MTFCA Forum

Have any of you had luck mounting a 21" tire onto a split rim? I have tried the following with no success: 3 legged tire tool, TWO 3 legged tire tools, wood blocks and hydraulic jack, bumper jacks. In the past I have managed to ruin several split rims by stretching them out of shape in an attempt to make the ends meet or even come close enough to pry together. Countless hours of frustration. Advice would be eternally appreciated!!

Find someone else more experienced with them to do it like I did with mine!

get help from someone locally who has done it - I don't think any amount of words in any combination will fix this problem...only experienced hands will

there is no point wrecking one part much less multiple parts...the hobby is too large and too populated to not be able to find help. I hope your plea will gain you a new friend and possibly salvage one or more rims in the process

good luck

Dont pitch the mangled rims. They are too hard to come by.
They can be straightened with time & patience in a press.
I had to straighten one after a modern tire shop tried installing new tires for a customer.

Best advice already given. If you must do the job yourself, look for past lengthy posts on the subject.
Be gentile. When you do it right, they go together easily.

You need one of these.
viewtopic.php?t=521
I may have an extra one. Dan

Model T 21 inch split rims are fairly soft steel! They bend easily, and with simple effort can be straightened easily. So yes, do NOT throw them out!
If your tire is appropriate size, not shrunk or hard as a brick, the rim should go on easily! I often can install them without using my rim spreaders. Sometimes a common screw driver can lever them together. Often I have kicked them into place with my foot.

Some non-Ford split rims are a lot tougher steel, hence really needing rim spreaders. I mounted a tire on a rim for my 1927 Paige 6-45 and found the rim tweaked just a little. No amount of forcing with rim spreaders and jacks would make that rim line up enough to put the cotter pin in it! I spent about three hours trying. Once I made the decision, it took less than an hour to clamp the rim to an anvil, heat it with the torch to nearly red hot, and bend the tweak out of it. After it cooled, it took about ten minutes to mount the tire and put the pin in it.

Some of it is technique. Knowing the best ways to push what. A lot of that is experience. So, yeah, see if you can find someone close by that has done it a dozen times and can help you a time or two.

There is a certain “trick” to get the rim to meet when the tire is installed. I’ve used a big screwdriver to get it to meet and even up. Take your time and don’t force it is what I’ve learned over time.
Using a rubber ended tire hammer helps to sometimes to get it to move up evenly. Good luck.

Hi Gary,
Yes don't disguard any bent ones they can be straightened I did a set of Chevy's for a guy once. It doe's seem like you are having a lot of trouble
with these. I would try to find someone with experience with them to at least watch you to see if they can figure it out. Be care full one member
of our club broke his arm doing one. The last tire challenge I had was Model AA 20" lock ring wheels. Those are something a atheist can't do
Craig.

A tough one, Craig. I pride myself on doing everything. If I can't fix it, I don't want it. Seriously, I've been working on early cars for over thirty years and am pretty good at it but this one is kicking my behind. I think the issue here is trying to mount old tires on the split rims. Some folks believe that new tires have more give.

So, it's really "The curse of old tires"

and it's funny because I was thinking the only thing that might legitimately lead to multiple bent rims and failed attempts was just that: old tires

it isn't a belief that old tires are less pliable than new tires, it's pretty much a fact. Having done it myself for a friend (and that's the only reason I did it at all), it is something that I can say with experience that it is neither an easy task nor advisable to attempt in the first place.

Old tires don’t give like new tires! New ones are more pliable and that is a fact I’ve that I’ve found when installing them. Yes sometimes you can find some good looking old or NOS tires but time does a number on old rubber.

My late neighbor gave me some 30x3 1/2 T tires he had stored in his attic years before. I crawled up to get them and they were so hard they wouldn’t bend enough to get through the scuttle hole! I did finally get them out by forcing them. But mounting them on a rim was impossible without cracking them as I found out. Live and learn.

Hi Gary,
In my teens I worked for a shop the ouners moto was if we can't fix it we can scew it up so bad that no one can fix it and make us look bad.
I didn't work there long but made more money than I was comfortable with. And learned that integrity is the only thing you can take with you
in the end so get all you can when you can.
Craig.

wise words men!

I can't figure out why but it seems that the three legged tool causes the rim to twist. Ends never seem to line up properly. I'm using old tires but surely this couldn't be the issue

I find that with old tires (I am terrible about using old tires!), sometimes, the only way to get the rims to spread and line up is with two rim spreaders, one from each side. Otherwise, the stiffness of the un-spread side of the rim does cause the rim to twist as the tire doesn't give enough.

We had mounted 4 Universal tires on our 26 years ago and needed to have 2 replaced. The new Universal tires were extremely difficult to mount. It was as if they were too small diameter. But after using the 3 position spreader and bending it, the tires went on. After mounting and using the tires we found that they were not round where the they meet the pavement. So after all the trouble to mount they are not useable after all. They went on wood spokes and then on to replacement metal spoke wheels. Same results.

Calling the supplier I was told that the same brand may have the same issue if same brand tires are ordered. They suggested a change to another better brand should give better results. There was no offer to help with price either.

Jeez, when I bought my '27 It came with five brand-new Firestones and it needed them. After removing the rims from the wheel, the only tools that I used were a valve core remover/replacer, two large screwdrivers, and a rubber mallet. I spent far more time cleaning out the rust and guck from the rims then I did physically doing the tire swap. The split rims made it easy. Oh, and I replaced the duct tape with real flaps.

Just did two this AM these are harder to do then a clintch in my opinion
Used the three jag rim tool
Here's what I did
Tube in tire enough air in tube sorta round?? Still very soft 5-10 psi
Took rim tool compress the rim as far as I could meaning about 3" overlap
Stem of tube in the hole and tire iron put the tire on
Then removed the rim tool
Put it in the rimtips of the tool where the fellow would be now spread the rim to lockit
Now tocation of this rim tool is important
Put the one leg about 4" +/- from the inner end other opisight of that
May not be right way but got two mountedand locked
All I can say I can do cl8ntcher in 15 minutes and only do slit rims once in a blue moon

My 2 cents worth - after wrestling the rim back together & locked, I'll only air up to 6-8 lbs., bounce it around a couple times then BOLT it up to the wheel BEFORE airing it up to the recommended pressure - I actually had a rim blow apart whilst airing it up !!!

This is how I did it.


https://www.youtube.com/watch?v=WKfaDDEkrx4&t=28s

I used two tire spoons (long ones from Harbor Freight) Make sure your head is out of the way when you're pulling on them. Don't ask me how I know.

The Canadians may have it easier, if they have the proper tool to do the job. Canadian split rims have a pair of holes on either side of the split, on each side of the rim. The proper tool engages these holes and pulls one side of the rim under the other and collapses the rim. By pulling on both sides, there is no tendency for the rim to buckle or distort. I have only ever had one of these tools, so they may be really scarce.
On any split rim, a flap should be mandatory equipment. This is one place where any kind of rim liner will make restoring the joint in the rim problematic.

Allan from down under.

Here is an older thread on how to install tires on split rims.
https://www.mtfca.com/phpBB3/viewtopic. ... 94#p236803

I have found this tread to be quite helpful, but I need to find a pair of rear tires for a 1925 Model TT Farm Truck. The tires that that need replacing are Firestone Gum Dipped 32 x 6 HD. I don’t believe that they make these any more, but I am having trouble figuring out an equivalent or replacement. The wheels are wooden-spoked, split rim. What do I need to measure to find something that fit?
[image]/Users/sheila/Pictures/Photos Library.photoslibrary/resources/derivatives/E/ED3B1546-B7B5-4664-973D-67E358503A31_1_105_c.jpeg[/image]

SheilaD wrote: ↑

Thu Jul 03, 2025 12:49 pm

I have found this tread to be quite helpful, but I need to find a pair of rear tires for a 1925 Model TT Farm Truck. The tires that that need replacing are Firestone Gum Dipped 32 x 6 HD. I don’t believe that they make these any more, but I am having trouble figuring out an equivalent or replacement. The wheels are wooden-spoked, split rim. What do I need to measure to find something that fit?
[image]/Users/sheila/Pictures/Photos Library.photoslibrary/resources/derivatives/E/ED3B1546-B7B5-4664-973D-67E358503A31_1_105_c.jpeg[/image]

Actually, this thread is of no use to you. Your wheels are "lock ring" not split rims. Thats a whole different kettle of fish.
I can advise you be careful not to pretzel the lock ring during its removal & installation. Make sure the ring fully seats before airing up.
This type of wheel can be dangerous. Air up to the side in case the ring blows off, It can kill you.

Not an expert on TT's. I suspect the tire is a 20". Look for the information in other threads.

Hi Sheila, The formula to convert your 32 x 6 tire rims to the modern size is: 32 - (6 x 2 = 12) = 20 inch rims.
and these take modern 600 x 20 or 650 x 20 tires and they can be mounted on the split rims that you have. That said, you must be very careful when mounting tires on split rims as mentioned on the posts above.
I hope this helps.

Keith

I beg to disagree Keith, but those are not split rims - they're straight sided "Widow Makers" w/split ring - best left to a commercial truck tire store ! And they will take a 6:00 x 20 tire.

Sheila's wheels are like most truck wheels, prior to the development of tubeless tyres. The rims are made with only one side to hold the tyre on. The tube, flap and tyre are installed as a unit and the whole is dropped over the rim, which is NOT split. The second side of the rim is a separate lockring which when fitted slots into a recess in the rim. This lockring must seat perfectly in the recess or there is a chance it will explode off the rim as the tyre is inflated, with fatal consequences occasionally. Some wheels had two separate rings. One that holds the tyre on went on first. Then a second ring locked the first in place. This innovation was meant to be safer, but caution was still needed to make sure it was properly seated in the receiving groove.

10.00 x 20 inch truck tyres are big, heavy and unforgiving, but they drop onto rims, regardless of their age, because the steel wires in the beads maintain their size without any shrinkage. 21" straight sided T tyres are the same. Old or new, the diameter remains the same and they should fit in the same way. 30" clinchers are different. With no wire in the bead, they do shrink. Old, hardened clincher tyres can be impossible to fit, as they must be stretched over the bead on the rim. Any attempt to lever them on may well just mean breaking the hard rubber at the bead. Don't ask how I know this to be true.

Allan from down under.

I think truckers call them split rims but in the Model T world they are called lock rings. When I entered the hobby I also was confused for awhile. I finally found the difference between Model T split rims and rims with a lock ring.

I used a turnbuckle to collapse mine. Used Harbor Freight tire irons. Soapy water. To spread the rims again after changing the tube I used a hydraulic Jack and 2x traced to the inner diameter. Hardest part was keeping the valve perpendicular to the rim. Had to adjust it several times and predict where it would end up.

To Steve and the others who mentioned it, yes these are lock ring wheels. I didn't even pay attention to that but was concentrating on the tire size and merely continued on with the split rim concept that this thread started with. You guys are right, the wheel picture she posted is a lock ring wheel and they can easily be very dangerous if not mounted and inflated very carefully.

Keith

Whether lock rings, or split rime the mounting is easy if you follow these simple steps....

For those with AAA or other roadside assistance, make the call. Speak very slowly and directly (for the quality control recording) that you have "a tire that needs changing". When the poor man arrives and starts to scratch his head tell him that you have all the tools. Upon his excuse that "we don't do that" explain very clearly that you specified very clearly the year, make, and model on the phone. Also show him a wheel and a tire and explain that you very clearly said you needed a tire, not a wheel changed. As he will be at a loss and refuse your next option is to contact AAA, threaten with a lawsuit and take the money to buy a new set of tube's, tires and flaps which will have rubber far easier to work with....

Here is my Hercules split rim tire tool. I used it to change all four of my 52 year old, rock hard Universal tires. The more you do, the easier it gets. Notice where the split is in Cut No. 4. Just follow the instructions. Use talcum powder. Good luck.

Gary,
I mounted all five tires on the rim myself using the three legged tool. The old tires were so hard that I had to saw in some cases. The replacements were new pliable tires. When compressing the rim, if I saw the rim start to distort, I backed all the way off and placed the tool on the rim in a different orientation and tried again. It was a learning process. Other have shown specific ways to do this but even so, if YOUR rims begin to show signs of damage, then move the tool location.

On an other note, I used to drive a 1973 Ford Ranger Camper Special with 16" split rims. This is what Ford has to say about it: