Wide Front tire options?

[Dan Tarnowski]

Hi All, I have a L5740 with R4 tires on it. The fronts are 10-16.5
Does anyone have a good suggestions for a extra wide front tire option? Preferably something 15-16 inches wide.
I am looking for better flotation on soft spongy sod. Once the fronts break through, its game over.
All of my tires on the tractor are original. While the tread is good on all of them, they are all weather checking pretty bad, so replacing them isn't a big deal.
From what I can find online, my fronts are 30.8" in diameter, and as this is a 4x4, I need to keep this close. I also need a decent load rating for the FEL.
I thought before I try an re-invent the wheel, I'd see if anyone here has tried something similar.

 

[Dan Tarnowski]

Ok, I have done a lot of digging (and educating myself!). From some information I found on this site, I have a 1.564 gear ratio on my tractor. Now what I am struggling with is which numbers do I use for my lead/lag calculations? Titan has an online calculator here: Lead Lag Calculator (titan-intl.com)
Their calculator says to use tire rolling circumference. However, rolling circumference is not listed for some of their tires. (HD2000 II). When I look at their industrial tractor lug tires, they list both static loaded radius and rolling circumference, but normal math doesn't work out correctly for these two numbers.
(2 x pi x static loaded radius does not equal rolling circumference?) Depending on what numbers I use, I get different answers, some within acceptable range (0-5%) on some not?

 

[North Idaho Wolfman]

There are several negative and expensive results that very likely could happen by widening the front tires, especially using a FEL.
#1 The stress and wear on the bevel gear case will increase triple fold.
#2 The stress and wear on the differential will increase.
#3 The stress on steering will increase.

Yes each tire type and brand will have different variables.
The issue is some are softer / squish more than others thus the numbers change with loading, you're original round tire turns into and elliptical tire.

 

[GrizBota]

I’d think at the low speeds tractors are operated while working (probably under 5 mph for FEL work), that centrifugal force would not significantly increase the rolling radius relative to the static loaded radius. Can you tell us which value is slightly larger than the other?

if the rolling radius is stated as slightly smaller than the static loaded radius, my guess is the rolling radius has an allowance for the tire lugs being slightly engaged with the ground (e.g. a non hard surface).

Regardless the reason, obviously 5% in circumference (or radius, or diameter, the math works out the same percentage wise) will make a difference in the front tires lagging or leading, so I think you’re right that is worth figuring out.

As to the additional loading imposed on bearings, gears and steering, if the back spacing of the new tire/wheel set up can be provided such that the additional width of the wider tires is biased towards the center of the tractor, that can offset some of the additional loading.

 

[Dan Tarnowski]

It's obvious there is no simple answer for this. Part of the problem is that it's neigh impossible to get consistent data for any given tire. There are several online sources that list the same tire with different specifications. I have seen load capability vary by over 2000# between sites. Assuming that the manufacturer has the most accurate data, I found this Titan PDF. (See attached) Using my actual mfg #'s from the tires, my fronts are 4123C8 and rears are 4D6603. Both can be found in the titan PDF. Stated rolling circumference is 93" for the fronts and 145" for the rears. Using my gear ration of 1.564, this equates to a 0.31% lead. Certainly within the 0-5% recommended lead for FWA tractors.
However, slight variations in rolling circumference can affect this lead/lag. I have calculated -1.81% -4.78% depending on what is to be believed for rolling circumference.
There are formulas online that that calculate rolling circumference, but much of what I see published, I'd take with a grain of salt, as I believe they are for automotive applications. The "squish" on a passenger vehicle is not the same as our implements. One source stated R.C. (rolling circumference) = pi*O.A.D.(overall diameter)*0.96.
Picking several different tires from the attached Titan catalogue, and comparing the listed O.A.D to R.C., I have found that R.C. was between 0.89 to 0.92 of O.A.D. Tire dependent.
One other thing to point out: in the Titan book, all R.C. appear to be rounded to a whole number. Every online source I looked at carried out the R.C. to at least one decimal point.

Bottom line is I think there is some fudge factor based on a number of variables.
The only true R.C. would have to come from the mfg. with strictly controlled variables (air pressure, load, ply rating, ground conditions, temperature, wheel width...)

I appreciate both of your inputs.
I want to follow up in another post with the direction I am thinking of going.

 

[Dan Tarnowski]

So, here's where I am at: All 4 of my existing tires are 15 years old and very weather checked. They still hold air, but you can almost see the air through all the cracks. I have a bunch of work I need to do on wet sod. I have already tore a lot of it up, but I want to try and save what's left. Even with no load in the bucked or on the forks, the front tires would squish up the sod pretty good, multiple passes combined with passes with a load resulted in breaking through. I wanted to try something wider in the front to start with. I also want to add that from day 1 my tractor took a little rocking to get in and out of 4wd pending on the surface I'm driving on, pretty typical for these tractors.

I think I want to try a set of Titan 4S23J7TTF 12-16.5 E TL TGS2 SS Tread "A" tires up front. I can't find a R.C. for this tire, but using the R.C. ranger rule of thumb from my previous post of 0.89 - 0.92 * the mounted diameter of 33.04", I calculate a R.C. range of 92.38" - 95.49", all of which are within the 0-5% lead recommendation when I use an R.C. of 145", the published value from Titan for my existing rear tires.
I would be changing the width of my front tires from 10.9" to 13.26", an increase of 21.7%, not terribly drastic, but should help with the flotation issue. I have no problem with the turf style lug, an d I believe the tread and siping will help dramatically for winter snow use. (Northern Mn. climate.)
I will have to get some wider rims for these tires. I believe I can order a set of TC050-00790 Kubota wheels. (16.5x9.75)
I need to get some pricing and availability. If/when I get this done, I'll be sure to post an update as I am sure there are others out there who would like to accomplish the same thing,

 

[GrizBota]

Indeed, significant figures are limiting the validity of the calcs when the RC is reported to the nearest inch. Say that the rear tire is actually 145.49 inches vs 145 inches, the calc goes from a 0.31% lead to a 0.03% lag. But it’s all “noise” because one can not increase accuracy of a computation by carrying out decimal points the original data doesn’t have. Now if I could just get my technicians to apply this logic consistently…

Wishing you the best with finding a good solution.

 

[GreensvilleJay]

I'm curious as to why the sod is 'soft and spongy' ?
Is this a 'forever ' problem or just seasonal ?
One little area or 100 acres ?