12.4 vs 13.6 On The Road.

Bryce Frazier · Sep 9, 2015

What would the speed difference be between these two sizes running down the road?

My Farmall H boogies right along, little too quick to be honest. I am taking the 13.6's off of it and putting them on my M, and then I am putting a spare set of 12.4's onto my H. Will they slow it down a little? How much? 1 or 2 mph maybe?

Ultradog MN · Sep 9, 2015

Bryce,
This is a simple arithmetic problem that you could figure out yourself.
Google tractor tire diameters and there are several charts out there.
Then do the pi X dia to get the circumference of each tire.
Then figure what % smaller the 12.4 is than the 13.6.
That will be the % slower you will get.
BTW,I assume your H has 38" tires?

onefarmer · Sep 9, 2015

I don't think you would notice the difference. I have both a H and M. Sitting a bit lower on the H gives a bigger feeling of speed.

Putting the 12.4 on the H and 13.6 on the M puts the correct tire size on each anyway.

Eldon (WA) · Sep 9, 2015

(quoted from post at 09:19:27 09/09/15) Bryce,
This is a simple arithmetic problem that you could figure out yourself.
Google tractor tire diameters and there are several charts out there.
Then do the pi X dia to get the circumference of each tire.
Then figure what % smaller the 12.4 is than the 13.6.
That will be the % slower you will get.
BTW,I assume your H has 38" tires?

Tire circumferences can vary quite a bit tire to tire depending on tread, manufacturer and tire air pressure. Most accurate would be to measure the circumference of your tires and calculate the percentage difference.

Ultradog MN · Sep 9, 2015

The point is to get him to do the math.
He will use it all his life.

RLA · Sep 9, 2015

I'll put it this way, Your H still won't have any power on the hills in 5th gear, but it will
be a tad better... my guess would be the H will be about 1.3 mph slower.... Just a guess..

pete 23 · Sep 9, 2015

Measure center of axle to the ground for rolling circumference calculations.

BushogPapa · Sep 9, 2015

If ya don't put some liquid ballast in the tires, they will have more "Bounce" when you 1st start out or hit bumps on the road..

I like the 13.6x38 over the 12.4x38" on my Late Styled JD "B"..much better flotation and traction.

I have a loader on it for all-year-round use..

Ron..

BushogPapa · Sep 9, 2015

15,5x38" work well on an IH "M"..if you can find a set..

Ron..

2underage · Sep 9, 2015

He is still in high school and gets all of the math he needs now. His question was will it make much difference in the speed of the old IH "H" and the answer is yes a little but not as much as the math indicates but because the engine will have a little less load and will run a little faster thus your travel speed will be about the same.

Bob Harvey · Sep 9, 2015

Happy now ?

David G · Sep 9, 2015

Yup, I am kind of surprised he did not know.

Bryce Frazier · Sep 10, 2015

Ya no joke....

I REALLY liked the 13.6's on my H for field work. In our slimy clayish slop up here, I was able to get it stuck twice, one time was just stupid on my part, but the other time, I should have crawled right through the stuff.... :/

My SC has 11.2's on it, and those SHOULD be 12.4's in my oppinion... Just a little bit bigger.

I don't run fluid in any of my tires either. Only on the JD's. I have LOTS of IH wheels weights, the H has 3 sets, the SC has 2, and the M will have 3, maybe 4 depending on what I have!

Thanks! Bryce

Bryce Frazier · Sep 10, 2015

I knew these things were gutless on the hills, but I must say I am surprised at how well this on does right now... But it is just toooooo fast for me! Would love it if it rolled along at 13 or 14 mph.... That would be fine...

12.4 vs 13.6 On The Road.

Bryce Frazier

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Ultradog MN

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onefarmer

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Eldon (WA)

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Ultradog MN

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RLA

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pete 23

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BushogPapa

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BushogPapa

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2underage

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Bryce Frazier

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