Tires Kubota tire switch

forthemostpart · Dec 30, 2011

The manufacturer listed AG tires for my L3400 HST are 11.2-24(rear) and 7-16 (front). I have a set on rims that are off an L3130 HST and the front are indentical but the rear are 12.4-24. From what I understand the only difference is that the 12.4-24 would be about an inch wider but gear/ratio wise, there would be no problem. Am I correct to assume that all will be good? C,

greenrider1 · Dec 30, 2011

Try going to Firestone Agricultural Tire. Website is easy to use, and it shows different tire sizes and specs. Keep in mind that different brands of tires specs may differ slightly. According to Firestone, the 11.2-24 has around a 43" diameter and 129" rolling circumference (depending on tire model) and the 12.4-24 has an average 45.6" diameter and 135" rolling circumference (again, depending on specific model). This could throw off the front to rear ratio, which I believe should stay within 0-5% front tire lead. Width has no effect on the ratio and won't matter, as long as they will clear your inner fender. You may be able to run the rears a little soft and get away with it.

teg · Dec 30, 2011

I don't have Ag's so I can't help... I guess what you'll need is the rolling circumference of factory R1-Ag's... front and back to see if it matches the ratio.

forthemostpart · Dec 30, 2011

Perhaps another way to determine compatability is if the gear ratio on the L3130 and the L3400 is identical, then what is good for the goose, is good for the gander. Is there anybody out that would know this? C.

forthemostpart · Dec 30, 2011

Allright, now, I think I am making progress....does anyone know what the gear ratio is for the L3400? C.

teg · Dec 30, 2011

Could the ratio be calculated using the rolling circumference of any tire? ...and shouldn't that ratio be the same for all of them???

forthemostpart · Dec 30, 2011

The original tires are Titan/Goodyear. I went on their website and was able to get circumference on them. I then calculated the ratio for both R1s and R4s. One set came to 1.48 and the other 1.49. So that seemed to be rational. The ratio for the set of R1s that I have is 1.57 which is about 5% off the specified Kubota tires. So what I would like to know now is compare 1.57 to the true gear ratio. Does this make any sense? C.