Trying to understand tire size and ratios

[bmaverick]

Often the tire size will include two numbers which are the measurements for the radius and width of the wheel that the tire should mount on. It's not uncommon for a tire to be double labeled in inch and metric. If there is a standard system I don't know it. Yours looks to be designed for a wheel 15" in diameter and 4.50 means a width between the inside mounting faces of 4.5". R usually means the tire is made with "radial construction"
Other numbers usually relate to either footprint or the inflated width of the tire. Rarely is the outer diameter or circumference noted.

For the 5.90x15SL that means the tire is designed to be mounted on a 15" rim with 5.9" between the inside faces. You can mount it on a different width rim. Give or take and inch and it won't matter. Maybe you can get away with even more. All it will do is change the inflated and loaded measurements. But you have to measure those for yourself anyway. Bottom line....will 5.90x15 work on a 5" wide rim? Yes, probably work fine. And it will have a different tread contact with the ground and a somewhat larger circumference.

I've done some 4wd tire exchanges and helped others. The reason to match tire to intenal gear ratios is because it is the easiest way to protect the drivetrain especially for doing heavy loader work or if on high traction surfaces. If you are not doing loader work & can always slip a tire, then matching the ratios doesn't matter so much.

If you are going to change tires and want to match the Front/Rear tires to the Front/Rear internal gear ratios, there are a few simple steps to take first......

First is if you do not have a manufacturer measurement for your tire called: "Loaded Circumference" then you will have to get it by measuring the tire rotation in the dirt - or some similar method. Simple Arithmetic won't work. A loaded tire is not round it is an oval with one flat side. The difference from loaded circumference to arithmatic circumference is larger than the allowable error in allowable front/rear gear ratio.

Second: same goes for the internal F/R gear ratio. If that ratio isn't in your shop manual, you have to measure it yourself. Sometimes the manual is wrong.

Thirdly: match the tire F/R loaded circumference ratios as closely as you can to the F/R internal gear ratio. Try to stay within 5%.

Good luck,
rScotty

Thanks. My machine is a simple 2WD.

Overall I want a tire with the nearest OD in size to what I have with the 5.00-15 because the tractor frame sits level to the ground. This way, I wouldn't need to mess around with re-aiming the headlights. Yanmar didn't make it easy to aim the headlights. It's like open the hood, reach way down there and turn a few fasteners, close the hood properly and locked down, then hop up on the seat and look. If wrong repeat and repeat and repeat. LOL Not like autos where the adjustment is from the outside.

In the past decade or from about 2005 till now, I've notice the rubber tubes having thinner wall section and inferior materials. This goes from bicycle tubes, cart tire tubes, wheelbarrow/tiller tubes, etc. I'm afraid of paying full price on a junk tube and then having the put forth cost once again for a tube AND THEN another remounting fee. UGH.

Those cheaper tubes go bad even during the first instillation rupturing on the seams.

Anyone know of a very good BRAND for tubes these days? And does the manufacture back it up? I'm cringing the thought that putting out up to $200 and with bad tubes going a second round for about another $100 due to the tubes being the wrong selection of brand quality.

 

[rScotty]

Per rScotty's input of the Lead & Lag for 4WD and then adding int the R4 modern hybrid tires, it would be best to run those tire values thru the Titan calculator.

Lead Lag Calculator

www.titan-intl.com

Luckily the lead and lag calculations are just calcs based on numbers which work the same for all the tread types and all combinations as well whether Ag, Turf, or Industrial. The results of a mismatch depend on traction, and that's getting deeper into it than we've gone so far.
Here are some general thoughts about mismatched tire ratios:

It's hard to get into trouble without a FEL regardless of the mismatch.

Another fairly safe combo is a turf or industrial (R3 or R4) tire in hard dirt or any grass. The reason those combos are safe is that a front tire is able to slip traction for a moment which will instantly unwind the stress on the drive train.

Probably the worst combination of events for breaking drivetrains is a 4wd with a FEL carrying a load & wearing R1 Ag tires in deep or sticky soil. .....which of course is exactly where a tractor needs 4wd the most.

And about LEAD/LAG Calculators. The trick to Titan's - or any - calculator is that you have to use the loaded - or as Titan calls it the rolling - circumference. And that dimension is hard to come by online. Rolling or loaded circumference used to be available on request from tire manufacturers, though I rarely see it today. You can't blame the manufacturers, they would argue that it can't be correct unless they know the load and psi. But luckily that dimension is easy for the tractor owner to measure, and more accurate too. The same goes for the mechanical gear ratio. It's best to measure.

I haven't checked Titan's calculator to see if they got their arithmetic right, but it is probably just comparing percentages. Most of us can do that themselves.

What no calculator can do is tell you how much lead/lag is too much. Or too little. That's a whole 'nother subject.
BTW, I didn't use tubes.

Enjoy those nifty Yanmars,
rScotty

Here's an example on our 336D :

 

[bmaverick]

I got a word of mouth that the Carlisle tires are crap on a John Deere, they work sort of OK on the Ford 1000 Series and the xN machines.

One of the better brands of tire is the Alliance 303 F2 5.00-15. I've seen the Alliance on a few machines. They have a sidewall different than most.

ALLIANCE 303 F2 TT

5.00-15 C TIRE ONLY

www.gallaghertire.com

Firestone makes an alright tube. I'm chasing down the p/n ‎532-789. The valve stem is a TR-15 vs. the TR-13. What makes the TR-15 more attractive, it's base is a bigger diameter and better to prevent the valve stem from ripping apart. This is the cause of my current tube problem. It's a TR-13. The hole in the rim is TR-15 sized, so the TR-13 just wiggles and breakage is a greater possibility.

TR 13, TR 15

It pays off browsing the John Deere compact section on a few forums.

 

[rScotty]

I got a word of mouth that the Carlisle tires are crap on a John Deere, they work sort of OK on the Ford 1000 Series and the xN machines.

One of the better brands of tire is the Alliance 303 F2 5.00-15. I've seen the Alliance on a few machines. They have a sidewall different than most.

ALLIANCE 303 F2 TT

5.00-15 C TIRE ONLY

www.gallaghertire.com

Firestone makes an alright tube. I'm chasing down the p/n ‎532-789. The valve stem is a TR-15 vs. the TR-13. What makes the TR-15 more attractive, it's base is a bigger diameter and better to prevent the valve stem from ripping apart. This is the cause of my current tube problem. It's a TR-13. The hole in the rim is TR-15 sized, so the TR-13 just wiggles and breakage is a greater possibility.

TR 13, TR 15

It pays off browsing the John Deere compact section on a few forums.

I've rarely used a tube in any tractor tire. In my opinion, tubes don't help do much good tires on good rims....and having to deal with a tube can make fixing a flat into a chore.

Of course nothing is ever 100% in our world. Last year we had one older R4 front tire go flat on our big tractor & we couldn't find the leak to fix it. Took it to the commercial construction tire shop and they couldn't find a leak either. So we ended up putting an industrial tube in that one. Cheap fix; the tube worked and is still in there. Tubing doesn't always work, but is so cheap it is worth trying on old hardned tires. I'm sure that the time for a set of new front tires is coming closer.

Best place I've found for heavy duty tubes is where the construction machinery get their tires done. They are also cheaper than the Ag tractor supply.
rScotty

 

[ovrszd]

In regards to replacing existing tires, Rolling Circumference Index is what's important.

Here's an RCI chart that I got online several years ago. If it doesn't give you the info you need a Google search of RCI will certainly do so.

 

[bmaverick]

Those ALLIANCE 303 F2 must be very popular because they are out-of-stock at most places or priced thru the roof on existing sites. I can't find the Firestone within a reasonable price. 1X is a mere $118+tax+shipping.

I have a Mavis Discount Tire up the road, but they don't stock the 5.00-15 as normal inventory. Alliance 303 F2 TT | Mavis Discount Tire So it will cost more and there is a delay.

After much digging, the Alliance tires are on back order out of Korea because they are now Yokohama owned.

A middle of the road tire is I can find presently are:

Kit of 2 (TWO) 5-15 B (4 Ply) 69A8 - BKT TF-9090 All Season Tires - Newegg.com

Buy Kit of 2 (TWO) 5-15 B (4 Ply) 69A8 - BKT TF-9090 All Season Tires with fast shipping and top-rated customer service. Once you know, you Newegg!

www.newegg.com

or

Kit of 2 (TWO) 5-15 6 Ply 82A6 - BKT TF-8181 All Season Tires - Newegg.com

Buy Kit of 2 (TWO) 5-15 6 Ply 82A6 - BKT TF-8181 All Season Tires with fast shipping and top-rated customer service. Once you know, you Newegg!

www.newegg.com

From what I gather, the BKT tires or as they call them tyers, are made in India. India has good rubber resources. Free shipping too!

The ASC tires didn't list a brand. That was troublesome. 2X shipped is $188.

Front Tractor Tires, Farm Tractor Tire

This 5.00 - 15 front tractor tire is made of 4 ply tube bias nylon and can carry up to 715 lbs. at 44 PSI with a maximum operating speed of 25 mph.

www.agrisupply.com

rScotty, I hope that I would not need tubes, but the rim design of the Yanmar/John Deere surely says to use tubes because of the hole. hmmmmm

 

[careyo63]

Relined my Org. Bridgestone rear Tires Yrs. ago. Gempler and replaced the Tubes with new. Not the first complaint and saved big money. I put Fix a flat foam my front Yrs. ago. 10!! That even fixed my Valve leak? but it did. Just posted them so here they are, And Rear Pics. also

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[rScotty]

rScotty, I hope that I would not need tubes, but the rim design of the Yanmar/John Deere surely says to use tubes because of the hole. hmmmmm

Someone saying to use tubes "because of the hole" influences me about as much as probably does you.
It just doesn't make much sense.
To make it believeable, I'm thinking an opinion that strange would need come with an explanation. What do you think?
After all, there are an awful lot of tubeless tires and rims out there doing just fine.

https://www.ntstiresupply.com/ptk-shared/tubeless-vs-tube-type-tractor-tires

 

[bmaverick]

Someone saying to use tubes "because of the hole" influences me about as much as probably does you.
It just doesn't make much sense.
To make it believeable, I'm thinking an opinion that strange would need come with an explanation. What do you think?
After all, there are an awful lot of tubeless tires and rims out there doing just fine.

https://www.ntstiresupply.com/ptk-shared/tubeless-vs-tube-type-tractor-tires

I was at the Blain's Farm and Fleet auto store. The ASE certified Tech said to stick with tubes for something that old. He measured the valve stem hole as well. He wouldn't do the work on the tire because it was too far gone with sidewall cracks. However, none of the cracks were even near the bead on either side.

These cracked tires are also 6-ply. Thus, they are loader weight compliant.

 

[careyo63]

I asked Spalding which was Fredricks supplied about the cracks. Tubeless, Steel belted, Would they last. Steve told me then what to do and he was right which I had no doubt. I had to call back a few Yrs. later and he told me Gempler. Took a local tire Co. a couple Minutes. and seeing it done I could have done it. It was only 10.00$ a tire labor. gladly paid it though. https://gemplers.com/collections/ti...ntion-automotive-tractor?_=pf&pf_v_brand=None