Turf to AG on a B8200 HSTD question

Report back what you find. I'll be reading with interest.

I also have a B8200HSD and mine came with ags on the front and diamond tread turfs on the rear. I'm an engineer and it isn't obvious to me how to measure the effective diameter for comparison.

The rears aren't in great shape and I imagine I'll be replacing them at some point. I had one tubed at Les Schwab because it had a slow leak from the weather checked sidewall.

They noticed that the rear wheels are custom made. The seller insisted that these wheels are the same size as with the ags that he removed, but I can't be sure that is true.

How does it drive in 4WD? Any binding, does it feel tight when you are moving, do you have to back it up to get out of 4WD if you have driven straight?

Hey guys, The best damned price I found here in Quebec for the carlisle tires was 789. a piece, and I need new tires and rims (desperately). Cant find any rear rims either. I want some R4's. Any info would be great.

Hopefully your educated guess will work out as it appears to be so far.

As the engineer pointed out he didn't know/wasn't sure how to figure it out.
That was not only a wise statement but practical too and I think I need to get with a moderator ans post a permenant post on how to calculate exactly what everyone MUST know when changing tires on a 4X4 or mechanical front wheel assist tractor.

You can look at diameter and be somewhat close but in reality no cigar.
You need to know the rolling circumference of each tire and use that to figure out what the percentage is. Take the rolling circumference of the front tire and divide that by the rolling circumference of the rear tire. The number you come up with is the RATIO front to rear. Knowing that and knowing what the actualy rolling circumference ( remember too that rim with changes the size of the tire too! ) only then can you figure out what else will work. I've beat this horse to death many times on different tractors and have at times not been able to come up with the correct combination to satisfy someone's needs to change tread designs especially. As always air pressure which can change the size or length of footprint is critical !!! I have been able at times to make up for the difference in size that was close but not close enough to change the outcome by adjusting air pressure.

Not doing your homework correctly is or I should say can be a very expensive mistake if you tear up the gears etc in the front end or worse. It's bad enough expense wise to pay for a new set of tires, but tearing up the tractor and adding another $1500 to $2500 to the bill PLUS another set of correct tires can be EXPENSIVE to say the least.
Nuff said I'll step down off my soap box....
Al

I am in the process of doing this same swap on my B2150 at the moment, local dealer has to order in all the tires, will be getting the same Carlisle Trac chief 12.4-16-on the rears but the front carlisles 24-8.50-12 are on factory back order but they have a couple other options for fronts in the same type tread, Can't remeber what brand they are. The diameter still puts it close to the propper drive ratio one came in at 1.61 and can't remember the other, I told them to get the one closest to 1.66.

The whole set of 4 will be almost the same price as what it would have cost to replace the rear carlisle turfs alone.
I am putting tubes and chloride in the rears at the same time.

Just got the new treads on the rig tonight.

Carlisle Trac Chief I3 6 ply 12.4 X 16 on the rear with tubes and 20 gallons of Chloride in each one.
Approx 220 lbs ballast in each tire plus each tire weighs 80 lbs plus the rim weight gives me about 700 lbs of rear end weight now, should help a lot with my big 68" loader bucket.

Mounted diameter = 37.2"
Rolling circumference = 117"

Fronts are 6 ply bias BKT Skid power HD 23 X 8.50 X 12 "couldn't get carlisle's in this size, factory backrdered"

Mounted diameter = 23.05"
Rolling circumference = 67.95"

Gives me a 1.721 drive ratio.
Now to see how she performs.

Wild and Free said:

Just got the new treads on the rig tonight.

Carlisle Trac Chief I3 6 ply 12.4 X 16 on the rear with tubes and 20 gallons of Chloride in each one.
Approx 220 lbs ballast in each tire plus each tire weighs 80 lbs plus the rim weight gives me about 700 lbs of rear end weight now, should help a lot with my big 68" loader bucket.

Mounted diameter = 37.2"
Rolling circumference = 117"

Fronts are 6 ply bias BKT Skid power HD 23 X 8.50 X 12 "couldn't get carlisle's in this size, factory backrdered"

Mounted diameter = 23.05"
Rolling circumference = 67.95"

Gives me a 1.721 drive ratio.
Now to see how she performs.

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Wild,
I think you're in for some big problems buddy, your math is all wrong and here's why: in order to figure the ratio you divide the front tire rolling circumference by the the rolling circumference of the rear tire. So here's how that works out: 67.95 divided by 117= 58 ratio and it must be within 2% in order not to cause problems.
The rolling circumference of the 12.4-16 Trac Chief is 108.1, and the rolling circumference of the 23x850-12 Trac Chief is 68.9, so now lets do the math:
68.9 divided by 108.1= .637 so we'll round that off to .64
I sure hope you haven't made the purchase and if so hope you haven't used the 4 wheel drive in anything where you could get a decent bite of traction so it won't explode when the parts start breaking!

You need to start over with what was originally on the tractor and get the true rolling circumference based on mfg specs and do that math. It irritates me to no end that many tractor dealers and tire dealers always seem so darn clueless when it comes to 4 wheel drives. I'd bet money you won't find ANY tire retailer that would sell you 2 totally different tires in size front to rear if you drove in there with your every day 4 wheel drive pickup truck because they know that will screw everything up quickly. But, they somehow don't seem to relate that a 4 wheel drive tractor is just as easy to mess up as that pickup truck. I will give some the benefit of doubt since the tractors we're discussing here never have the same size front to rear, but they should at least have a clue and find out what is and isn't proper before they sell you the goods.
Al

tiredguy said:

Wild,
I think you're in for some big problems buddy, your math is all wrong and here's why: in order to figure the ratio you divide the front tire rolling circumference by the the rolling circumference of the rear tire. So here's how that works out: 67.95 divided by 117= 58 ratio and it must be within 2% in order not to cause problems.
The rolling circumference of the 12.4-16 Trac Chief is 108.1, and the rolling circumference of the 23x850-12 Trac Chief is 68.9, so now lets do the math:
68.9 divided by 108.1= .637 so we'll round that off to .64
I sure hope you haven't made the purchase and if so hope you haven't used the 4 wheel drive in anything where you could get a decent bite of traction so it won't explode when the parts start breaking!

You need to start over with what was originally on the tractor and get the true rolling circumference based on mfg specs and do that math. It irritates me to no end that many tractor dealers and tire dealers always seem so darn clueless when it comes to 4 wheel drives. I'd bet money you won't find ANY tire retailer that would sell you 2 totally different tires in size front to rear if you drove in there with your every day 4 wheel drive pickup truck because they know that will screw everything up quickly. But, they somehow don't seem to relate that a 4 wheel drive tractor is just as easy to mess up as that pickup truck. I will give some the benefit of doubt since the tractors we're discussing here never have the same size front to rear, but they should at least have a clue and find out what is and isn't proper before they sell you the goods.
Al

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I appreciate the info but you lost me at where you got the 108.1 and 68.9 numbers from? From your calculations how many percent am I off from the 2% acceptable norm? I stressed that they needed to be within the same range as the originals and they didn't seem concerned at all with the ones they chose for the fronts, if it truely does act up they are a good company and will make it right for me.
Tires are bought and on the tractor as the pics in the post above show.I had the exact same size/brand turf tires as the OP and went with the same rears and just different brand fronts in the same size which are about 1/2 inch bigger than the fronts the OP went with.

From all the info and spec i have the front tires are about 1/2 inch taller than the original turf tires and the rears are the same. Having been a heavy diesel tech for 20+ years and most of that working on 4 wheel drive and FWA ag tractors and 4 wheel drive payloaders and Backhoes among other loaders the chances of finding a loader other than new with matching tread diameters from from to rear are slim to none, Mine will be in the dirt 99% of the time and as long as the fronts are pulling a bit more than the rear I have never seen an issue.

I will get to try it out over the next couple of days as we are supposed to get 8-14 inches of heavy wet snow over the next 36 hours.

Wild and Free said:

I appreciate the info but you lost me at where you got the 108.1 and 68.9 numbers from? From your calculations how many percent am I off from the 2% acceptable norm? I stressed that they needed to be within the same range as the originals and they didn't seem concerned at all with the ones they chose for the fronts, if it truely does act up they are a good company and will make it right for me.
Tires are bought and on the tractor as the pics in the post above show.I had the exact same size/brand turf tires as the OP and went with the same rears and just different brand fronts in the same size which are about 1/2 inch bigger than the fronts the OP went with.

From all the info and spec i have the front tires are about 1/2 inch taller than the original turf tires and the rears are the same. Having been a heavy diesel tech for 20+ years and most of that working on 4 wheel drive and FWA ag tractors and 4 wheel drive payloaders and Backhoes among other loaders the chances of finding a loader other than new with matching tread diameters from from to rear are slim to none, Mine will be in the dirt 99% of the time and as long as the fronts are pulling a bit more than the rear I have never seen an issue.

I will get to try it out over the next couple of days as we are supposed to get 8-14 inches of heavy wet snow over the next 36 hours.

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Wild,
where I got hose numbers is from the specs Carlisle has published in their catalog on farm tires plus I used what specs you already had listed that way when you wrote the sizes down diameter and rolling circumference.
Let me make this clear for eveyone:

ROLLING CIRCUMFERENCE ARE THE "MAGIC NUMBERS" YOU NEED TO FIGURE OUT WHAT THE ORIGINAL RATIO WAS AND THE NUMBERS YOU NEED TO USE IN ORDER TO GET THE REPLACEMENTS TO MAINTAIN THE CORRECT GEAR RATIO FRONT TO REAR PERIOD.

All I'm saying Wild is that it appears that you are off far enough to cause a problem with binding which will lead to premature wear of the drive line parts or worse, major breakage such as the ring and pinions etc. You're experienced with working on front end loaders and probably know each brand varies in actual size from one to another, and know they must all be as close as possible or it can cause problems. You wouldn't dream of mixing them up with say 20.5-25's on one end and 23.5-25's on the other right? That's because just like a normal passenger or light truck 4 wheel drive vehicle they're set up to all be the same.
Tractors that are 4 wheel drive we own and deal with on this forum are actually "mechanical front wheel assist" and don't come with the same size tires front and rear, so to compensate for the different size tires usually the ring and pinions in the front and rear are different ratio's and that where the compensation is changed/altered to make up the difference with the tire sizes themselves. MFWD (mechanical front wheel drive ) on tractors is set up so that the front end is slightly faster than the rear so that it is always pulling you forward which is what makes them so awesome to have. If the rear spins faster than the front pulls it will bind, if the front pulls to much faster than the rear it will bind. Where it binds is where it breaks parts if to much torque manages to be applied hard enough and long enough to breal the weakest link. If your moving snow and it's slippery as usual you usually don't get enough traction same as you don't in mud or wet clay to get a solid enough bite. But, if you were pulling something where the torque was high up a hill on dry concrete or asphalt that load definitely is where all hell breaks loose. The weakest link in the chain is always where it breaks first.

You had written: The diameter still puts it close to the propper drive ratio one came in at 1.61 and can't remember the other, I told them to get the one closest to 1.66.
The difference between those numbers is 7% alone IF they were actually correct which I pointed out they weren't. I figured them correctly which is a difference of 9% in reality and both numbers even if I were wrong is WAY over the 2% allowance.
So all I did was use the numbers you had shown to discover there was an error. You were trying to get as close to 66 and now you think you have 72 and if that's really where you're at now you are at 8% diffence totally unacceptable since 2% is all that's allowed.
Al

Thanks Al, Time will tell now,

But your spec book and the info I printed off their sites differ, I have the sheets I printed directly off each tire mfg web sites which is the info I posted above and they seem to differ from the books you have.

Thank you for going the extra mile on this subject.

I sent you a couple e-mails with my info.

Bill.

The actual gear ratio in th B8200 is 1.691 It is best to use it in your calculations!

I have a B8200 with 24X8.5-12 front tires. Need new tires, but can find only 23X8.5-12 as replacements-- can I use them without having a problem? The rear tires are 13.6-16. Thanks for any help. Don't want to screw-up my toy.

ibigjon said:

I have a B8200 with 24X8.5-12 front tires. Need new tires, but can find only 23X8.5-12 as replacements-- can I use them without having a problem? The rear tires are 13.6-16. Thanks for any help. Don't want to screw-up my toy.

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Look up the actual rolling circumference of the tires.......don't go by tire size.

eserv said:

The actual gear ratio in th B8200 is 1.691 It is best to use it in your calculations!

Click to expand...

Eserv,
your information always seems to be on the money and I know you've got the inside track on getting information, so could you tell me how you got that 69 ratio please? I'm no expert and am trying to gather as much information as I can to be able to help here and in my business too. I've been keeping notes on the different combinations and trying to get the model numbers too so that I can refer to my notes instead of going to the tire books and websites
to find what I need. I pay special attention when I see you jump in buddy, as I've learned quite a bit from what you bring to the table all across the different problems in all areas.

I just had a situation come up where I was dealing with my Kubota dealer as a customer ( I'm a tire distributor ) who had a customer wanting to change from R1 to Turf and figured out what would work which he quoted him on.His customer had put an ad on Craigslist hoping to find a buyer so he could afford the change easier etc. He got a bite on his ad and struck up a deal and they were going to swap tires and wheels, and met with their tractors at a tire dealer in the area to make the deal. I got a call from the tire dealer asking me a bunch of questions as the wheel offset was wasn't quite the same on the rear and I just smelled a rat, so I ask him for the model numbers and BINGO! it was the same deal I'd just worked on figuring out. The tire combos they had were totally wrong and by luck we figured out what was going on in time to save them both from a possible catastrophe.
Al

lsmurphy said:

Look up the actual rolling circumference of the tires.......don't go by tire size.

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how close to the spec. ratio of 1.691 must it be?