Trying to understand tire size and ratios

[careyo63]

9.5/9 - 24 Bridgestone on mine. I believe they're Org..

 

[bmaverick]

Old thread, but the OPs original posting sheds the best light on Ag tires of the old x.xx-xx sizes to the new IF-sizes that are metric based. My front tires are cracking badly only after 8 years (Milestone, China made). Replaced 1 tube in November, now the other front wheel tube is shot. The tubes will not hold up as the tires are too weathered. So, I got to find or put on order something very soon as Spring is nearly here for tilling!

My YM2610 Parts Manual shows the fronts are 7.00-16 or 5.00-15. The 5.00-15 = JD850 and other JD Yanmar machines. Thus, it shouldn't be too hard finding tires right? LOL

Well, I got sort of displaced looking for the 5.00-15's because a majority of the Ag tire charts to the IF-size conversions begin with the 6.00-14.

Is it that hard to find SCUT and CUT 2WD tractor tire size conversion?

Additionally, the rim mentions 4.50E. Not a clue as to what that means either. It's the same on a JD750, JD770, JD850, JD870, JD950, JD970, etc. for 2WD front tire options.

I'm fine hunting for vehicle tires. Ag tires are not so straight forward yet to my thinking.

Looking locally at the Farm and Fleet store, they have a 5.90x15SL. Would this mean the tread area is 5.90 inches wide vs. what I have now as 5.00 wide? Or is that the profile height of the tread, thus I have it all wrong.
https://www.farmandfleet.com/products/636195-farm-specialist-4-ply-implement-i-1-tire.html

Anyone here with some insight?

 

[rScotty]

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

 

[California]

Looking locally at the Farm and Fleet store, they have a 5.90x15SL. Would this mean the tread area is 5.90 inches wide vs. what I have now as 5.00 wide? Or is that the profile height of the tread, thus I have it all wrong.
https://www.farmandfleet.com/products/636195-farm-specialist-4-ply-implement-i-1-tire.html

Anyone here with some insight?

Dunno about insight, how about just unsupported opinion?

Stuff I've read FWIW - I've read that the first number is the width of the casing, relevant for a truck's duals, for fender clearance, etc. But we've all seen cheap tires that are smaller than quality tires of the same nominal size. Then on car tires, the -70 etc is the proportion of height to width.

But relevant to our Yanmars: Here's a photo showing two similar tires that are vastly different in size.
500x12 vs 5-12.

5-12 is what Yanmar specified for the front of YM186D. Apparently an obsolete spec and hard to find. But the big ag tire wholesaler/dealer for California's Central Valley (huge ag region) had a pair in stock.

The taller 500x12, in contrast, is what was on my first YM186D when I bought it. That tractor had been used mostly for blading snow so its front/rear ratio mismatch hadn't caused any damage but I expect if it were run on dry pavement it would have bound up badly.

(I put the used proper 5-12 tires on that tractor before I sold it and bought new 5-12 tires for my second YM186D, the one with a loader).

So - I think its necessary to find the precise size Yanmar specified, to avoid a mismatch as bad as this. Good luck finding them.

=============================
And a note to the moderators: I first posted that photo here on February 4, 2014. It shows in my list of attachments. But:

Forums

Couldn't find that...​

You do not have permission to view this page or perform this action.

when I went to re-use that photo for this post. Same response for the post itself.

So I found the original on my HD and that's what I uploaded to show here.

Details
Old photo: https://www.tractorbynet.com/forums/attachments/p1740817rtire500x12vs5-12-jpg.358886/
Old post 2-4-2014 that included the photo: https://www.tractorbynet.com/forums/posts/3646885/

Can this 'no permission' problem be remedied? Is somebody tired of my opinions?

 

[MossRoad]

If you could make a detailed post in the News/Feedback forum it would be appreciated. That way we won't contaminant this discussion with those details. Once your post is over there, I'll make a point to get a PM to the owners to see if they can see anything amiss. The moderators don't have any control over that kind of issue.

 

[California]

If you could make a detailed post in the News/Feedback forum it would be appreciated. That way we won't contaminant this discussion with those details. Once your post is over there, I'll make a point to get a PM to the owners to see if they can see anything amiss. The moderators don't have any control over that kind of issue.

Thanks Moss. I forget if it was here or on (unrelated) WeldingWeb that old threads were in folders that got re-named when the site software was updated. So any link - in this case where 'Attachments' thinks the old post resides, instead link to nowhere.

 

[winston1]

Old thread, but the OPs original posting sheds the best light on Ag tires of the old x.xx-xx sizes to the new IF-sizes that are metric based. My front tires are cracking badly only after 8 years (Milestone, China made). Replaced 1 tube in November, now the other front wheel tube is shot. The tubes will not hold up as the tires are too weathered. So, I got to find or put on order something very soon as Spring is nearly here for tilling!

My YM2610 Parts Manual shows the fronts are 7.00-16 or 5.00-15. The 5.00-15 = JD850 and other JD Yanmar machines. Thus, it shouldn't be too hard finding tires right? LOL

Well, I got sort of displaced looking for the 5.00-15's because a majority of the Ag tire charts to the IF-size conversions begin with the 6.00-14.
View attachment 735968

Is it that hard to find SCUT and CUT 2WD tractor tire size conversion?

Additionally, the rim mentions 4.50E. Not a clue as to what that means either. It's the same on a JD750, JD770, JD850, JD870, JD950, JD970, etc. for 2WD front tire options.

I'm fine hunting for vehicle tires. Ag tires are not so straight forward yet to my thinking.

Looking locally at the Farm and Fleet store, they have a 5.90x15SL. Would this mean the tread area is 5.90 inches wide vs. what I have now as 5.00 wide? Or is that the profile height of the tread, thus I have it all wrong.
https://www.farmandfleet.com/products/636195-farm-specialist-4-ply-implement-i-1-tire.html

Anyone here with some insight?

May not be right but here is what Hoye shows for the 2610. 4-15 FRONT TIRE - RIB STYLE (2WD)

 

[bmaverick]

May not be right but here is what Hoye shows for the 2610. 4-15 FRONT TIRE - RIB STYLE (2WD)

In the YM2610 Parts Manual, both 7.00-16 and 5.00-15 are listed. Glad Fredricks didn't use the 7.00-16 because that's even a harder find.

5.00-15 is a very common John Deere size too as I had mentioned prior. And for the same price, ASC has the match. Front Tractor Tires, Farm Tractor Tire | Agri Supply, 16572

Firestone has them too, but the store that also do Ag are a wee-bit further away.

Should I ever get a loader for the YM2610, the 5.00-15 would be ideal over the 4-15 for capacity load rating.

So, $60+shipping unless I can find a pair on Amazon with free shipping.

Tubes are $18 to $24 in my area. And those are not the good ones that would last years. I need the industrial type with the thicker wall thickness. $$ unless others here have found a good trusted brand to snag.

 

[richriddle]

This thread proved an interesting read. Is there a way to figure out how to select R4 tires. Those weren't much of a consideration in the day when Yanmar manufactured most of our tractors.

 

[bmaverick]

This thread proved an interesting read. Is there a way to figure out how to select R4 tires. Those weren't much of a consideration in the day when Yanmar manufactured most of our tractors.

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