Farmall B Rear Wheel Rims Question

I am currently in the process of restoring my 45 Farmall B with my students. The rear rims are severely rusted through an I am wanting to replace the rims with new ones. The hubs (or whatever you call the center of the wheels) are cast iron. I am wanting to go with a narrower tire than the 11.2x24 that are on it now.

Can I bolt a 7x24 rim from a Cub onto the cast centers or is the 8x24 as narrow as I can go?

The reason I want the narrower rims is 1) So that the tractor will fit on my trailer and 2) when I have chains on them I don't want the chains slapping the fenders while I'm pushing snow.

I'm not too worried about what is accurate for this tractor as I am putting a wide front on it and live hydraulics from a Farmall C. There's lots of well restored B's out there and I like to be different. Just look at my Farmall H if you are wondering how different I like to be.

http://teacherweb.com/IA/SoutheastPolk-HighSchool/McCoy,Steve/photo3.aspx

There were actually everything from 7-11" rims made for the As and Bs.

If you can find a 7" rim (I have no idea how common they are) you could do what you want. But I think you could also do it with 9.4x24 tires on 8" rims. Don't know what you have for a trailer, but the typical car hauler is just about 7' between the fenders. The narrowest treadwidth for a B is 64", and you have to add the width of one tire (half the width of two tires), so with 9.5s you're up to 73-1/2. You'd still have room to move them out 4" on each side enough for your chains to clear, but bungee up the loose ends) and get between 7' fenders if that's the target. That extra 8" of width is gained by dishing the wheels in and mounting the rims with the inside of the lug mounted to the side of the wheel closer to the tractor, so that the wide side of the rim is away from the tractor.

I'm just suggesting 8" rims and 9.5 tires might be a lot easier to come by and still accomplish what you want to do.

My trailer is only 76" between the fenders. Right now the tractor is 79" inches wide. I didn't know they made a 7" rim for the A's and B's. I've seen where I can buy 7" rims for a Cub. I'll have to do some more searching to see what I can find. Otherwise I'll probably go with the 8" rims. Thanks.

I doubt you will be able to both fit the tractor on your trailer and have clearance for chains with the tires set at the same width. Not likely to have room for chains with a 64" treadwidth, even with 8.3 tires on 7" rims.

To answer your original question, The bolt circle of the Cub rims is not quite the same as the A/B rims. They do not directly bolt on. The offset of the lugs is different too. If the bolt circle matched, the narrowest treadwidth would be 66".

That's what I was wondering if the 4 bolts would line up the same as the A/B rims. Hopefully going with 8" rims will be enough to squeeze the tractor on the trailer.

I only more it in the summer anyway so the chains wouldn't be on it then.

I don't see how I could [i:e9d5a13c0c]ever[/i:e9d5a13c0c] get the B as narrow as 64" or 66." Correct me if I'm wrong but that's got to be for a BN or something. Mine's just the plain ol' B. I'm just looking to get 3" to 4" inches narrower is all.

I assumed having chains on while loaded on the trailer was out of the question. What I was trying to say earlier is I doubted you could transition from mounted chains to fitting on the trailer without resetting the treadwidth.

The treadwidth both Scott and I were refering to is the measurement commonly called "treadwidth", "tread" or "track". This is a standard measurement from the CENTER of one tire to the CENTER of the other. As Scott stated in his first post:

The narrowest treadwidth for a B is 64", and you have to add the width of one tire (half the width of two tires), so with 9.5s you're up to 73-1/2.

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Understandable, your concern, but 64" is the minimum treadwidth for a B. (On a BN, it's 56") The trick to that is that it's measured to the center of the tread. So you have to add half the width of each tire, twice, or the width of one tire as it works out, to get to the overall width.

The very narrowest width is achieved by dishing the wheels in, and mounting the rims to the sides of the wheels nearest the tractor, and the outside of the rims mounted to the wheel, so that the offset of the rim is toward the tractor.At this width you can be sure that any chains swill beat on your fenders.

Four inches wider (68"), you keep the rims oriented the same, (offset to the inside) but mount them to the outsides of the rims. (At this width, good tight chains with the looses ends bungeed end might clear okay).

Four inches more (total of eight, to make 72) you move the tires and rims to opposite sides of the tractor (to keep your tread working for you), and mount them as I described in the first post, to the insides of the rim with the wide side of the offset to the outside. (Chains shouldn't be a problem at this width -- you'll have 4"+ clearance between your tires and fenders.)

That's as wide as you'd want to go if you find you have to back the tractor on to get your load balanced for hauling, since you'd have to get the rears through the fenders to get backed on fare enough.

If with that wide front, the front is heavy enough that you can balance your load pulling one, you can go one more increment of four inches, to 76", by keeping the rims oriented the same as 72" and moving them to the outside of the wheels.

After that, you dish the wheels out and start over in the same order to get to a full 92" tread.

I got all carried away with the concept and completely left out consideration of the tire width. add 9.5 or 8.3 to everuything I just said. (I was having a gray moment. Apologies)

SO . . . with 9.5s (on 7" or 8" rims, makes no real difference) set to the narrowest, you could squeak through the fenders. Setting them up for a 68" treadwidth, with 9.5s would make you to wide for your 76" gap between fenders. Even 8.3s would scrape, regardless of your rim width.

Do your shot rims have tires that will hold air long enough for a test? Try balancing the tractor for hauling. If you can set the wife front up narrow enough to drive it on (as opposed to backing it) and get the tractor far enough on to balance without having to get the rears between the fenders, then you can set them out enough for the chains to clear. But you'll want to have it chained down well, and check often to make sure it stays put if your tread is that close to the edge of the deck.

If you have the cast centers they are thicker than the steel ones. Now you can use the 7in rims on the B then use a 8.3x24 tire. If you use the 8 in rime the 9,5 will fit good. The 8.3 will be 72 wide on the 7in rims. You will not have clearence with the 8in rims set in the narrow position as the rim will hit the final drive the rim will have to be mounted outside of the center. Mite want to call me im sw of ia cityand have several Bs with different tires i do have some original rims 319-430-3907

I think Jim is thinking about the centers when he says different e with the Cub. The rims have the same spacin to bolt to the center. If you need to be that narrow you need 7in rim with the 8.3 You can get new ones delivered to your front door with tubes for a little over 400 original type and 6ply.

From what others have posted I don't know if a cub center hub lug holes will bolt to a B.
But if they will, you might try getting a set of rear one piece wheels and tires from an IH 154-184-185 and bolt them in the narrow position.
If they will bolt you will be good to go.
The guy that can tell you for sure is hamiltonbobscubs.com
Dell

Thanks guys. A lot of good advice and suggestions here.

I understand now about tread width being measured from center to center of each rim. (Sorry I missed that earlier)

Cub centers have 5 bolts while A & B centers have 6.

Another option I am considering is using a blank rim (sold without hoops) and welding the hoops on myself. I've heard people talk about doing this with truck rims except truck rims are typically 24.5" in diameter.

I'm going to have to get the wheels off for the kids to get the frame all cleaned up. Might as well do some experimenting with how the rims are mounted to the centers.

Does anyone know how different a cub rim is from an A/B rim? Wouldn't the hoops be spaced evenly around the rim a 0, 90, 180, and 270 degrees? or did the cub space them differently for some reason? (never know with the ol' IH engineers)

Thanks again.

Does anyone know how different a cub rim is from an A/B rim? Wouldn't the hoops be spaced evenly around the rim a 0, 90, 180, and 270 degrees? or did the cub space them differently for some reason?

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Like the A/B rims, the lugs are set at 90 degree increments. The other 2 aspects are different, as I stated in my first post.