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.

 

[ernemats]

I have not gone past 30 degrees with my 1845 and I don't think I would go past that.

 

[woodlandfarms]

Trust me. Past 35 and I freak. I have hit 45 a few times but always had an out. It is freaky being on something so steep.

 

[MossRoad]

I don't think I have any place on my property that I'd want to go that is over 30. The only 30+ to 45 areas are the cut by the old railroad grade, and there's absolutely no reason to go there, ever. Heck, I can hardly walk up that while holding small trees for balance.

 

[cqaigy2]

Man, i know on my little pt, i've braced myself on the inside of top of the rops, but wow 45 is steep.

 

[MossRoad]

Yeah it is. Let's say you're 5'8" tall. Stand with your toes and nose against a wall and note on the wall where the top of your head is. Take two giant steps backwards. From the tip of your toes to the spot on the wall is about 45 degrees. Try imagining driving ACROSS that angle.... YIKES!!!

 

[4570Man]

This is 48 degrees. I’d like to see someone drive access a hill that steep.

 

[woodlandfarms]

So I was at a bit over 40. I stopped. I looked down the hill, If I had stepped off the tractor on that side I would have tumbled. It was a big drop from the level seat to the ground at that angle. Going up hill was the only choice and it was a scramble, hands and knees for traction.

I don't get how guys do this without having an out at the bottom (guys who mow dams on the water side). I have never been that steep without a clear cut way to get out not if, but when, you slide down the hill. It is truly scary, even with a leveling seat, to be that steep. My puckerometer really has issues beyond 30 even though I know it is completely safe, get beyond 40 and I am clutching the ROPs and freaking the heck out

4570. I am sure the PT 1850 can go beyond 45 without flipping. The problem is there is not traction beyond 45. There is barely any at 40. I ponder putting on those steel wheels with big spikes, the ones on that custom walk behind/ ride behind sold in germany. That would be some serious stiction.

 

[AVIVIII]

The previous owner showing it off before I demoed it. Where the tractor sits in the pic is ~25*. The bottom of the slope, towards the road, "below" the red car, is 30*. It is tense, but not uncomfortable. The pink line is 45* and seems completely unfathomable to me...

I've taken the 1850 to 30+ a fair amount and after putting a permanent crease in the seat of the JD on some of my hill, the PT is very comfortable! The loss of traction becomes very apparent at and above 30, especially mowing brush. The whole bed of material starts to shear off and I quickly find the tractor in a drastic crab to move across the hill. It isn't as bad with just grass, but still noticeable.

I don't feel like the bar tires are really the best thing for a slope. I would like to try it with field trax or with the tires that come stock on the Aebi, on the outside to see if it was any better...

 

[woodlandfarms]

Wow, your property looks great. Super Jealous. I am thinking of welding a handle on the ROPS right where your hand is. A nice " O sht" handle.

 

[MossRoad]

I've thought about welding a handle onto mine as well. I usually just grab the ROPs post, but once in a while, I'll run into a branch and scrape my fingers off the post. If there was a handle inside the ROPS, it would save my fingers.