Tires Upsized front r4 tires on L5030

[slowzuki]

The MX5100 actually have a different ratio in the front diff and the side gears. The rear end on them is based on the older L4610 design without the external lift cylinders that have a different rear ratio and lead/lag mechanical ratio.

Never understood why L series used the smaller R-4 size. My MX 5100 is comparable in size and 12 x 16.5 is the standard R-4 front tire. The footprint of the 10" width would seem to exert excessive ground pressure on improved landscape surfaces, especially in using the FEL, loaded to capacity. Shortsighted thinking on Kubota's part ?. Other manufactures of this
size tractor seem to employee the 12" R-4. (Mahindra, an example) The L series rear tire sizes on L and MX are the same for Industrial Tires.

 

[majorwager]

Slow,
My post did not include reference to ratios. The comment dealt with the compaction aspect of a 10" width tire. As for the MX design based upon an old L series, I do Not accept your premise, actually Messick's produced a video differentiating the Cat 1 of the L from the Cat 2 of the MX. The MX axle is inherently more robust. It isn't a convoluted regurgitated concept of the past. Further, the design of the 3 point lift mechanism has no relationship to the final drive ratio.

 

[FatTire]

L5740 and MX5100 front tires.

 

[slowzuki]

not trying to be negative on the MX, I like them. The front axles are 90% the same as the L30 except a few gears. This means they have the good steering and top bolster on the knuckle.

The rear end design is the older type series without the external lift cylinders. The Grand L10 series had a split where the L4610 got the new style front end that later Grand L and MX inherited. The L4610 also retained planetary gears of the older L while the L30 went to cheaper spur gear design that fit the lift cylinders better.

So the MX has better front axle, and retains strong planetary rear, just doesn稚 have the 3 point lift numbers the external cylinders provide.

Slow,
My post did not include reference to ratios. The comment dealt with the compaction aspect of a 10" width tire. As for the MX design based upon an old L series, I do Not accept your premise, actually Messick's produced a video differentiating the Cat 1 of the L from the Cat 2 of the MX. The MX axle is inherently more robust. It isn't a convoluted regurgitated concept of the past. Further, the design of the 3 point lift mechanism has no relationship to the final drive ratio.

 

[1stDeuce]

Slowzuki, someone asked a ways back if you ran the 12-16.5's on the original 10-16.5 rims or if you changed out the rims... I too am wondering about this, as I have a MF that I'd like to bump the front tire size on. It's got little to no lead with 10-16.5's, and I generally use 4wd only for loader work with lots of turning, so if I end up just a little high on lead, it's not an issue.

I am just wondering if you were able to cram 12's on the front rims that originally were sized for 10's. I think a normal 10 rim is about 8.25" wide, while the standard wheel for a 12 would be 9.75" wide... I wouldn't worry about running a narrow rim on a truck tire, but not sure how these skidsteer tires will like it...

Thanks for the info!

 

[slowzuki]

The original rims work fine.

The R4’s I swapped to are 16.5-12 not 12.5’s.

 

[slowzuki]

And I noticed above, my comments on the MX5100 are actually the MX5000, sorry about that. I’ve not looked at the MX5100’s in detail. I presume they had next tier emissions and the sleeker hood.

 

[slowzuki]

Last update, take a look at the R1 tire options on the MX5100 vs the L5030 or 40 series. They run the same 9.5x16 and 14.9x26 or 13.6x28 rears. The R4 option bumps the fronts to 12x16.5 on the MX5100 where it didn’t on the L5030.

 

[1stDeuce]

Thanks Slowzuki! I corretcted my questions... Not sure why I had the .5 in there... Brain fart I guess.
I'll be upping to 12's next re-shoe...

Interesting that Kubota runs the larger R4, but the same size R1's on the MX5100... My tractor used 9.5-16's on the front with R1's also, but only 10-16.5's with R4's. I don't remember the size, but the rear R1's were not as much larger as the fronts, meaning with R1's, there was quite a bit of front lead, while with R4's, there is little to none. Perhaps more lead works better in places you would typically use 4wd with R1's, or the taller tread will squirm and forgive a bigger amount of lead...

How exactly are you fellas determining how much lead there is, anyway? I have no idea the front to rear gear ratio of my tractor, and don't know how I'd ever figure it out w/o taking things apart to check gear count... ?? I can only guess based on how quickly it binds up going straight on a firm surface...

 

[dantran1010]

EPIC FAIL! I upsized from the 10-16.5 to 12-16.5. Common sense should have prevailed but stupidity got the best of me but I guess :confused3: I was too busy wasting $$$ and time. Installed the 12’s put it in 4wd on loose dirt and absolutely not good! Just ordered the 10-16.5’s. Let me know if anyone needs a new set of 12’s :thumbdown:

 

[FatTire]

Binds up badly?

 

[dantran1010]

Yeah, it binds/screams...

 

[1stDeuce]

So the OP did it to his L5030 and it worked fine for him, but your L5030 binds up "badly"?
Are your rear tires worn?
Are they the standard 17.5-24 size?
Are they loaded? (That would keep them from scrubbing as easily, making any bind much more noticeable...)

I did notice that 10 or 12 ply versions of 12-16.5's have a noticeably higher rolling circumference than the 6 and 8 ply tires...
What ply rating did you go with?

The OP also said that he mostly works in soft terrain, and runs fairly low pressure in the front tires... If his rear tires aren't loaded, they'll slip easier, and having low pressure on the fronts would reduce the rolling circ. If he's using 4wd with the loader, and turning a lot in doing so, excessive lead would also not be a problem, since the front tires must travel farther when turning.

BTW, unless it's very loose, a gravel drive or road can certainly be a hard surface when it comes to traction...

 

[dantran1010]

So the OP did it to his L5030 and it worked fine for him, but your L5030 binds up "badly"?
Are your rear tires worn? No
Are they the standard 17.5-24 size? Yes
Are they loaded? (That would keep them from scrubbing as easily, making any bind much more noticeable...) Not loaded

I did notice that 10 or 12 ply versions of 12-16.5's have a noticeably higher rolling circumference than the 6 and 8 ply tires...
What ply rating did you go with? 10 ply 33.01”

The OP also said that he mostly works in soft terrain, and runs fairly low pressure in the front tires... If his rear tires aren't loaded, they'll slip easier, and having low pressure on the fronts would reduce the rolling circ. If he's using 4wd with the loader, and turning a lot in doing so, excessive lead would also not be a problem, since the front tires must travel farther when turning.

BTW, unless it's very loose, a gravel drive or road can certainly be a hard surface when it comes to traction... I was on very loose millings test in 4wd.

 

[1stDeuce]

20 ply??? For real? I hadn't seen tires higher than 14 ply, and for a CUT, 6 or 8 ply would be plenty...

The published height of the tire is not as important as the loaded rolling circumference. Ideally, you would want to choose a 12-16.5 with the lowest rolling circ if you were upsizing. I see Titan at 101', and Carlisle at 99.7. Doesn't sound like much, but that's a 1% difference, and when you're talking lead, everything counts. Even just running them so they have some sidewall flex probably provides another % or two...

It looks like making this switch for my tractor, and staying with 6ply titan Trac Loader tires would provide an 8% change in lead... Using a 6 ply Carlisle tire instead would provide a 7% lead change. Running the tires at lower pressure, I can probably get rid of another 1-2%, bringing me down to theoretical 5% change...
I played with the tractor again last night, and it appears that it is ever so slightly pushing the front tires in 4wd, they are not leading... I think even a 7-8% change would be OK for my tractor...

If a person wanted to counter the front lead change, you could also bump from 17.5-24's to 16.9's. That would provide a 4-5% increase in rolling circ for the rear that would mostly cancel out the increase in front rolling circ... It would also level the tractor back out some, which would be good for the loader.

Still, bummer that it didn't work out for you...

 

[dantran1010]

20 ply??? For real? I hadn't seen tires higher than 14 ply, and for a CUT, 6 or 8 ply would be plenty...

The published height of the tire is not as important as the loaded rolling circumference. Ideally, you would want to choose a 12-16.5 with the lowest rolling circ if you were upsizing, thought it appears that both Titan and Carlisle are right around 100" with their 12-16.5's...

Still, bummer that it didn't work out for you...

10 PLY, TYPO! :shocked:

 

[rScotty]

Too bad it didn't work out. I guess you are 2wd for awhile. Binding & screaming in 4wd is clearly a case of your tractor yelling a warning to your bank account.

Might as well get some loaded rolling circumference (RC) measurements while the tires are mounted. Then you will at least have some more info. I think your idea was good, but tires wrong.
Easiest way to get RC measurement is to find a hard surface, put a dab of wet paint on the tire tread, and drive a few hundred feet. Get off, go back, use a tape measure to find average distance between paint spotches on the ground. The distance covered in one tire revolution is your loaded rolling circumference. It's good information to have.
rScotty

 

[slowzuki]

I'm very sorry to hear this, I ran them for years/ hundreds of hours without issue. Loaded rear tires, loader on the front. Still have the worn out R4's on rims out in the tire pile but swapped to 15.50 wide R1's a couple of years ago for more floatation, they are about 33" tall. These do bind/whine a bit on pavement, fine on dirt or in the field. Tractor has around 3000 hours on it now, the original rear R4's are down to only about 1/2" tread now so keeping an eye out for new rear tires soon.

EPIC FAIL! I upsized from the 10-16.5 to 12-16.5. Common sense should have prevailed but stupidity got the best of me but I guess :confused3: I was too busy wasting $$$ and time. Installed the 12ç—´ put it in 4wd on loose dirt and absolutely not good! Just ordered the 10-16.5ç—´. Let me know if anyone needs a new set of 12ç—´ :thumbdown:

 

[majorwager]

Dantran,

You are not the first to report a failed result w/ this same upgrade, It is one reason I chose an MX over the L series kubota.

A similar post appeared just last year. Tire dealer might exchange them if it was NOT an on line purchase,

 

[slowzuki]

I'm beginning to wonder if there is a serial number break where they fixed the lagging front axle ratio the L5030's had with R4's. My L5030 is an early model. Mine used to bind badly with the original R4's.

Dantran,

You are not the first to report a failed result w/ this same upgrade, It is one reason I chose an MX over the L series kubota.

A similar post appeared just last year. Tire dealer might exchange them if it was NOT an on line purchase,