Got a Kubota b1750 4wd and starting down the rabbit hole of getting front tires for it. It’s got 31x15.50-15 Goodyear I think “xtra trac” tires. I’m pretty sure what originally came on it and the annoying 20.5x8.00-10 Bridgestone front tires. I found some tires online I like, but both are 20x8.00-10’s. Carlisle trac chief R4 tread and OTR 22 mag with R1 type tread. I’m trying to read through old posts to understand what I need to do to know if these will work and I’m not totally following all the numbers and math. I really want a R1 style traditional tractor tire for the front if something can be found, but I would settle for the R4 tread if need be. The original Bridgestones aren’t “worn out” on it, but I’m wanting something with more bite and traction for when I have the rear blade on or mowing some of the slicker areas on my property I’ve acquired. Putting it in 4wd now those turf type front tires aren’t giving me much help.
Kubota b1750 front tires help
- Thread starter AndyC15
- Start date
20x8-10 will work fine. Most likely will be a hair taller than your current 20.5 turf tires. You could always swap to the skinny rims and run a 6-12 front and 9.5-16 rear ag tires as well but would require different rims
I really don’t wanna have to swap wheels if I don’t have to. Wheels are still in mint shape and the back tires, while old, still have tons of tread life left and hold air perfectly. Lot of the older threads I’ve been reading have a lot of numbers and math being thrown around to calculate things making sure the 4wd can still be used safely and I’m way lost in it all.
I understand. Yes searching forums you'll think its way more complicated than it is. Basically your ratio between front and rear is 1.53 with a 1-5% lead on the front. So 31÷20.5 is 1.51 and 31÷20 is 1.55 so close enough. But to complicate things further you should technically use the rolling circumference instead of tire diameter as there can be large discrepancies between actual diameter between manufacturers. Plus factoring in wear diameters will change. Most will go through several sets of front tires before needing rear tires. At the end of the day though the true test is the concrete test. Drive on hard surface in 4wd 50 foot or so and move your lever to 2wd. If it moves easily your good. If its binding up youll feel it in the lever when you move it. Test it both in forward and reverse.
tires I’m looking at I don’t have the rolling circumference size, but on the manufacture website they are listed as a 20” tire however they list the OD at 20.5, so maybe they’ll be near identical to what I have and I won’t end up ripping out the front end