# Tire size/rim size questions.



## JD3430 (Jan 1, 2012)

Found a Kubota M-135X I'd like to buy. The tires are shot. It came with 480/80/R38's on back and 14.9/R24's on the front.
I'd like to replace them with the optional wider tires package kubota offered for this tractor.
The wider tire package is 520/70/38 rear and 420/70/R24 front.

I cant seem to get a good answer on if the RIMS are different if the wider tires are opted for. I'm pretty convinced the rims for the wider tires are also wider than the rims that come with the standard width tires.
My tire guy thinks I'd "be OK" with the rims on the tractor now (16" wide rear and 12" wide front). However, one Kubota parts guy says they're wider when the wider tires are ordered. A second Kubota parts guy I spoke with says theyre the same.

Anyone in the know for sure? I don't like "I think they'll be OK". I like "they're the correct rim width" better.

Or maybe more easily asked:
Rim widths for:
480/80/38
520/70/38
14.9/24
420/70/24?


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## paoutdoorsman (Apr 23, 2016)

If the Kubota illustrated parts catalog is to be trusted, the rears are both 38x16. Interestingly however, the part numbers are different.

520/70/38









480/80/38 / 18.4R38


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## paoutdoorsman (Apr 23, 2016)

3 Different tire options show for the front. All with a 24x12 wheel, but again with two different part numbers.

13.6-24









14.9R24









420/70R24


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## JD3430 (Jan 1, 2012)

Crazy!!!!
Why? Is it possible the part number changes when its paired with a different tire???


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## paoutdoorsman (Apr 23, 2016)

Any chance the wider tire option automatically includes a cast wheel center vs. a steel wheel center? The part numbers I highlighted are for the rim only. Maybe there is a different rim for a cast center vs steel center.


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## JD3430 (Jan 1, 2012)

The unit I'm looking at has cast center rims, but the standard 480 tires


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## Gearclash (Nov 25, 2010)

Every tire manufacturer worth their salt lists both the preferred rim size and also acceptable rim sizes for a given tire model. As a general rule, a 480/18.4 goes on a 16" rim, and a 520/20.8 goes on an 18" rim, but there can be exceptions to that. Tires of European origin are maybe more likely to spec a narrower rim. Usually the size of the rim is stamped somewhere on the rim itself. Best thing you could do is lay eyes on tractor that has the wider tires as OEM and see what the rim sizes are.


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## JD3430 (Jan 1, 2012)

Gearclash said:


> Every tire manufacturer worth their salt lists both the preferred rim size and also acceptable rim sizes for a given tire model. As a general rule, a 480/18.4 goes on a 16" rim, and a 520/20.8 goes on an 18" rim, but there can be exceptions to that. Tires of European origin are maybe more likely to spec a narrower rim. Usually the size of the rim is stamped somewhere on the rim itself. Best thing you could do is lay eyes on tractor that has the wider tires as OEM and see what the rim sizes are.


Yeah I already thought of that and I agree with you, but there isn't one anywhere around here.

Did a little more digging and I googled "BKT Agri-Max 520/70R38" and Petes Tire Barn has them. Lists rim as a "W16L 38" which I assume means 16x38 is preferred rim. Optional rim is W15 38 or W18 38.
Then I googled "BKT Agri-Max 420/70R24" and again, Petes Tire barn has them. Lists rim as W13 and opitional W12, W14, which again I'm assuming means a 13" width is the desired width and and an optional 12" with or 14" width will work.
From that information, it looks like if I bought BKT's, I'd be perfect on the existing back rim at 16" and using one of the optional (smaller 12" optional) rims on the front.
Do I have my bomber over the target? Or am I all wrong?


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## woodland (May 23, 2016)

Our Deere's run 20.8/520 radials on 18 inch rims but I would think 16 inch would work too. You will really like the bigger rubber as our neighbor had a 4440 with shot 20.8 bias tires and the tire shop talked him into 18.4 radials. They changed them just before straw baling time and it was a disaster. I was running it and it would spin out easier on the hills than our 4430 and the drawbar was too low and would keep bunching up the straw to plug the baler. Two days later it had 20.8's again but I'm unsure if they changed rims for this. I was 15 at the time so that's 19 years ago. Time flies????

Adrian


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## Coondle (Aug 28, 2013)

JD3430 your bomber is indeed over the target. Tyre manufacturers list tyre sizes and acceptable rims.

eg Michelin link is:

www.ntstractortires.com/assets/uploads/pdf/tires/MichelinData.pdf

and there it is suggested a DW16L

DW stands for Double Well on a 16 inch wide rim and L is the flange code.

In the same document a 420/65/24 requires a W11 rim.

To answer your first question the rims you have at 16 inch and 12 inch should fit your proposed tyre sizes. The only question is the "DW" but that affects the ease of fitting not the suitability of rim width.


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