It's PT 435 tire time.

[Gravy]

Long time no talk. My Subaru Robin EH90 (aka Generac GTH990-ish) engine swap in my 2006 PT425 is still going about 8 years later. But the Carlisle All Trail tires that I bought a number of years ago are coming apart. The tread knobs are barely worn down at all. But on two of the tires, cracks have developed at the base of the knobs, and air hisses out. I'm not unhappy with the tires. They've lasted longer than either the Carlisle Super Lug or Turf Trac tires that I tried before them. But I'm hoping to find something with better traction. My property has lots of steep spots, and the "soil" is generally crumbly decomposing rock of various types, and doesn't support deep root growth for any grass that may have the temerity to attempt to grow on it, so there is really no turf with a root network to hold it all together. It's all quite fragile.

So, I'm hoping to find some magical tires that will actually have better traction on these slopes than the ones I have mentioned, and will dig in and move the PT forward and upward rather than just spinning and ripping out any grass by the roots. Aside from the tires I've already mentioned, I've run across references to some ATV tires and new reproductions of Firestone ag tread/lug tires. Has anybody found something that has exceptional traction on loose, steep surfaces? Even running tire chains all year didn't work very well.

I'm hoping somebody will dope slap me and point me to something everybody else here knows about.

 

[MossRoad]

Sorry I can't help. I'm still on the original turfs (well, 3 of them. I destroyed 1 myself) that came with the machine in 2001. Got about 600 hours on them with very little wear.

 

[ponytug]

I don't have a 4XX. So, I may be totally off base, but here goes.

FWIW: I have a 1445, with R4 tires, and during our wet season it has four wheel net chains. I'm often on 25-30 degree slopes, and I've noticed that the R4 tread slips on loose surface material (e.g. gravel, wet sap) on steep slopes. I've tried a variety of tire pressures that have no effect on those stiff tires. Chains help a lot, but at the cost of more ground tracks, and occasionally divots from spinning a wheel.

I think that the low ground pressure of the PTs that make them so good at floating over grass and soft soil also makes traction sensitive to the contact area. So, slick grass, wet sap, loose gravel causes reduced friction and reduced traction because the PTs "grip" just the top layer because they aren't sinking in, unlike typical tractors. I think regular lawn mowers are designed for pretty flat lawns, so I tend to ignore spin outs on slick areas, because not much happens.

I'm not sure that there is a magic tire tread, or we'd all be using it. I suspect that lawn tires (R3), which have the largest contact, area are probably the most sensitive, but I'm not sure that R1 or R4 would help that much. I'd try chains first. There are some Carlisle deep lug R4s ("Xtra Grip"), but I have not yet tried them. Like @MossRoad I am still running on my originals.

All the best,

Peter

 

[m5040]

You may want to try R14 tires, they are like a ag tread and turf tread combined in one.
Be careful when shopping ATV tires, they might not hold the weight.

 

[Gravy]

Thanks, guys. I'm currently running Carlisle All Trail HDAP tires, which wear like iron. They are aging out with cracks in the rubber, slow leaks and other deterioration, but the knobs are still probably 75% of new height. I'd say they had significantly more traction than the Turf Savers, especially in snow (back when we got enough to plow), but the difference wasn't dramatic. Somewhere in there I went through a couple of sets of Carlisle Super Lugs. Other than deep mud, I can't really say they had great traction either. All three of those types of tires pretty much lost traction in the same places.

My "soil" is really fragile, being crumbly when dry from lots of decomposing stone in with the clay, and greasy when wet, except where I have added enough organic material over the years. The soil is also extremely rocky, and the big smooth ones that are more or less flush with the surface have terrible traction. At this point I'm considering Carlisle Tru Power and Firestone Flotation 23 lug tires or some hypothetical gnarly heavy duty ATV/UTV tire. The Firestones are apparently THE tire for stock class garden tractors in pulling competitions, which is a point in their favor, but I'm still going to investigate ATV/UTV tires since there are a lot of choices that are optimized for various conditions. Our old 2wd 4-wheeler can just calmly motor up slopes where the PT spins tires and struggles to make forward progress. I suspect the knobby tires have something to do with that.

 

[2manyrocks]

I suggest you use the search tool to look for posts by KentT regarding his PT425 that he was using to mow in the East TN mountains. He upgraded his wheel motors to larger ones, and eventually went to using a 1430. But it sounds like you are going through similar issues, and perhaps some of his thoughts would be helpful to you.

Question for you guys running tire chains on hillsides

Are you using the more common 2-link V-bar chains, or what? Do you have problems with them getting down between the lugs on the R-1 ag tires? I've only used tire chains on ags up north, using a snowblade or snowblower, and this is a different application. In fact, I have a couple sets for...

www.tractorbynet.com

 

[Gravy]

You may want to try R14 tires, they are like a ag tread and turf tread combined in one.
Be careful when shopping ATV tires, they might not hold the weight.


View attachment 919434

That looks like it could work. Unfortunately, they don't appear to be available in a 23-10.50-12 size.

 

[Gravy]

I ended up with Carlisle Tru-power lug tires. After lots of googling, I came to the conclusion that they should be the second most aggressive lug tire in my size. The reproduction Firestones are #1, but they would cost $1000 for a set with shipping from Miller Tire, where the Tru Powers were $480 from Amazon.

The TPs look a lot more aggressive than the Super Lugs that PT used to put on the PT425, with a very squared-off profile and heavier lugs, so I'm hoping they will work better than the rounded profile SL. Carlisle no longer sells the SL in this size, anyway.

 

[m5040]

Pictures when you get it done please

 

[Gravy]

I found it interesting that the tires are also labeled with an automotive size. They ride noticeably stiffer than the All Trails, despite both being 4-ply.