B1700 Front tires?

[vmaxx4]

Hi Guys

I am need of replacement tires for my B1700. The original tire size was 21 X 8 X 10 - Field and Turf - Firestones. I have been told that these were specifically made for Kubota by Firestone and are not available through a Firestone dealer. Kubota Canada has these tires in stock but wants over $300 each. Does anyone know of any other tire options? I need to keep the correct tire size due to the 4 X 4 ratio.

Thanks.

 

[magicheater]

Just do a google search for the size and type of tire you want. Read the specs, especially the "static loaded radius" or the diameter and match to the specs of the tire you have. I like to get within 2-3% for safety sakes and have done this on two Kubotas with success. I had to change the rim size to get the type of tire I wanted for my B7800 but managed to find what I wanted after months of asking tire dealers and researching. Your problem should be much easier. Good luck.

 

[stylo]

hey guys glad im not alone with this problem. vic i have a b7100 hst 4wd that also needs front tires. they are 20.5x8-10. now i can get them no problem but the problem is there like a golf cart tire with no tread. so a tractor repair place down the road told me he had a set of 20x8-10s turf tires, witch is what i want, would this be ok to use? i dont want to screw up the 4wd or the tranny.

 

[stylo]

cool thanks again vic!! your knowledge is greatly apprected!!!!

 

[bikerdib]

After much research looking for a replacement for the Firestone Field & Turf 21X8-10 front tires on my B7300 (no longer made), I found I had 3 viable options. Buy the new rims and tires from the dealer to switch to ag type tires, or buy the direct replacement for the 21X8-10 from the dealer ($$$$$$$$$$), or try to find a tire that is close in size. Since I'm kinda a penny pincher and since I operate mostly on sandy soil I also like the larger footprint of the turf style tires; I decided to try to find a close size.

From the Firestone website I found the 21X8-10 turf tire is supposed to have a mounted diameter of 20.5 inches.

My research led me to 2 different tires from Carlisle, either a turf in 20X10-10 with a mounted diameter of 20.8 inches but with very short and closely spaced lugs so very little traction:

product 511116
http://www.carlisletire.com/products/turf_handlers/turf_saver/index.html

or what is supposed to be a UTV tire in 20X10-10 that has an outside diameter of 20.1 inches:

product 511045
http://www.carlisletire.com/products/atv/all_trail/index.html

I wanted the extra traction so I went with the UTV tire, the Carlisle All Trail.

I mounted the tires myself so before I removed the Firestones, I measured from the concrete to the bottom lip of the wheel rim with the weight of the tractor on the tire: 4 inches one tire, 4 & 1/16 inches on the other (with 24 psi in the tires for FEL work). This would give me an effective measurement of the static load radius. I dis-mounted the Firestones and mounted the All Trails, aired them to 24 psi (sidewall say 22 psi so go over at your own risk), put them on the tractor and again measured from the concrete to bottom lip of the wheel rim. Found 3 & 15/16 inches; close enough IMO. I only use 4X4 on low traction surfaces so I don't think I'll do any damage to the drive train (at least I hope not).

The All Trails are rated to haul 1160 lbs while the Firestones are rated for 975. I think the Firestone had more sidewall flex than the Carlisle and that's why there is so little difference in measured height. If I'm doing my math correctly, that will give a rolling circumference difference of around 0.3 or 0.4 inches between the Carlisle and the Firestone. Plus, since the Carlisle seem to hold up a load better, I'll probably be even closer when hauling something in the FEL when compared to the Firestone.

 

[tiredguy]

Sorry you're living the dream/nightmare of having not only current,but actually the 2nd generation of discontinued tires from Bridgestone-Firestone.

Here's the ONLY thing you need to know about replacing them with the proper size so you don't screw up your front end or transfer case:
ROLLING CIRCUMFERANCE!!! The only way to determine rolling circumferance if the manufacturer of the tire doesn't have it,is to mount a tire put it on the tractor and measure the distance of travel under a normal load.PERIOD! Nothing else that you read regardless of what the specifications shows means
anything other than the "Magic Number" which is: "ROLLING CIRCUMFERANCE".

I'm in the business and have spent many hours searching and trying physically many types of tires to no avail.I did however come up with only one solution which isn't the best but absolutely will not cause you any problems at all size wise,which is this: 20.5x8-10 Carlisle USA Trail in load range C (6 ply) and aired up to 35psi. No other brand or ply or air pressure I've tried will work so far. You need 61 inches of rolling circumference and this set up will give you just under 61.25 which is well within tolerance not to cause a bind or over speed. It's not good for traction,but could be "grooved" with a truck tire cutter to give you more.Another thing for ice if you have a place that can do tires this small would be to have them tractionized (micro siped cuts accross the tread face) which is better than any turf tire for traction on ice.

If anyone finds through there trial and error a tire meeting the 31 inches rolling circumferance please let me know so I can save others (and myself) a whole bunch of greif and aggravation.

 

[tiredguy]

Biker,
I should have ask you to measure your rolling circumference because memory tells me what you're running now isn't right and could cause pexpensive problems.

To measure rolling circumferencen a level and smooth surface like driveway or garage/shop floor,mark the tire being measured at the bottom center of the sidewall where it meets the surface along with the surface itself.Have someone observe and drive the tractor until the tire mark rolls around to exactly the same position it was when you started making one complete revolution.Then measure the distance between those two points and that
"Magic Number" is your "Rolling Circumference".
Air pressure can and will change the size of a tire,so sometimes a minor ajustment in that as long as your do not over inflate the tire will help get you where you need to be.

I'm a wholesale tire distributor serving all of the northern lower portion of Michigan and part of the upper peninsula dealing with hundreds of dealers.
The B7100 is an awesome tractor and many have been sold here and will last a couple of lifetimes if taken care of service and operation wise.Of course the tires won't live as long as the other parts will,so they'll need to be replaced every so many years or if ruined running over something.This is only one of several tractors in various brands models and sizes that tires are no longer made in the original or close enough in tolerance to work unfortunately.

 

[bikerdib]

Tireguy, funny you came along and posted this because a few days ago I posted this on another forum.

I finally got a little free time so I decided to go through the trouble of measuring the ACTUAL rolling circumference of the Carlisle All Trail vs the Firestone Turf & Field. Luckily, I mount my own tires using a manual tire changer so I was able to do this experiment at no cost other than a sore back (hey, I'm 54 years old, cut me some slack) and some time.

First I checked the air pressure in the Carlisle I had already mounted. 28 psi is where I run these tires on the tractor. Used a level to put a mark at the top and bottom of the tire (vertically level) then a mark on the concrete at the bottom of the level. Rolled the tractor forward till the marks went one full revolution and came to vertically level again, then put a mark on the concrete. Measured the distance between marks (which is of course the rolling circumference). The Carlisle have a loaded (please note I have a FEL installed) rolling circumference of 60 inches.

I removed one of the wheels, dis-mounted the Carlisle, mounted the old OEM Firestone I had recently taken off. Put the wheel back on the tractor with 25 psi in the tire. Used the level to duplicate the way I made the marks again. Measured between the marks and found out the Firestones have a loaded rolling circumference of 62 inches.

Now I'm a little surprised at the Firestones because the Firestone website specifies a rolling circumference of 61 inches. This means we can't even go by the info provided by the tire manufacturer.

Now I have to eat my words because I decided that was too much difference. I took the other Carlisle off and I'm back to running the dry rotted Firestones for now. Looks like I may be back to square one of getting all four wheels and tires replaced with R1s. This doesn't really bother me too much because I could use the extra traction anyway. But for those of you that need turfs, I can't recommend the Carlisle All Trail like I originally thought (unless you never use 4X4).

 

[SpudHauler]

It would be interesting to know what 20lbs air would give you in circumference.

 

[bikerdib]

I've discussed that at length on another forum. Changing your air pressure will change the static load radius thereby changing slightly the rolling circumference. I have to keep my tires aired up because of the FEL. Sidewall flex must be kept to a minimum.

 

[SpudHauler]

I've discussed that at length on another forum. Changing your air pressure will change the static load radius thereby changing slightly the rolling circumference. I have to keep my tires aired up because of the FEL. Sidewall flex must be kept to a minimum.

Right on! I'll take a look, but for now see what you mean. Thanks!

 

[bikerdib]

I decided to go to my dealer to find out what it would cost to switch over to R1 tires. This would of course require replacing all four wheels and tires. I'd like the extra traction anyway I just hate the cost it will involve.

My dealer has a set of the front wheels with 6X12 R1 tires in stock, this is the OEM stock size on a B7300 for R1s. He will sell me both for $175. Great, I have the front solved at a great price. BUT, he only had one of the rear 8.3X16 wheel & tire (the OEM stock match to the 6X12 fronts). He did have an older set of 16 inch wheels with worn out tires. He said he'd sell me the old wheels for $100 for both and I would just have to get new tires for those wheels. Now I'm thinking "I've got this licked."

Well guess what; we called around and there is no aftermarket supplier that has the 8.3x16 available.

Now this has driven the cost of switching over to R1s to around $800 because now I'll have to get the 8.3X16 through his Kubota only vendor and we all know how pricey that can be.

There still might be another option we are looking into. The L4400 uses a 8.3X16 as a front tire. This is a 6 lug bolt with the same spacing as my B7300. We might try ordering the wheels & tires and see if they will bolt on my B7300 as rears. With shipping and tax (and the 2 6X12s he has in stock) that would run me between $675 and $700 total.