5425 vs 4320 vs 3720 Surface Pressure

[scrappy isb67]

Per square inch . A 2000 or 10,000 lb tractor with 10psi in the tires will push on the soil with 10lbs force on every square inch.

nope That is accurate only if the tire contact patch on the 10K tractor is 5X the size of the contact area of the 2K tractor.

Actually keeping 10psi in the tires and doubling the weight each tire is carrying will double the contact area with the ground. Just eyeballing the tire sitting in dirt doesn't show everything that is happening. Roll the tire onto polycarbonate then watch the contact patch increase or decrease as psi and/or weight is varied.

only true to a point. at that point the contact patch will get SMALLER because the tire is flexing the center of the tread AWAY from the ground.

So as the starter of the post, thank you for the enlightening discussion.

My Question still stands.

If I put the appropriate sized R3 Tires on my 5425 will it be as easy on the lawn as a 3720 with R3's?

see my response to the first quoted post.

Keep in mind the 64 psi tire is carrying 50% more weight
Also the belt construction of a bias tire .
Plus lets compare the flat plate pressure vs. 3" penetration pressure.
One can easily start comparing apples to oranges.

but the contact pressure went up 62% to carry that 50% percent larger load.

 

[Piston]

The way some of you are explaining this tire pressure nonsense makes it sound like your saying that tire pressure equals ground pressure. I hope that isn't what you really mean or believe, because based on that logic, the op could simply deflate his tires to 0 psi and have a magical floating tractor that exerts zero ground pressure.

 

[LD1]

The way some of you are explaining this tire pressure nonsense makes it sound like your saying that tire pressure equals ground pressure. I hope that isn't what you really mean or believe, because based on that logic, the op could simply deflate his tires to 0 psi and have a magical floating tractor that exerts zero ground pressure.

That is exactally what they are saying. But not me.

 

[bucktaker]

To the Original OP

There are more tire options than r1,r3,r4 You might investigate the special turf tires like what are run on golf courses and turf farms. Might be as simple as a summer set of mowing tires and your original r1's for winter work much cheaper even if you have a tire service mount and dismount twice a year

 

[morrisond]

Are there any good places I can find pricing for rims and tires on-line?

 

[bucktaker]

try googling Flotation tires or go to a ag tire shop ti find what works for your tractor maybe a JD dealer can point you in the right direction for tires that will provide min turf distrubance

 

[buickanddeere]

The way some of you are explaining this tire pressure nonsense makes it sound like your saying that tire pressure equals ground pressure. I hope that isn't what you really mean or believe, because based on that logic, the op could simply deflate his tires to 0 psi and have a magical floating tractor that exerts zero ground pressure.

Tire pressure isn't zero once weight is applied. It's a complex set of dynamics . I run zero psi in the atv tires on my lawn tractor when jacked off the ground. Install the valve stem cores and caps them lower tractor to floor. Using the tire pressure gauge the tires now read 1psi iirc. If we really want to examine the issue. Let's consider not just the static ground pressure that a non driving tire exerts. Then consider a driving wheel with linear thrust and static weight. That btw is where duals really benefit to widen the contact patch and limit compaction

 

[Piston]

Okay so take the valve stem out and operate like that. Or better yet, take the tire off completely and run the tractor on the rim. Walah, back to the magical floating tractor.

Like I said, that's the way it sounds, however to be fair (I'm just having fun ) I'm sure there is some sort of good physics explanation that has something to do with the correlation. But I'll admit I don't know either.

As mentioned, the best thing to do is get high flotation tires to ensure the least disturbance. May also invest in a turf aerator for aerating once a year and your all set.

 

[charleyfarmall]

So let's try this again.

Imagine the tire is a boloney skin for simplicity. Inflate it to 10 psi. That means every square inch of tire has 10 pounds pushing on it.

Put on the tractor, and set the machine on the ground. Every square inch of tire still has 10 pounds pushing on it. That includes the tire that is in contact with the ground.

The tire will deform until the tractor is supported and every square inch of tire has 10 pounds pushing on it. The total weight per tire will be proportional to the weight of the tractor and the weight distribution front to rear, side to side. The pounds per square inch of contact remains the same.

You can't go to zero because the tire is no longer supporting the tractor and you get a divide by zero error

The tread pattern is going to affect behaviour which is why the R1's sink in until the casing hits the ground. The R3 is the closest to a boloney skin and causes the least amount of damage.

R1's cause more soil compaction on the larger tractor because the bar sinks in with higher pressure until the contact patch levels out and the pressure is distributed.

 

[buickanddeere]

Okay so take the valve stem out and operate like that. Or better yet, take the tire off completely and run the tractor on the rim. Walah, back to the magical floating tractor.

Like I said, that's the way it sounds, however to be fair (I'm just having fun ) I'm sure there is some sort of good physics explanation that has something to do with the correlation. But I'll admit I don't know either.

As mentioned, the best thing to do is get high flotation tires to ensure the least disturbance. May also invest in a turf aerator for aerating once a year and your all set.

What are you possibly talking about ? Who is driving around without valve cores in the stems? Driving on rims and floating tractors? Are you daft? Why are you avoiding the issue and physics then running off with some complete and total falsehood as if it's truth?