PT1850 Tire Pressure - 10 Ply Tires

[BWSwamper]

My recently acquired PT1850 came with 10-ply 26x12-12 trencher type tires. These are Samson brand, which a tire website suggests have a max inflation of 65 psi.

I'm trying to decide what pressure to run. When I took delivery, the tire pressures ranged from 2 psi to 18 psi.

I am thinking maybe 7 psi all the way around. I looked over the earlier posts, but couldn't find anyone else with 10-ply tires. I know I'm not going to get the slope performance of the softer tires at any pressure, but I'd like to run as low a pressure as sensible on these stiff tires.

 

[radios1]

putting in enough air to make the tires run flat(square) on the pavement contact is enough. just like on a car, except in this case, the air pressure should be adjusted for a full load, you don't want too much, nor too little. and the pressure will vary with temperature, too..

 

[MossRoad]

My recently acquired PT1850 came with 10-ply 26x12-12 trencher type tires. These are Samson brand, which a tire website suggests have a max inflation of 65 psi.

I'm trying to decide what pressure to run. When I took delivery, the tire pressures ranged from 2 psi to 18 psi.

I am thinking maybe 7 psi all the way around. I looked over the earlier posts, but couldn't find anyone else with 10-ply tires. I know I'm not going to get the slope performance of the softer tires at any pressure, but I'd like to run as low a pressure as sensible on these stiff tires.

Can't help you there. I've got turfs on my little PT425 and run at 10 and that's a bit too firm.

 

[woodlandfarms]

I had 12ply on my machine. Like they said, depends on load and use. You probably will never know if they are flat with an 8 wheel machine. I ran one tire for years flat, never knew it. I would put in 15 and see how it feels you can only lift 1200lbs with the PT so...

These tires are no bueno for steep slopes. Just bear that in mind if you want to go beyond 30 sideways.

 

[BWSwamper]

The stiffness of these tires is a problem for the "inflate until flat (square)" approach. They have a super thick sidewall and don't show much change in profile over a wide range of pressures. The one I found at less than 2 psi looked perfectly fine. I can sure believe that you ran a 12-ply flat without noticing.

I'll experiment and report back.

If the tires were a bit more worn, I'd just switch them out, but they all have a good bit of tread left.

Also, a general update:

I got the cooling fan issue sorted out. It was just a bad fan solenoid. The thermal relay was fine.
Also, the motor impeller shroud (Geblase Mantel) was cracked in half by a backup accident in the hands of the PO. I replaced the shroud.
While replacing shroud, noticed that the tensioner pulley mount was bent, apparently in the same accident. Straightened that out and reinstalled.
Had the cracked mower pump stand rewelded and then installed new mower blades.
Now the machine seems to stabilize a little below the upper middle tick mark on the temp gauge.

Also had a friend help me rebuild the FEL cylinders so the leak down is now very slow as in the descriptions given in posts here. Still need to rebuild one of the steering cylinders.

Thanks to everyone for all of the excellent advice during my initial PT-conversion.

 

[ponytug]

FWIW: Even on my 8 ply tires, I have had them down to zero psi without noticing. (Until doing a tight circle on a slope...)

I now run them about 15psi. It is a WAG of a number.

All the best,

Peter

 

[AVIVIII]

The previous owner of my 1850 was adamant that the front tires needed to be at 6psi and the rears at 5psi. Its even placarded on the dash. Seems to work fine with the 4 Ply Carlisle Tru Power 26x12-12 that it came with.

 

[woodlandfarms]

So psi is part is very important in slope mowing especially with soft grippy tires. I run my psi at 6 to 8 with somewhat stiffer 6 ply. You running less than 15 psi with super stiff 10ply might create odd wear. Dropping you psi to slope mower gripping levels will not gain you anything. Your tires are way too stiff.

 

[woodlandfarms]

Ohh Avi I. If you have 4 ply then 4 to 6 psi is correct. You need 4 psi and no more if you plan 45 degree slopes

 

[MossRoad]

I'd still like to get on one of those things and attempt 30-35-40-45 and see if I could stomach that. I get itchy at 20-25 on my little 425.