Inflation change for loaded tires?

[Mossy dell]

Hi, am just getting down to basics with my new B2601. When I took delivery, I asked about tire pressure and the salesman said “20 psi all around.”

This is close to what the owner's manual recommends on the front for my R14 hybrid tires: 22 psi for 23 X 8.50-12 R14T GOODYEAR SST

Not even close on the rear: 40 psi for 12-16.5 R14T GOODYEAR SST — but the rears are filled.

So is it a rule of thumb to reduce the recommended air pressure by about 50 percent for filled tires? I can't even remember what I did on my tractor 10 years ago but recall it being pretty low pressure in the filled rears.

 

[foobert]

Pressure should be the same, even when liquid filled. But, 40 PSI for a rear sounds way too high. The rule-of-thumb in every tractor manual I've read from Deere to Kubota shows a picture of a "detectable" outward bulge at the contact patch illustrating proper pressure for your operating weight, followed by the improper illustrations of a squared off contact patch and excessive rounding.

As a for instance, I run my BX rears at 15 PSI -- much better ride and less wheel spin under load compared to the 22PSI it was delivered with.

 

[85Hokie]

With air still left in the tire once filled - pressure IS pressure. There should be no lessening of PSI vs non loaded tires.

However - there is less "shock" absorption since the liquid is taking up some of the air ability to move in all directions.

TO much air lead to a bad ride - remember the air in the tire is the ONLY shock you have - too much and the ride is very stiff and hard on the body - from back to teeth!!!

Like Foo said - the PSI is lower for grip and ride comfort, however - low on the front when using the FEL is a bad thing!

 

[Mossy dell]

Pressure should be the same, even when liquid filled. But, 40 PSI for a rear sounds way too high. The rule-of-thumb in every tractor manual I've read from Deere to Kubota shows a picture of a "detectable" outward bulge at the contact patch illustrating proper pressure for your operating weight, followed by the improper illustrations of a squared off contact patch and excessive rounding.

As a for instance, I run my BX rears at 15 PSI -- much better ride and less wheel spin under load compared to the 22PSI it was delivered with.

Thanks, but tell that to my owner's manual. It may "sound" too high, does to me too, but that's what it says.

 

[Mossy dell]

With air still left in the tire once filled - pressure IS pressure. There should be no lessening of PSI vs non loaded tires.

However - there is less "shock" absorption since the liquid is taking up some of the air ability to move in all directions.

TO much air lead to a bad ride - remember the air in the tire is the ONLY shock you have - too much and the ride is very stiff and hard on the body - from back to teeth!!!

Like Foo said - the PSI is lower for grip and ride comfort, however - low on the front when using the FEL is a bad thing!

Maybe this is why salesman said to run 20 psi all around? I think I should follow the manual and go 22 for the front though because, as you say, the loader . . .

 

[Mlarv]

I would look at the sidewall of the tire and see what it says. Then judge from that which way to inflate.

 

[85Hokie]

I would look at the sidewall of the tire and see what it says. Then judge from that which way to inflate.

Sidewall pressures typically give MAX inflation numbers ........ which are fine - but depending on what end we are talking about and what we are doing - determines how firm or soft those tires should be pressurized

 

[Mlarv]

Sidewall pressures typically give MAX inflation numbers ........ which are fine - but depending on what end we are talking about and what we are doing - determines how firm or soft those tires should be pressurized

Yup that is why I said work from there. I run my truck tires lower then sidewall when I am not hauling anything. If I am pulling a trailer or hauling then I air them up.

A tractor tire is a bit different where it wants more contact with the ground to help with ride and not tearing up a yard. If the sidewall says 40 I would most likely start at 20 and see how it goes for you. As long as they are not dragging the side of the rim into the rubber you should be good, also watch for turning that the rubber stays grounded and the rim doesn't pop the bead.

 

[mcfarmall]

I run 30 in the front and 10 in the rear with rears loaded at 75% with Rim Guard. My rule is the bars on my R1's make contact with pavement from one end to the other when the pressure is right. When the pressure is higher, only the bars make contact closer to the center of the tread.

 

[GreensvilleJay]

If you have a loader up front, or an implement out back, you best put the MAX (or close to it) PSI in the tires.You NEED that PSi to support the weight !

 

[foobert]

If you have a loader up front, or an implement out back, you best put the MAX (or close to it) PSI in the tires.You NEED that PSi to support the weight !

This is only true if you are ALSO operating at MAX load rating of the tire, which I doubt you'll find on most tractor tires (it's not listed on the sidewall of my R4's). For the skinny front tires running a loader, I think it's sound advice.

However, the load capability of the wider/taller rear tires does not universally dictate running at MAX PSI just because there's an implement on the back.

Going back to OP's rear tires -- they have a load index rating of 116 according to this, which translates into 2756# per tire at max of 40 PSI. A 1600# B2601 is going to have to struggle mighty good to gain more than 3x its base weight to justify running the rears at full PSI.

 

[GreensvilleJay]

I know the junk indian tires on my BX23S are rated for 770#(on the sidewall,thought it was law it had to be....) I use the loader a LOT,usually maxxed out and on 2nd set of tires.
don't know what else is on the machine..'base weight' doesn't include mower, loader,fuel or the driver...

 

[kubotafreak]

If you feel so inclined to not run max advertised pressures you might try this. Sometimes brush hogging can get bouncy with high pressure. Good rule of thumb is to inflate the loaded tractor as used so you have about 3 lugs touching the ground. This gives a good contact patch for traction. This mainly applies to the back since the front on the machine should stay close to max for loader use. If you run max on the rears with a load, you will find only one set of lugs touching the ground.

Bottom lug should be at 6:00 for this adjustment.

 

[Tx Jim]

I've been around/driving agriculture related tractors for over 65 yrs & I've never heard of rear tractor tires being operated at much over 20 psi certainly not 40 psi. Part/operators manuals have been known to contain some incorrect information!

 

[Mossy dell]

I could not see the max pressure figures on the sidewalls of these tires. The figures may be there but are awfully small if they are!

 

[GreensvilleJay]

maybe on the back side of the tire ???
normally it's something like ' xxxx pounds load @ yyy PSI'

 

[Mossy dell]

Right, it's probably there. I am pretty sure the max inflation exceeds what I'd use though. My experience with my Kubota dealership is very mixed, but it appears the salesman gave me pretty good advice on inflation! Now I have to check it . . .

The tires seem VERY inflated so i do need to put a gauge on them. I discovered doing my first greasing of the loader last night that two places had never been greased in the dealer's setup work. They are the two joints where the loader must be raised to get at them, at the front of the rear cylinder. I should have checked but could see grease everywhere else. However, a coupler on one side that's also harder to get to had been left loose and leaked .5 gallons of hydraulic fluid onto my garage floor by the time I noticed it the day after delivery. It took 1.5 gallons to replenish hydraulic fluid, so the tractor had been leaking each time it was moved on the dealer's lot or trailer.

 

[D2Cat]

If you have an area of flat concrete or asphalt you can take a piece of chalk and mark a line across the width of the tire tread. Drive around a bit on the hard surface then see where the line does not get wore off. That will indicate over/under inflation. Adjust pressure to get the best result of all the chalk line being wore off.

 

[B2710]

For my LX3310 R14s (loaded) the OM states 32 PSI which causes the tire to look like a overfilled donut with only the very center touching the ground and are bouncy to a level of almost dangerous.

I have been lowering pressures each week I mow, I am now at 15 psi and that seems ok from a contact patch standpoint and feels a lot better for ride but now they feel too soft when moving slopes sideways as I can feel the sidewall moving as the weight shifts around.

I am looking to purchase rims and R4 similar to what I had on my last tractor used for mowing.

YMMV....

 

[skeets]

The R 4s are skid loader tires and yes 40 PSI way to bloody hard for my money,, and yes with a filled tire the air space not filled should be the required air pressure, lest you risk rolling the tire off the rim, this is what was explained to me,, take it for what every you think it is worth