Yet another wheel and tire thread…..

PNW-Redleg

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Equipment
1978 B7100
Jul 3, 2022
25
8
3
Utopia of Portlandia
Don't know your location, buy miller tire had very good prices when I got tires for my B. The only downside is I got Carlisle for the rear and had to get galaxy for the front due to not being able to get the right size in Carlisle brand. More or less same tread pattern so it didn't really matter. Cheers on yoir new tires can go wrong with a std r1 pattern, you know exactly what to expect with them.
Tires shipped 2 you had all 4 Carlisle farm specialist in stock, for $450 shipped. They’ll be here Sunday or Monday.

Hey, R1s are the standard for a reason. Yeah they won't be ideal on pavement but it's also unlikely you're going to be pushing on anything hard enough on pavement to spin 4 tires. Usually all the stuff you need maximum traction for is dirt related. I think having 2 sets of tires is a good option. Now being on pavement means a lot less margin for error in the size relationship between front and rear tires for the 4wd system. I would totally avoid using 4wd on pavement unless you start spinning, then put it in 4wd, get that little bit of travel done, and shift it back out of 4wd before continuing. We can only get away with the imperfect relationship between front and rear tire sizes because dirt allows enough slip to make it ok. Pavement will put serious stresses into the system if the front/rear ratio isn't spot on.
On pavement taking dirt to my neighbors place, I keep it in 2. Actually keep it in 2 anytime I’m not digging.

as far as scooping gravel when I need to do that, 4wd won’t hurt for a few feet of driving at the pile in a straight line.
 
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Bugzilla46310

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2022 BX2680 198? AC 916H
May 22, 2022
101
84
28
Demotte, IN
If you want to keep your expense down and the tires hold air and get the job done, I’d do nothing or like previously mentioned, rattle can paint and some tire black.
 

Vigo

Active member

Equipment
B6100, B8200
Jan 9, 2022
318
136
43
San Antonio Texas
On pavement taking dirt to my neighbors place, I keep it in 2. Actually keep it in 2 anytime I’m not digging.

as far as scooping gravel when I need to do that, 4wd won’t hurt for a few feet of driving at the pile in a straight line.
(y) (y)(y) A lot of times I read things that give me sympathy pains for other peoples' machines but sounds like you know what you're doing! The 4wd stuff (ratios, binds, when to and not to use it etc) takes a lot of explaining and you don't need it!

I think sometimes these tiny tractors end up being people's first machines and subject to the operator's 'learning curve' (ouch). I also think new owners are where a lot of the dismissive talk about them being toys etc comes from. If you're running all the levers and pedals correctly you can get a lot of power/work out of these things.
 
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PNW-Redleg

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1978 B7100
Jul 3, 2022
25
8
3
Utopia of Portlandia
(y) (y)(y) A lot of times I read things that give me sympathy pains for other peoples' machines but sounds like you know what you're doing! The 4wd stuff (ratios, binds, when to and not to use it etc) takes a lot of explaining and you don't need it!

I think sometimes these tiny tractors end up being people's first machines and subject to the operator's 'learning curve' (ouch). I also think new owners are where a lot of the dismissive talk about them being toys etc comes from. If you're running all the levers and pedals correctly you can get a lot of power/work out of these things.
Well, This is my first tractor, but not my first time operating one. (Uncle had some old Deere Model A, B, M 80's Diesel, and a couple others. No safety equipment except the orange triangle.)

I can definitely tell it was a couple peoples first tractor before me tho. There's some worn/neglected parts. (Need to figure out tie rod and drag link bar ends).
 
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Vigo

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Equipment
B6100, B8200
Jan 9, 2022
318
136
43
San Antonio Texas
I get you. My B6100 was my first tractor but I have driven some tractors and operated skid steers and excavators before, and i feel that 'machine operator' is basically a subheading under mechanic anyway (Im an ASE master tech and teach automotive at a college). Not that it's not its own profession and plenty of full-time operators wouldn't blow me out of the water, but as a mechanic you learn to feel out the operation of every machine you ever fix and most other types of machines get picked up easily once you know a little bit about how everything mechanically works. If someone didn't know anything about 4wd in general it would be tough to understand when or why you shouldn't be using 4wd, but if you're familiar with 4wd on trucks or jeeps etc then you're already 80% of the way to understanding it on a tractor, except a tractor has different size front and rear tires, so the whole 4wd thing is a good example of 'making the jump' to tractors easily if you have some background mechanical knowledge from something else.

I have not looked into the rod ends. I will say, unironically, that when working on riding mowers and other smaller machinery I have found it is extremely cheap to weld rod ends from automotive swaybar endlinks (smaller than a car tie rod, but same type of thing and dirt cheap) in place of a junky worn out rod end. Although, i would only resort to that on my Kubotas if the rod ends themselves weren't available separately from the whole tie rod assembly or drag link assembly etc. I havent looked.
 

PNW-Redleg

New member

Equipment
1978 B7100
Jul 3, 2022
25
8
3
Utopia of Portlandia
New tires came in today! I sure hope they only look tall/skinny because they’re new and not stretched on the rim yet lol.

3B864D87-2736-481F-8148-46ED79072579.jpeg


wheels were in REALLY rough shape so I hit them with a wire wheel, and patched the valve stem hole to re-drill.Hit them with a rust converter, and tomorrow I will start painting them. Honestly, probably should have done electrolasis.
DA557F57-5BD9-4CFC-BF6A-30EC12AC8848.jpeg

8702F006-1E5F-47B2-B9B9-17564B268171.jpeg


Im going to do a dry pressure test for a few days before filling the tires with WW fluid.
 

woodman55

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Equipment
L6060HSTC, RTV 1100
May 15, 2022
341
189
43
canada
New tires came in today! I sure hope they only look tall/skinny because they’re new and not stretched on the rim yet lol.

View attachment 83382

wheels were in REALLY rough shape so I hit them with a wire wheel, and patched the valve stem hole to re-drill.Hit them with a rust converter, and tomorrow I will start painting them. Honestly, probably should have done electrolasis.
View attachment 83383
View attachment 83384

Im going to do a dry pressure test for a few days before filling the tires with WW fluid.
A bit of info in case you need to do another rim. We used 5/8 flat washers to repair valve stem holes. We also used to bronzed them in. Less heat on thin metal, plus we would put in extra bronze to smooth/fill in the corners and edges. When using the torch we would heat and bent the washer a bit to get it to conform to the shape of the rim a bit better.
 
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Vigo

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Equipment
B6100, B8200
Jan 9, 2022
318
136
43
San Antonio Texas
Ouch on those wheels!

Me being lazy and a little odd, since I have access to brake lathes at the school i teach at, whenever I have ugly wheels I chuck them on a brake lathe and just hold an angle grinder with wire wheel against them as they're spinning to get the first ~80% of the junk off. I HAVE cut on a smaller front wheel on a brake lathe but i sure wouldn't do it on a 16".. too much rpm, toolholder won't go out that far etc etc. But, if you did something like body filler into that nasty surface (once clean), spinning the wheel while going at the bead area with something like a not-too-coarse flap disc should knock down the filler to the level of the metal without changing the metal itself noticeably. I've used real bead sealer, anaerobic gasket maker, and regular rubber cement as bead sealers before.

I've done a lot of electrolysis.. works great but i suspect you'll be left with a rough surface and more work left to do afterwards anyway. I think the real question is, should you just take the easy way out and put a tube in it?
 

PNW-Redleg

New member

Equipment
1978 B7100
Jul 3, 2022
25
8
3
Utopia of Portlandia
Ok. The rage continues. Tires are straight up too skinny and now I can’t return them because they’ve been mounted. 🤬🤬🤬🤬🤬

On top of that, the one rim I finished is leaking, so now I get to re-break it and try to find tubes.
So much for getting anything done this weekend. 🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬🤬
 

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PNW-Redleg

New member

Equipment
1978 B7100
Jul 3, 2022
25
8
3
Utopia of Portlandia
Double posted with my other thread... Probably a no-no, but oh well...



Ok, Been doing a bunch more reading.

My rear R1 WHEELS are 16x8, and had 8-16's on them before.

My NEW R1 Tires are Carlisle Farm Specialist 8-16. Didn't know this before, but the specs sheet online specifies a 6 inch wheel. It also specifies a Section width of 8.3" (My measurement says 6.5")

So, IF the B7100 front-rear ratio is 1.464, requiring a 0-5% lead... (Lets assume all Carlisle Farm Specialist tires here)

Using This Formula quoted below, and the manufacturer numbers here: https://www.carlislebrandtires.com/our-products/product-detail/farm-specialist-r1/

Rear - 29 x 12.50 x 15 (RC = 88 inch @ 15psi) Carlisle TRU POWER
Front - 20 x 8 x 10 (RC = 62 inch @ 25psi) Kenda K378


62 x 1.464 = 90.768 divided by 88 = 1.0314 minus 1 x 100 = 3.14 %

well within the 0-5% lead reccomended by Kubota
I come up with these numbers. Highlighted in green are the tires I ordered, based on other recommendations on this site.

But even the older part number 8-16 looks to have a 7.2% lead, while the newer 6X part number has a nearly 10% lead!

But if I get the 9.5-16 (meant for 8" wide rims) that has a 2.4% lead.

If all of the equations are correct in the quoted post above, AND the 1.4664 ratio is correct.

Screen Shot 2022-07-15 at 10.47.13 PM.png


Even 98.5/68.9 = 1.4296 (Very close to 1.4664)
And 92/68.9 = 1.3353 (Not close to 1.4664)

Does this sound correct?
 

Vigo

Active member

Equipment
B6100, B8200
Jan 9, 2022
318
136
43
San Antonio Texas
I deeply respect the willingness to dive into the math on this because it does work on so many things, but my opinion on this particular subject is that individual tractor tire brand/models vary SO MUCH from their stated specs, that it is nearly a crapshoot and being technically correct with the math might not make it work in real life because what you'll be sent might be different from what they list on the specs.

Tractor tires have a lot of wiggle room on tire pressure. That allows you to vary the 'loaded radius' quite a bit on some tires. Combine that with the forgivingness of loose surfaces and 'good enough is good enough'. I do think the 9.5-16s could potentially work well enough, but pictures ive come across of 9.5-16s and 8-16s on the same tractor (Cases like my 446) made me think they really did have a different diameter, though. Enough to make me a little worried.

And as far as the tubes.. I guess I neglected to mention in my last comment about tubes, that one of the great unsung advantages of tubes is they will spread the tires for you and make it effortless to 'seat the beads' when mounting a tire. As an auto mechanic and teacher of tire machines, I've run into this problem many times on car tires and used various tricks to deal with it, but I suspect on tractor tires the issue is more severe and comes up more of the time. I've seen a LOT of negative reviews of tractor tires online that basically amounted to "tires were kinda smushed from being stacked so i couldn't get the beads to spread out to the wheel" and while i agree that's inconvenient, it's a semi-universal issue of storing and shipping tractor tires, not manufacturing issue, and it' vaguely unfair to have so many negative reviews of sellers over it. But yeah, with a tube you just inflate it and it pushes the tire out for you. Almost worth the price of admission for that feature alone.
 
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PNW-Redleg

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Equipment
1978 B7100
Jul 3, 2022
25
8
3
Utopia of Portlandia
I deeply respect the willingness to dive into the math on this because it does work on so many things, but my opinion on this particular subject is that individual tractor tire brand/models vary SO MUCH from their stated specs, that it is nearly a crapshoot and being technically correct with the math might not make it work in real life because what you'll be sent might be different from what they list on the specs.

Tractor tires have a lot of wiggle room on tire pressure. That allows you to vary the 'loaded radius' quite a bit on some tires. Combine that with the forgivingness of loose surfaces and 'good enough is good enough'. I do think the 9.5-16s could potentially work well enough, but pictures ive come across of 9.5-16s and 8-16s on the same tractor (Cases like my 446) made me think they really did have a different diameter, though. Enough to make me a little worried.

And as far as the tubes.. I guess I neglected to mention in my last comment about tubes, that one of the great unsung advantages of tubes is they will spread the tires for you and make it effortless to 'seat the beads' when mounting a tire. As an auto mechanic and teacher of tire machines, I've run into this problem many times on car tires and used various tricks to deal with it, but I suspect on tractor tires the issue is more severe and comes up more of the time. I've seen a LOT of negative reviews of tractor tires online that basically amounted to "tires were kinda smushed from being stacked so i couldn't get the beads to spread out to the wheel" and while i agree that's inconvenient, it's a semi-universal issue of storing and shipping tractor tires, not manufacturing issue, and it' vaguely unfair to have so many negative reviews of sellers over it. But yeah, with a tube you just inflate it and it pushes the tire out for you. Almost worth the price of admission for that feature alone.
im aware of “smushed from stacked” vs designed a certain way. The new 8-16 Tires are definitely designed for 6” rims.

found the OEM tire specs, and looked them up, did math, and it came out to about 5% lead on the front. What crazy is I probably had a 15% lead with the old rears and newer fronts 🤣

we’ll see how well the math plays out. I’ll measure and verify before mounting.
Tubes are on the way too.
 

Vigo

Active member

Equipment
B6100, B8200
Jan 9, 2022
318
136
43
San Antonio Texas
Nice!

I'm also sort of surprised you have 8" wide wheels in the first place. I don't know all the wheels these things could have come with but anecdotally ive had 2 6100s and 2 7100s here that i've worked on and the ones that had 16s" looked more like 6-6.5" rims, whereas the 16s on my case are definitely 8". I just assumed all the factory kubota 16s on these tractors were narrow.

The 16s i put the 285/75/16s on definitely looked around 6" wide. Luckily I have access to a tire machine that pushes on the tire for you, so cramming tires where they're not supposed to go is not the physical struggle it would be with an older machine.

By far the sketchiest one i've done so far was stuffing some 165/50-15s onto some ~3" wide front wheels for my Kubota L210!
IMG_8820.jpg

IMG_8819.jpg
 
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PNW-Redleg

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Equipment
1978 B7100
Jul 3, 2022
25
8
3
Utopia of Portlandia
Ok, my Carlisle Farm Specialist 9.5-16's came in!

Part Number 6x17413
Pairing with the original 6-12's I ordered (570030)

In the red "test rear" block is the off-rim MEASURED circumfrerence around the center of the tire,
In the red "test front" block is the listed rolling circumference. (I measured it off rim and it was just over 69")

So using the listed RC for the front and the off-rim measured circumference for the rear should give me the largest distance possible, and it's still got a front lead to it. (albeit, slight).

Going to mount these tires up and get them on the tractor now that I've confirmed this. Will report back.

Screen Shot 2022-07-23 at 6.54.05 AM.png
 

PNW-Redleg

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Equipment
1978 B7100
Jul 3, 2022
25
8
3
Utopia of Portlandia
Well the 9.5-16 worked!!!! Just drove it up and down the street in 4x4 and no binding at all. Very easy to put it in and out of 4x4 at all times

LOOK AT THE TIRE DIFFERENCE! And the math worked out too, so I’m happy to see that it really did work.
6-12, 6-12, 8-16, 8-16, 9.5-16 on rim

47C84BCA-B925-4491-811E-00B662C39F92.jpeg


89B4E2A5-3F71-40DF-A024-D693B27A3B5B.jpeg
 
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Vigo

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Equipment
B6100, B8200
Jan 9, 2022
318
136
43
San Antonio Texas
Nice!!

Have you measured the 'loaded radius' ie distance from axle centerline to ground under the tractors full weight? That is the 'dynamic' number the tractor actually sees, and the difference between the static diameter (and radius) and the loaded radius is the wiggle room that i suspect allows us to run slightly 'too big' tires, albeit possibly requiring the use of a fairly low pressure.

Either way, this is encouraging for me since i am planning to swap from 29x12.50-15 to 31x15.5-15, or perhaps 31x13.50-15. I honestly dont see a need to run much over 5-10 psi with tubes filled with liquid.
 

PNW-Redleg

New member

Equipment
1978 B7100
Jul 3, 2022
25
8
3
Utopia of Portlandia
Nice!!

Have you measured the 'loaded radius' ie distance from axle centerline to ground under the tractors full weight? That is the 'dynamic' number the tractor actually sees, and the difference between the static diameter (and radius) and the loaded radius is the wiggle room that i suspect allows us to run slightly 'too big' tires, albeit possibly requiring the use of a fairly low pressure.

Either way, this is encouraging for me since i am planning to swap from 29x12.50-15 to 31x15.5-15, or perhaps 31x13.50-15. I honestly dont see a need to run much over 5-10 psi with tubes filled with liquid.
no, but the off-rim circumference was so close to perfect, and only 2” longer than the advertised RC, so I just rolled with it. Holding the off-rim and mounted tire side by side off the tractor, there was about a .5” difference in diameter.

either way, no binding in 4x4 whatsoever. Even when I’ve forgotten to disengage it driving around on asphalt a couple times.
 
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Raha2341

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Equipment
L2600DT & B2400
Mar 31, 2016
7
0
1
Aberdeen, Oh
I hate to jump in at the end of this for a tire question, but it’s right in line with what you guys are talking about. I got a B1750D with that weird “V” tread pattern on the rears in a 31x15.5-15NHS, but it appears to be a common tire used on Kubotas. I have turf 20.5x8-10 on the fronts, that I need to put aggressive tires on because of hills and mud. R-4’s are useless in these conditions (from experience, and R-1’s are pretty darn good). Can’t afford Ag rims from Kubota, $250 apiece, and Kubota doesn’t sell tires. Researched this site and ran into all that math, which I knew nothing about and Kubota dealer never mentioned. One guy suggested Kenda K378 in a 20x8-10 in another similar post. I like the tread. How close do you really have to get in the math? The tractor will be in 4wd in hilly soil 90+% of the time. I try to never drive in 4wd on pavement.
 

Vigo

Active member

Equipment
B6100, B8200
Jan 9, 2022
318
136
43
San Antonio Texas
The looser the surface, the less it matters that the ratio is not perfect.

20.5 is as far as i know ONLY a trailer tire size. I havent seen any other options in exactly that size. I had 20.5s on front of my 4wd b6100 and replaced them with a similar size ATV tire and ive been happy. 6-12s are a ‘real tractor tire’ in around that same size, and they’re fairly cheap, but you need the 12” rims. If you have 4 lug fronts switching to 12s is easy because 4 lug trailer wheels fit. If you have 6 lug its easiest to just get some atv tires in the preferred size.

As far as size in my opinion its better to go over than under on diameter (by small amounts) because weight on the front will squish the tire anyway (tractor only cares about radius on the squished side thats touching the ground, oddly) and because in my mind an undersize tire might steer worse in 4wd because the back will always be ‘pushing’ the front a little. THAT part is just a theory. 😂