R1 to R4 tires on a Kubota L4400?

[cpainter]

Guys, the original rear tires are about shot on my 2011 Kubota L4400. The original tires are R1's: Front: 8.3-16, Rear: 14.9-24. I live in a rocky area of central Texas and the rocks tear up the tread very quick. I'm thinking that industrial tread would hold up better. What would you fellas recommend?

 

[jeff9366]

R1 ag tires are four ply.

R4 industrial tires are at least six ply. 50% tougher. Some traction loss relative to R1's pulling over soft or moist ground. Not much traction difference pulling over adobe brick. (Eight and 10 ply R4 tires are fairly available.)

You will need replacement rims to fit less tall R4 tires.

 

[old and tired]

You can get Ag/R1 tires with more ply, 6, 8, and 10 ply. Do you need help with mud (because R4 suk bad in muddy areas). Industrial/ R4 are pretty tough with rocks...

There is also now R14's but I don't know anything about them...

 

[LouNY]

You can get a 14.9-24 in the R4 class of tire how the loaded radius compares to the R1 I didn't look up and then it would be a matter of getting the correct height tire to match up with the rears.

 

[cpainter]

Ok, Here's what I found for the size industrials that would have come on it:

Where can I find info on the loaded radiuseseses of different tires?

 

[LouNY]

Most tire manufactures have a very good data table for there tires;
this link is to a Titan tire web page that has all of there 14.9-24 tires, R1, R4's and even R14's;
Products

a screen shot of the page, clicking on an item in the left column will take you to a detail of that tire,

 

[rScotty]

Ok, Here's what I found for the size industrials that would have come on it:

View attachment 822361

Where can I find info on the loaded radiuseseses of different tires?

To match existing 4wd internal gearing you want to match the existing distance traveled by the front and rear tires. To do that, the spec you want is" loaded diameter", not loaded radius. For oval shapes - not circular - these loaded diameter & radius are entirely different types of measurements, not related, & used for different reasons.
Most of the online tire catalogues will list loaded diameter.

 

[cpainter]

To match existing 4wd internal gearing you want to match the existing distance traveled by the front and rear tires. To do that, the spec you want is" loaded diameter", not loaded radius. For oval shapes - not circular - these loaded diameter & radius are entirely different types of measurements, not related, & used for different reasons.
Most of the online tire catalogues will list loaded diameter.

So, keeping the ratios of mounted diameter the same won't keep me out of trouble?

 

[rScotty]

So, keeping the ratios of mounted diameter the same won't keep me out of trouble?

Well, that's yet another spec.
My guess is that "mounted diameter" would be measured with no weight on the tires.

We are just guessing now, and nothing wrong with that... but my guess is that keeping the front to rear "mounted diameter" ratio the same for the new R4 as it was for the old R1s would be better than not paying attention to the ratios at all.

I assume you are going to do fronts and rears both... and that you already have figured whether the swap will require different wheel rims on both ends as well as tires. I've done a couple of swaps now.

Easiest thing would be to swap with another owner wanting to go the other way. I really like the tougher R4s. Also, R4s run higher pressures than R1s. So it is a stiffer sidewall running more pressure and with a larger wider footprint. More stable on hills, with noticibly less traction in snow and mud but more traction on hard pack dirt and in the rough.

rScotty

 

[cpainter]

Well, that's yet another spec.
My guess is that "mounted diameter" would be measured with no weight on the tires.

We are just guessing now, and nothing wrong with that... but my guess is that keeping the front to rear "mounted diameter" ratio the same for the new R4 as it was for the old R1s would be better than not paying attention to the ratios at all.

I assume you are going to do fronts and rears both... and that you already have figured whether the swap will require different wheel rims on both ends as well as tires. I've done a couple of swaps now.

Easiest thing would be to swap with another owner wanting to go the other way. I really like the tougher R4s. Also, R4s run higher pressures than R1s. So it is a stiffer sidewall running more pressure and with a larger wider footprint. More stable on hills, with noticibly less traction in snow and mud but more traction on hard pack dirt and in the rough.

rScotty

I'm thinking with the following choices, I could maybe do front and back at separate times and be ok...especially if I use 4x4 sparingly on loose surfaces. The rocks where I live take chunks out of the tires, so I'm thinking more rubber contacting the ground, lowering contact pressure, might be a good thing.

 

[rScotty]

Sounds good. You'll know when you try it out. Wind-up in the drive train is real easy to tell because wind-up is what makes it hard to shift OUT of 4wd. Especially with a load in the bucket and in 4wd....

So if it takes force to move the lever to get out of 4wd then expensive parts are being stressed and stretched. Letting us know it is time to figure out another plan before something breaks.

rScotty

 

[LD1]

I have not seen an actual industrial lug tire (like skidloader tires) made for a 16" rim.

Personally I dont like your "possible" option. You are going SMALLER on the rear and LARGER on the front.

The internal gearing of the tractor already OVERDRIVES the front tires. Meaning they spin a little faster than the rears, which is what you want. Your possible option is gonna exaggerate that even more.

As per your chart, the tire options for R1 give you a 1.595 ratio.

10-16.5 R4's that match the 17.5L-24 that kubota specs are a 30.5" diameter tire. 48.8/30.5 =1.60 ratio. A whole lot closer match. But again, requires rim change.

The BTK tires you list for front dont really even look like a true R4, just a heavier ply ag tire. Which you absolutely can do for both front and rear. But if you ever have done loader work on soft ground....I dont think going skinnier on the fronts is a good idea.

 

[rScotty]

So, keeping the ratios of mounted diameter the same won't keep me out of trouble?

I went back to some of the online tire info and cannot find the spec you are seeing for "mounted diameter". But the spec for "rolling circumference" is always there. It is what you want to compare.

 

[cpainter]

I have not seen an actual industrial lug tire (like skidloader tires) made for a 16" rim.

Personally I dont like your "possible" option. You are going SMALLER on the rear and LARGER on the front.

The internal gearing of the tractor already OVERDRIVES the front tires. Meaning they spin a little faster than the rears, which is what you want. Your possible option is gonna exaggerate that even more.

As per your chart, the tire options for R1 give you a 1.595 ratio.

10-16.5 R4's that match the 17.5L-24 that kubota specs are a 30.5" diameter tire. 48.8/30.5 =1.60 ratio. A whole lot closer match. But again, requires rim change.

The BTK tires you list for front dont really even look like a true R4, just a heavier ply ag tire. Which you absolutely can do for both front and rear. But if you ever have done loader work on soft ground....I dont think going skinnier on the fronts is a good idea.

I know what you mean about the front going bigger and the rear being smaller, but I might be in that situation already. I'm on my third set of front tires and my original rear tires. The rears are worn down pretty low, and when I have new front tires on, I'm kind of in that unbalanced situation due to unequal wear. I guess pressure or unbalanced weight loads could have the same effect. I'm not sure how to counter that.

I definitely agree with your observation of the tread design on those BTK R4's. I'm rethinking that option. It's the blockier tread design that I think will help me on the rocks and the BTK's pretty much like the R1's I'm wanting to get away from. I might just have to fork out the money to buy 16.5" wheels to replace my 16's and get a REAL R4 tire. I think I'm ok staying with the original rear wheels and going with a 14.9-24 R4 though...as long as I can source them around here.

Thanks for helping me work through these issues.