Tire size on the A

[Capnball]

Hey guys, here's something that's bugging me: I will be buying tires for the A asap, and all the manuals and such specify 8x24s as standard equipment, and larger and smaller sizes as optional. I always see 9.5s and larger on A's, and I was wondering about 8.3's. I realize those look really small, and that I would need the proper size rims, but I was curious to know what y'all think. Have tire sizes changed much? Which size is closer to the original 8x24 specified in the manuals? Supposedly tire size can make a slight difference in transfer of power to the ground, as well as speed, and I sure would mind lower speeds while doing things like cultivating. How about looks? Anybody got pics of an A with 8.3s on it? Thanks ahead of time!

[Super A Farms]

Here is my 1940 with original 8.3x24 rears

[havoc1482]

Edit: I actually think I have 9.5s but I cant remember because it always seems to me that my tires are smaller than every other A\Super A I've seen

I will say that tire size isn't going to have much effect on ground speed in anything less than 4th. Just Look at the AV and Super AVs, wheels were huge.

[Boss Hog]

I would not consider anything smaller than 11.2s just my opinion, if you plan on using it for anything other than riding it

[Dale Finch]

I ended up with the 11.2's. They REALLY look big by comparison here:

but they actually are proportional once installed!

[Matt Kirsch]

I usually get the dashes and exxes mixed up, but there are two ways of denoting tire size.

A tractor as old as a Farmall A would have originally used the old way, which was 8-24, using a whole number to indicate width. Some time in the 1950's, tire manufacturers switched to a decimal number to show width, with the number often being much larger than the old whole number width.

AFAIK, old size 8-24 is equivalent to 9.5x24 in a modern tire.

[Denny Clayton]

The 8-24 size became 8.3-24.

[twotone]

I put 12.4's on my super A.

[Capnball]

Thanks guys! Especially for the pix. Wonder how those original 8s actually compare to new tires in measurements. I did find some interesting info in this FAQ page on Miller Tire's website: http://www.millertire.com/faqs/ Check it out, and tell me what you think. If they're right and I'm reading them right, then a 40s era 8x24 would be more like a modern 9.5x24.

[Capnball]

My A has a set of modern 11.2s that are ruined from sitting too long without air in them. They would have been great tires; not much wear at all. I think I'm leaning towards the 9.5s now.

[Gordon1121]

I've was reading this post and thought I'd share my experience with the new tire sizes. The first pic is our 100 with 10.5 Firestone field and road which were worn down pretty good and the next is with new Titan 11.2 although a little different angle you can see cover a lot more fender. I have a 130 with the 9.5 and the 100 with the 11.2 Titan. I don't know if it makes a difference or not but it did make it harder to get on by some bit and if you plan on using it you cant run as narrow a row. To me the new 11'S are more like the old 12'S.

[Capnball]

Thanks for all the input, guys. I'm really liking the looks of the new 9.5s, but I'm not sure how they'll mount up on my rims...

I had the old tires taken off today, and the rims are 9" rims. Can I mount a 9.5 on these rims, or will I be forced to go with an 11.2? Does anyone have pics of 9.5s mounted on 9" rims? What do y'all think? I see modern 9.5s are normally mounted on 8" rims, and 11.2s on 10" rims- but I can't find anything on 9" rims.

Also, what about fronts? Have front tire sizes changed over the years too? Assuming they haven't, I was planning to mount 4x15 tires on my original 3x15 rims- or do I need 5x15 tires? Really confusing.

[Matt Kirsch]

Where did you measure the width of the rim? IIRC, the rim width is measured BETWEEN the beads, not to the outside of the flange.

Odds are you have 8" rims, but even if you somehow ended up with the only two 9x24 rims in the known universe, your new tires will stretch slightly to fit them just fine. As a rule of thumb you can go up or down one size of tire on a given rim with no issues either in looks or functionality.

[Jim Becker]

The As and Super As originally equipped with 10-24 tires had W9-24 rims. The replacement for that size tire is 11.2-24 which is now usually put on a W10-24 rim. 9-24 tires came on a W8-24 rim. I would not hesitate to put 9.5-24 tires on either size rim.

The original 8-24 tire (now 8.3) was on a W7-24 rim. I would not put that size tire on a 9-inch rim.