Measuring Rear Rim Size and Difference in Ride Height

Apparently they made a 9 inch wide and a 10 inch wide rear for Farmall Super A, 100, 130, and 140 tractors. Had a guy stop by needing a rear rim for a Farmall 130 and I got him fixed up with an extra (had a bad tire mounted) I had. He called complaining that the rim I gave him was 1 inch wider than the old one and that made the tire sit lower on that side.

Question.....will that cause it to sit lower? Another question.....I have A few other rear rim's that have bad tires mounted on them. Is there a way to measure the size of the ram without having to take the tire off? What actual dimension are they referring to?

(quoted from post at 18:52:29 10/15/18) Apparently they made a 9 inch wide and a 10 inch wide rear for Farmall Super A, 100, 130, and 140 tractors. Had a guy stop by needing a rear rim for a Farmall 130 and I got him fixed up with an extra (had a bad tire mounted) I had. He called complaining that the rim I gave him was 1 inch wider than the old one and that made the tire sit lower on that side.

Question.....will that cause it to sit lower? Another question.....I have A few other rear rim's that have bad tires mounted on them. Is there a way to measure the size of the ram without having to take the tire off? What actual dimension are they referring to?

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nside, from bead seat to bead seat.

If there was any difference in height with a wider rim, it would be so small it would be hard to measure. Inflation pressure and tire would be a greater factor. Your customer is a complainer. I measure height on ATV's by adjusting air pressure until both on same axel are same height rather than using a pressure gauge

It won't be exact, but close enough. If you have an old pair of tongs (ice tongs, hay tongs, etc.) put them over the tire and touching the rim, then make a pencil mark someplace near the pivot an both halves, take it off the rim and re-align the marks and measure between the points.

I wouldn't think it would make a whole lot of difference. He is just trying to get something for
nothing.

customer is correct having the tire and rim match is important in those sizes. You measure the rim outside to outside then minus 1inch gives you rim size thus an 8in rim will measure 9inches out side to outside

I take it you haven't had any experience with those sizes tires and rims on those tractors

I'll go along with Bender and say the customer has a legitimate issue. Rim width can affect
tire height.

(quoted from post at 22:09:48 10/15/18) customer is correct having the tire and rim match is important in those sizes. You measure the rim outside to outside then minus 1inch gives you rim size thus an 8in rim will measure 9inches out side to outside

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ome very, very thick half inch metal on your rims! Should NEVER rust out! 1 :roll:

It will have to positively have to make a difference. Just lay a string out on a table top around five article to hold corners in order to pull any two apart the fifth will have to come in. I don't think that it should be more than 1/4 inch but the difference will be there.

I have 2 tractors with 13.6x28 with (on a 12" rim) stamped on the side of the tires and I know the rims to be 12" as I measured them when changing.

I have another I recently purchased without the notation (on a 12" rim) on the tires......all tires were F1 with over an inch of lug showing. I'm assuming that tire is made to ride on a 13" rim and I
assume what is on the newer tractor. To look at the two tractors side by side the latter just looks larger and the wheels were made in '88 rather than '63 or '65 like the other two....has fewer
mounting points for one thing (Ford wheel dish to tire wheel interface) so there could be some uniqueness there. I may just go out and measure since this topic came up then I'll know for sure;
idle curiousity.

I do know that tires have a static OD dimension and a dynamic due to compression of the tire at the point of ground contact.....some tire charts spec both (radial charts as I recall) and the
conditions.

With that said and having gone through a lot of tires in the process of getting a soft riding with good traction lawn/pasture mower I find significant variances in specified dimensions vs actual
measured under different wheel sizes and conditions especially with low ply (2-6) bias tires. I can support the axiom that tire size differences can occur depending on ply type, air pressure/load
carried, or wheel mounting width differences.

Remembering, as I was buying that last Ford, I thought it had 2 different OD rears since it was sitting at a tilt. Observing, they were of different mfgrs, same dimension specs, ( ply ratings and
type) and wheels, only to find out later that one had around 15 psig in it and the other less than 5. Air pressure definitely did have an impact on appearance....with no visible bulge you see when a
tire is low on air pressure to give you a clue that it's low.

(quoted from post at 05:23:32 10/16/18) It won't be exact, but close enough. If you have an old pair of tongs (ice tongs, hay tongs, etc.) put them over the tire and touching the rim, then make a pencil mark someplace near the pivot an both halves, take it off the rim and re-align the marks and measure between the points.

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Does anyone have a good picture showing exactly where to measure for this deminsion? A good way to measure it with the tire still on is what I'm looking for. I think I could tape a wood ruler to a tape measure to act as a "caliper".

if measure outside, then subtract 2X metal thickness.

Thickest material used to roll farm tractor rims is .187 inches thick, so two thicknesses, subtract .375 inches. Little rim like on a Farmall A probably .125" thk. so subtract 1/4 inch.

+1 on the red line for the measurement.

(quoted from post at 21:59:21 10/16/18)

if measure outside, then subtract 2X metal thickness.

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Thanks to all of you who replied. I ended up taping a paint stick to a tape measure at 0 inches and one at 10 inches so it would hinge back to 9 inches if needed. I measured a couple of Farmall Super A rims and a couple of Farmall 140 rims and all I found were 9 inch rims. I measured rims that had tires mounted at the point you showed.

Did these tractors all have 9 inch rims and the aftermarket ones are 10 inches?

Here's one way to measure a rim with a tire mounted on it.

Lay the wheel on two 4x4s on the floor with one of them centered in the middle of the rim then lay a 2x4 on
top of the wheel directly over the centered 4x4.

Measure the distance from the inside of the 2x4 to the bead seat area of the rim. Double this measurement
and subtract it from distance between the inside of the top 2x4 and the inside of the bottom 4x4.

Hope this makes sense. I've used it several times with good results.