Tire Selection School me on tractor/tire width

MAD777 · Aug 29, 2017

I'm currently building a home on a sloped, wooded property & researching to buy a tractor. Through this forum, I've been able to understand what to look for. However, determining the width of a tractor whose specs show different tread widths vs tire types has me thoroughly confused.

The following items include a clip from a tractor spec sheet where I've circled the tire size and tread width. As I understand it, tread width is the lateral distance between the center point of the tires.

In the second item below, I've added the tire width to the tread width to determine the total with of the rear of the tractor. I'm not sure if I've done this correctly.

If my results are accurate, this shows a significant difference in total width, therefore significant differences in tractor stability depending on the choice of tire types.

On my wooded, sometimes wet land, I need good traction, which would point me to Ag tires, but due to my sloped land, stability is also an important consideration. So, I'm wondering if my calculations are done correctly.

CincyFlyer · Aug 29, 2017

Yeah, turf tires do indeed give you a wider track (that's the automotive term for it) and they lower the tractor, a two-for-one towards more stability. They also are much easier on grass! But like you, my few acres are hilly and can be muddy for several months of the year, so I had to go with ags. I'm keeping my eye out for a set of suitable turfs on wheels, however!
Edit: for my tractor, the turf tires on the proper rims are much wider track than the ags. The industrials appear to be very wide in your example; I'd get with the tractor dealer and see if you can get some actual measurements (and note that rim offset can often be changed with any type of tire.). Industrial tires may be a decent compromise for you. Me殆ell, I've gotten a 4wd tractor stuck in the mud with ags. Hopefully after my current project there won't be any more areas where that can happen.

crmorse · Aug 29, 2017

I've got similar land and since I got an L47 Ags aren't even an option. I appreciate the extra strength of the R4s but they absolutely suck in mud. My 2WD 8N with Ags (20hp on a good day) will out pull my 50HP 4WD L47 easily if there's any mud to be had. If R1s were an option, I'd do it. Look for wheel spacers or whatever other tricks are available and fill those tires and I think you'll be happy.

jeff9366 · Aug 29, 2017

Tractor widths in brochures always are with R1/ag tires. Ag tires were "first" and that is the convention.

R4/industrial tires will always be a little wider.

Most of us with RESIDENTIAL use tractors do not work on wet days. We wait until land drys out.

If clearing a drive of snow will be a regular task the average amount and average depth of snow falls should be an important input to tractor tire selection.

MAD777 · Aug 29, 2017

Thanks for all the comments. Everything is helpful since this will be my first tractor.

Some areas of the property stay wet and unfortunately, that area is centrally located so I have to navigate that.

Oh yes, there is snow. White Mountains of New Hampshire with a 400' gravel driveway. I've accepted chains as a reality during winter.

LD1 · Aug 29, 2017

Ag tires are almost always adjustable, and usually to just as wide, if not a tad wider than the r4's or turfs.

The listed width for AG tires is almost never the max, rather something middle of the road how the tire comes set up.

Most tread width options for ags are listed in the operator manual. Usually about 6 different options in 2" increments or so.

Perhaps list the models of tractors you are interested in, and members here can take a picture of the page in their manual that lists all this info.

I have manuals for Kubota L3400 ( which should be the same as the L2800,L3200, L3700, L3301 and L3901)

Also have manual for my Mx5200. Which should also be the same for the rest of the MX tractors.

I'd be happy to offer a pic of the manuals when I get home, if either of those are contenders on your list

MAD777 · Aug 29, 2017

I take it these adjustments are common. Now I know what to ask of the dealers I visit.

So, I should get the tires that I need for traction, and adjust the width for stability. Sounds like Ag tires with spacers.

LD1 · Aug 29, 2017

MAD777 said:
So, I should get the tires that I need for traction, and adjust the width for stability. Sounds like Ag tires with spacers.

That's what I would do. But I'd hold off on spacer unless you really think you need them. Set the tires in their widest position first

jeff9366 · Aug 29, 2017

MAD777 said:
So, I should get the tires that I need for traction, and adjust the width for stability. Sounds like Ag tires with spacers.

1. R1s are usually four ply. Available in six ply and eight ply. The flexibility of four ply provides largest tire patch on the ground and greatest traction. R1s can imprint turf. R1s provide a rough ride when traveling over hard surface roads at speed.

2. R4s are usually six ply. Available in eight and ten ply. More plies better support heavy FEL loads. No tire squashing. Most using tractors with loaders opt for R4/industrial tires. R4s provide a relatively smooth ride when traveling over hard road surfaces.

3. Many tractors with loaders visit a burn pile regularly. Around a burn pile the greater puncture resistance of R4s should be considered.

4. Loading rear tires 3/4 with liquid lowers the center-of-gravity of the whole tractor. Rear tire liquid should be installed before spacers are considered.

5. Most "standard" tractors do not have adjustable rear tire widths.

You can purchase 3" spacers for each side for light tractors. As tractor weight goes up, spacers decrease to 1-1/2" per side due to need to support heavier tractor loads. Spacers are more cost effective on light tractors. There is an installation fee for spacers as wheels must be removed.

Spacers for light tractors are $300 a pair from Bro-Tek, plus installation. Spacers for ag tractors are $600+ a pair from Unverferth, plus installation.