L5740 Front Tires Upgraded to Fix Lag Ratio

[greenrider1]

I've been researching tire sizes over the years trying to find a front R4 tire to fix the front to rear lag ratio present on this model (and several others) as they come from the factory with the 10-16.5 front and 17.5L-24 R4 tires. There is a -.43% lag condition with the factory R4's, which is actually bad. The gear ratio for the L5740 is 1.564, and the front tires should lead the rears up to 5%. The Titan 12-16.5 front tires used on several MX models are just a little to tall, with too much rolling circumference, to fall in the 0-5% lead range. What I ended up buying is a set of BKT Skid Power R4 tires. While they are still the 12-16.5 size, they are actually a little smaller diameter (and rolling circumference) than the Titans, which ended up giving me a 4.43% lead. I listed the tire specs below (measurements in inches):

Brand Model Size Diameter Rolling Circumference Width Lead/Lag Ratio

Titan Industrial Contractor 17.5L-24 48.5 142.87 17.3 XX
Titan Trac Loader 10-16.5 30.85 90.96 10.91 -.43%
Titan Trac Loader 12-16.5 33.6 101.00 12.10 10.56%
BKT Skid Power 12-16.5 32.3 95.4 12.0 4.43%

Formula to calculate lead/lag: front RC / rear RC x drive ratio (1.564) x 100%

Even though the 12-16.5 tires will fit the front factory wheels, I ended up buying new wider front wheels that are standard on the MX series to better fit the new tires. What actually surprised me is that I can now easily shift in and out of 4x4, where previously it often felt like the drivetrain was binding, making it hard to shift, especially out of 4x4. I also noticed a definite improvement in steering ability while pulling hills in snow. This is likely due to the front tires now leading the rears, instead of the rears trying to push the fronts. I love everything about the tractor now. I'm not sure why Kubota can't seem to figure this out. I attached some pics of the tires side by side for comparison, and the new tires installed on the tractor.

 

[greenrider1]

Not sure why my spacing didn't come out right where I listed the tire specs. Here's a side by side pic before they were installed.View attachment 594079

Having trouble with the pics too. Not sure why the one doesn't show up without clicking on the file. I can't seem to get rid of the thumbnail either.

 

[OrangeRidge]

Those front tyres are quite different . It is bad that a manufacturer can't get their act together on this matter . You'd definitely
notice the correct pull from the front end when turning now . So much for what's supposed to be a FWA ( front wheel assist ) tractor from the factory .

 

[moship]

Do the wider tires cause any problems when turned completely one way or the other? IE: Did you have to alter the turning stops?

How did you find the gear ratio? I'd like to find it for my L4740-3 and L3130 both HST.

Thanks for sharing!

 

[FatTire]

Thanks for this report Greenrider1. This is the only remaining issue that I have on my L5740, I'miss the larger fronts that were on my MX5100. I want to do what you've done when my fronts get a little more worn. What is the difference in rim width between the two? Also where did you purchase the BKTs? Locally or internet?

I've posted this photo before, showing the difference:

 

[greenrider1]

The larger tires fit just fine without any modifications. Plenty of room. I lifted the front end with the loader and turned them stop to stop with the axle tilted both ways and all is good. I called two different dealers and neither could find it, so I ended up emailing Kubota directly and received a response within a couple of hours.

 

[greenrider1]

I purchased the BKT's from Simple Tire through ebay. They are 10 ply instead of the factory 6 ply but I don't feel any noticeable difference in ride. From what I recall the factory wheels are 8.25 width and the MX wheels are 9.75 width, so 1.5" difference. Tractor Xchange had the best price on the wheels and shipping was very reasonable.

 

[greenrider1]

It's been a couple years now with the BKT Skid Power front tires and they were well worth the money for the upgrade. My front end floats much better on soft ground, and these tires don't squat like the originals with a heavy load in the bucket. I used to rut the hell out of my yard if I needed to cross it when the ground was soft, but it's much better now. No problems shifting in and out of 4x4. An added plus is they also look much better than the tiny 10-16.5 factory tires.

 

[tsmithco]

What wheels exactly do you have? I've read through this post and it wasn't clear to me.

I've got to replace my front wheel on my L5740 and want to upgrade. (1 is factory and 1 is a Titan HD 2000) so I need to switch them both out - not sure why the previous owner did that!

 

[SDT]

It's been a couple years now with the BKT Skid Power front tires and they were well worth the money for the upgrade. My front end floats much better on soft ground, and these tires don't squat like the originals with a heavy load in the bucket. I used to rut the hell out of my yard if I needed to cross it when the ground was soft, but it's much better now. No problems shifting in and out of 4x4. An added plus is they also look much better than the tiny 10-16.5 factory tires.

Never any problem shifting in/out of FWA with my L6060 and factory R4 tires unless turning which one should not do anyway.