rated pressure of those? It sounds like you are experiencing the same thing a few of my friends with their TOYOS have experienced new. Iv'e also been in a few MDT's with new retreads and they felt very similar until they got scrubbed a little.

Supposed to be standard casing spec. Max 80psi. Im running what the door jamb says. Sent from my SPH-L710 using Tapatalk 2

[sngsht]

Apparently some dont put the dot on anymore as its apparently more the wheels fault these days. Who knows. I'm not a tire specialist lol.

Cooper still puts the dot on their domestically produced tires (at least at our plant) The tires come out of the presses,go thru inspection,then on to the balancer's that grind the white letters, and give them a finish grind if needed. Then mark they mark the heavy spot before kicking them down the line..The Chinese manufactured tires I've seen don't have that mark, and have a lot of runout and balance issues - we rework A LOT of our China made tires.

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So I towed my 20 ft enclosed at about 5000# gross yesterday. It was one word: squirrelly. Almost uncomfortable. Rears were about 75, fronts were 60-65. Ive since set fronts to 70 and rears to 65. It definitely seems to ride on the centers of the treads.

[ATTACH]5608[/ATTACH]

Now I dont know if thos it a tire issue, air pressure issue, or a front end issue that reared its head after the alignment.

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Two things come to mind here, I know airing up is the right thing to do when hauling ,but anytime there's daylight showing on the sides there's some sort of issue. The first obvious thing to me is the pressure is too high ( sidewall composition will affect this,so regardless of what pressure used on the last set,this set may be different) , in order to wear properly they must have the proper (full) contact patch. This may be why some have found they seem to drive better after the carcass wears in, it will absolutely affect handling and wear, probably causing it to run hotter as well? Perhaps the tread package has to much of a crown built into it to allow running the proper PSI, without running on the centers??

The other is ,have you tried rotating them? I've always went by the old school adage, that you never switch the rotational direction of a radial, I don't think it's a critical now as back in the day, but it never hurts. Perhaps the belts were "broke in" with a different rotation, and maybe rotating to a different side might help?

[Rogan]

So I just got off the phone with Treadwright, in discussion of the tire contact patch and air pressures.. They basically said:

Follow the vehicle manufacture's specification on tire pressures (located in the door jamb), not the tire casing. It is typical for the early stages of the tire's life cycle to ride on the center 2/3 portion of the tread, due to design. You'll notice that the tread-depth is quite deep, so this wear will even out. If you feel it is 'over-inflated', then you can use your judgement to drop the air pressures or not, but we recommend the vehicle specs.

[Mopar1973Man]

Just for fun... Here is the Hifly's I bought...My multi-tool is 9 inches wide to show tread width. Currently inflated a bit over because of firewood hauling but...After I'm done hauling firewood this what I'll inflate too.Front axle Tire Pressure4440 / 2 = 2220 / 3042 = 0.72 x 80 = 58.3 PSI (60 PSI)Rear Axle Tire Pressure2860 / 2 = 1430 / 3042 = 0.47 x 80 = 37.6 PSI (40 PSI)

[Rogan]

So how about math for my dually? LolSent from my SPH-L710 using Tapatalk 2

[Mopar1973Man]

So how about math for my dually? Lol

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Same math. Just use the dual weight instead of single weight. You'll notice dual weight is typically lower and so the pressure should slightly higher.

(axle Weight / 2) / Dual Tire Weight Limit x Dual inflation Max Pressure = Inflation pressure.

[diesel4life]

What manufacture/size tires are those Mike?

[bjytech]

Same math. Just use the dual weight instead of single weight. You'll notice dual weight is typically lower and so the pressure should slightly higher.

(axle Weight / 2) / Dual Tire Weight Limit x Dual inflation Max Pressure = Inflation pressure.

Its been a bit of a lazy morning for me so I saw this and decided to make a little program up just for fun to do the calculations going by your formula. http://db.tt/FN8qKVC4

[Mopar1973Man]

Now just compile a version for us Linux people now too. I really don't want to have to boot up Windows.

[Mopar1973Man]

What manufacture/size tires are those Mike?

Here is the dealer web page... http://www.bigotires.com/Tire-Detail/HIFLY/VIGOROUS-AT-601/23448 I got the 235/85 R16's...

[Rogan]

After I'm done hauling firewood this what I'll inflate too. Front axle Tire Pressure 4440 / 2 = 2220 / 3042 = 0.72 x 80 = 58.3 PSI (60 PSI) Rear Axle Tire Pressure 2860 / 2 = 1430 / 3042 = 0.47 x 80 = 37.6 PSI (40 PSI)

So if my axles are: Fr: 4850 Rr: 7500 Tire: 3642 @ 80psi Fr: 4850 / 2=2425 / 3642 = .67 x 80 = 53.3 (55psi) Rr: 7500 / 4=1850 / 3642 = .51 x 80 = 41.2 (40-45psi) IS that right? That's using the door sticker's axle weight and BFG tire numbers.

[bjytech]

Now just compile a version for us Linux people now too. I really don't want to have to boot up Windows.

Heres the python file that should run in ubuntu. all you should have to do is click it and run in terminal. http://db.tt/TKWKowif edit1: Just realized a flaw in my program, its only accounting for 2 tires across a axle at the moment. edit2: Just updated the files to do both single rear wheel and dual rear wheel vehicles.

[Rogan]

I wasnt gonna say anything ;)

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Please Select an option to get started1. Single rear wheel vehicles2. Dual rear wheel vehiclesplease enter the number of your selection and press ENTER:2Please enter the weight of the front axle (.lbs) and press ENTER: 4850Please enter the weight of the rear axle (.lbs) and press ENTER: 7500Please enter the tire max weight limit (.lbs) and press ENTER: 3642Please enter the max inflation pressure (psi) and press ENTER: 80Suggested tire pressure for the front axle is: 53.3Suggested tire pressure for the rear axle is: 41.2

Nice app, dude!

[Mopar1973Man]

So if my axles are: Fr: 4850 Rr: 7500 Tire: 3642 @ 80psi Fr: 4850 / 2=2425 / 3642 = .67 x 80 = 53.3 (55psi) Rr: 7500 / 4=1850 / 3642 = .51 x 80 = 41.2 (40-45psi) IS that right? That's using the door sticker's axle weight and BFG tire numbers.

No. You got some errors. There should be a different weight rating on the tire for DUAL's vs. SINGLE's. They are never the same typically DUAL's are rated lower in weight. Second off you don't use door sticker numbers you use actual scaled axle weights. Like I know you rear axle right now is not weighing 7,500 pounds with a empty bed. Heck my entire truck doesn't weight much more than 7,300 pounds empty. (4440 + 2860 = 7300) My current axle weights front (4,440#) and rear (2,860#). My 235/85 R16 HiFly's rated for... 3042 SINGLE's @ 80 PSI 2778 DUAL's @ 80 PSI So using my actual scale weights and tire specs... FRONT: 4440/2 = 2220/3042 =0.72 x 80 = 58.3 REAR Single: 2860/2 =1430/3042 = 0.47 x 80 = 37.6 Here is where I get hung up. I need actually scale weights and then figure them both by 2 or by 4 and see what pans out correct also calculate maximum axle weight vs. normal Load Range E's. REAR Dual: 2860/4 = 715/2778 = 0.25 x 80 = 20.5 ??? (Awful low) REAR Dual: 2860/2 = 1430/2778 =0.51 x 80 = 41.1 Remember the door jamb is the MAXIMUM axle weight designed for the truck. REAR Max: 7500 / 2 = 3500 pounds This would create a figure above 100% (1.25 x 80 = 100.7 PSI ???) REAR Max: 7500 / 4 = 1875 pounds. This would fit but seem awfully low in pressure even at max load. (0.67 x 80 = 53.9 PSI ???) Seriously... I think is divide by 2 on both numbers but you got to use actual scale weight not the door tag.

[bjytech]

The math checks out for doing dually's by dividing by 4. The reason it seems to come up with such low numbers is because the tire's weight carrying capacity across the axle is greater than what the truck is rated for. For example with BFG T/A KO's in 245/75/R16 the ratings are 3042lbs@80psi single, 2778lbs@80psi dual.so in the dual application across the axle the tires are rated to handle a max weight of 11,112lbs but the truck axle rating is only at 7500lbs.Still though I wouldn't feel comfortable running 20psi in the tires.Also I updated my program to get both the single and dual weight ratings for the tires in the dual wheel mode.

[Mopar1973Man]

The math checks out for doing dually's by dividing by 4. The reason it seems to come up with such low numbers is because the tire's weight carrying capacity across the axle is greater than what the truck is rated for. For example with BFG T/A KO's in 245/75/R16 the ratings are 3042lbs@80psi single, 2778lbs@80psi dual. so in the dual application across the axle the tires are rated to handle a max weight of 11,112lbs but the truck axle rating is only at 7500lbs. Still though I wouldn't feel comfortable running 20psi in the tires. Also I updated my program to get both the single and dual weight ratings for the tires in the dual wheel mode.

Might have to change up the formula a bit to get a good pressure for the rear axle. Kind of like: Axle weight / Rear Axle Weight Limit x Tire Inflation Max Press. = Inflation Pressure 3500 / 7500 = 0.46 x 80 = 37.3 PSI 2860 / 7500 = 0.38 x 80 = 30.5 PSI So changing to that formula your basing tire pressure on a percentage of axle load. Increases the empty weight numbers.

[Rogan]

2778 @ 80psi dualIll see if I can scale the truck this afternoon. Sent from my SPH-L710 using Tapatalk 2

[Rogan]

Scaled it this afternoon.. 1/8 tank fuel, bed emptyFr: 4140Rr: 2840Truck: 7220Hows the ends not add up to the total? 6980 doesn't equal 7220..Sent from my SPH-L710 using Tapatalk 2