Tire help

   / Tire help #1  

bikerdib

Platinum Member
Joined
May 29, 2010
Messages
693
Location
Texas
Tractor
Kubota L4701
Tire help ~ yes I'm bringing it up again

My B7300 has turf tires; front 21x8-10, rear 31x15.5-15.

I'm sure those of you with the same size tires have come against the same problem as I; finding tires that will work.

The rear on my machine are not too bad but my front are pretty dry rotted. I went to Firestone's website and found that the TL G-2 is discontinued. I'm looking for solutions (like many others). I know about the trailer tire option but I want more traction. The 21x8 actually has a mounted diameter of 20.5 and I read on another forum that someone has used a Carlisle All Trail in 20x10-10 which is supposed to have a mounted diameter of 20.1; I'm just not sure if that is a good option.

Of course I have the expensive option of switching out the wheels to the 6x12 front and 8.3x16 rear but I'm afraid that tires for those rims might become hard to find also. Can someone give me the tire sizes for those rims. I wouldn't mind having ag type tires anyway.
 
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   / Tire help #2  
Try Ken Jones Tire @ KenJones.com. May not have what your looking for, but maybe they know where to get it, or to refer you to?
 
   / Tire help #3  
Say, Bikerdib look at grandv8's post today 10/4 title'd: to those looking for 20.5 x 8-10 tires. Looks like he might have a solution for you to with Carlisle for your sizes. Click on his links.
 
   / Tire help
  • Thread Starter
#4  
Thanks for the tip. However, I already knew about the All Trail from Carlisle; in fact I now have some on order through my cousin's auto mechanic shop (should be in today). I think the All Trail should work. I'll know later today after I get them mounted (I have a tire changer in my shop because I do most of my own motorcycle maintenance).
 
   / Tire help #5  
Are you mounting the 20x10-10's on the original (21x8-10) rims?

also, do you mind saying how much the 20x10-10's cost ?

thanks...
 
   / Tire help
  • Thread Starter
#6  
Yes, I'm using the original rims. On Carlisle's web site they say the 20X10-10 are designed to mount on a 6X10 rim, which is the stock size on my B7300 (and I think the B7100 used the same rim size but different bolt pattern). The 21X8-10 Firestone Turf & Field were actually 20.5 mounted (my measurement). The Carlisle are supposed to be 20.1 mounted. I'll post the actual measurement I get after I mount them this afternoon. I also plan on measuring the ground to rim height of both the old and new tires when the tractor weight is on the tires (this will be the most critical check).

Here is a link to their website:

http://www.carlisletire.com/products/atv/all_trail/index.html
 
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   / Tire help #7  
Thanks...

I have a 1995 B1700 with 21x 8.00 -10 front and 31x 15.5 -15 rear...these are the original (industrial) tread tires....
...after an exhuastive search last year I found that that size (front) tire is simply N/A...because the trctor is 4x4 I was told that is paramount to maintain the same ratio of "rolling circumferences" to prevent damage...

I have still been unable to find any tire that would maintain the (exact) same ratio without changing out the rear tires which means changing out all 4 rims...

comments?
 
   / Tire help
  • Thread Starter
#8  
Just got the Carlisle All Trail 20X10-10 tires mounted so I thought I'd give a report.

Before taking the wheels off the B7300, I checked the air pressure (because of my FEL I normally run 25 psi). I measured the static load radius of the Firestone Field & Turf that were on my tractor. This measurement is the ground to center of axle distance with the weight of the tractor being supported by the tire. It was hard to measure from the concrete to the exact center of the axle so instead I measured from the concrete to the bottom lip of the rim but this will give the same effective check since I was only concerned with the difference between the old and new tires. With the Firestone, this measurement was 4 & 1/16 inches on one side and 4 inches on the other (difference in wear?). After removing the wheel, I measured the outermost mounted diameter of the tire with no weight and found it to be 20 & 9/16 inch (so like others have said, the 21X8-10 is actually still a 20.5X8-10). For our needs I think the static load radius is the most crucial.

I dis-mounted the Firestones and mounted the Carlisle. Aired the tires up and measured the outermost diameter of the Carlisle. It measured 20 & 3/16. I got worried, maybe this was going to be too small a tire after all. I put the wheels on the tractor and measured the static load radius. I got 3 & 15/16 inches, a loss of only 1/8 to 3/16 of an inch (allowing for measurement errors). That should work, at least for me since I only use 4X4 on low traction surfaces. I think uneven tire inflation and tread wear can cause a bigger differences than I'm getting between the old and new tires.

The Carlisle have almost 200 lbs more carrying capacity than the Firestone so I think that might account for the reduction in sidewall flex so the Carlisle might be even better when hauling a load in the FEL. This should mean even less of a difference in size between the loaded Firestone and the loaded Carlisle.

BTW, I tried the test of putting the tractor in 4X4 and the trany in neutral then pushing the tractor. I couldn't tell much of a difference between the old and new tires but this test if not very accurate because I had no way of measuring the amount of force needed to move the tractor.
 
   / Tire help
  • Thread Starter
#9  
Slash Pine, apparently you posted while I was typing. As you can see from my post above, the Carlisle is slightly different. So, if you use 4X4 on pavement you might have a problem but if you only use 4X4 on low traction surfaces (like me) I think they should be OK. In fact, I VERY seldom drive my tractor on pavement even in 2X4.

I went through the same dilemma, change all four to the ag type tires and wheels or experiment with the Carlisle. I prefer the wider footprint the turf type tires give so I decided to experiment. I hope I made the right choice, only some seat time will tell.
 
   / Tire help #10  
Just got the Carlisle All Trail 20X10-10 tires mounted so I thought I'd give a report.

did you measure the rolling circumferences of the old and the new tires ?
 
 
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