Tire pressures

[Oz-Kioti]

I'm trying to sort out proper tire pressures on my RX8030 (76hp), Front Wheel Assist.

I don't have access to scales to get definitive front/rear axle loads, so I've made an assumption of 40/60. Gotta start somewhere!
The tires are radials, and I normally leave the bucket on when slashing/mowing.

Does the following look right? It's based on the Firestone charts, and I just want to know if I'm reading them correctly:

 

[LouNY]

I'd do a bit different numbers;
tractor 6400 40/60 2560 / 3840
operator 200 0/100 200
FEL 1300 60/40 780 / 520
Bucket 550 110/ -10 605 / -55
Raised slasher 1250 -10/110 -125/ 1375
4020 / 5680

tires each front 2010
tires each rear 2840

Of course anything you put in the loader will increase the front weighting and decrease the rear weighting.
I would run the fronts at close to 20 normally and if heavy loader work is anticipated I would that them to their max pressure.
The rears if 9 feels good to you and you don't have a lot of sidehill work should be good, side hills at 9 could roll a tire bead off,
but if the tractor feels good go for it.
My numbers are just guesstimates from watching how different tractors have performed at different loads and conditions.

 

[Oz_Kioti]

Well, I've settled for the moment on 19psi fronts & 13psi rears.

That's based on having a 500kg load on the loader (bucket off, forks on, 500kg on pallet) in which case I would also use the slasher/mower/bush hog as rear ballast. With no load front or back, the pressures will be higher than ideal, but I don't feel inclined to faff with them every second task.

So I'll see how that feels next time I do some mowing. Last time I got bounced around a bit on some recently re-sown pasture.

By way of interest, the Kioti manual has this in relation to pressures, and that's using cross-ply tires as an example. There's no mention in the manual of the radials it came with:

 

[Anakist]

The RX8030's I have been pre-delivering lately are coming with Korean ag tyres that are rated 23PSI front and rear. Not sure if they are a special order for that customer or if that is what they are coming with.

James

 

[ROUSTABOUT]

20 front and 13 rear. Been running those pressures for decades on tractors that size.

 

[mo1]

If you have a loader mounted to the tractor, running the fronts at maximum pressure like the manual recommends is a good idea. You should be able to find information from the tire manufacturer regarding inflation pressures. Radials often have different values than bias ply tires, and tires with different ply ratings/load indices will also have different inflation pressure recommendations. You do not want to pick up anything heavy with underinflated front tires, and then pop the bead off of the rim when you turn. My loader is essentially nonremovable so I run my front tires at full pressure all of the time. I run my rears at the recommended pressure (18 PSI.)

I would only reduce pressures if the loader is off. Do note that at lower pressures, particularly below about 12 PSI, you will need to check your pressures often as most tires leak a tiny bit and this can lead to issues if your pressures get too low.

 

[oosik]

My tires are R-1 bias ply. But I also think that my procedure is sound for most all tire types.

I lift heavy loads with my grapple. My front tires are run at 35 psi. I still must be careful with very heavy loads. Don't want to run the tires off the rims. 35 psi is 5 psi above sidewall recommendations.

My rear tires are filled with Rim Guard. I run them at a pressure where I will get a full chevron contact patch on a hard surface. I motor out onto my driveway and check the contact patch. Last time I actually checked the pressure - right around 16 psi.

Been this way since I bought the tractor, new, in 2009.