Will 4.40-4.50 x 21 tires work with demountable rims?
I've never seen a 21" demountable rims. If there is such a thing as a 21" demountable rim then yes. I've only ever seen 30 X 3 1/2" demountable rims. You must use a tire size that fits the rim in question.
What size are your rims?
Royce, as you can see, I am confused as are many others. I do know that some 1923 Touring cars cam with demountable rims with 30 x 3 front and 30 x 3.5 tires on the rear. And I have a couple of 4.40-4.50 x 21 tires. so will a 30 x 3 tire use a 24" rim and a 30 x 3.5 use a 23" rims? Later today I will measure my rims and wheels etc. so I have a better understanding of my original question.
21" tires fit on 21" demountable rims, which were used 1925-1927. The rim is NOT a solid clincher rim, but a collapsible rim.
The 21" tires are also used on wire wheels 1926-1927.
I hope this helps.
I have 21" demountable rims and tires on my '26 touring.
I think 21 inch tires on demountable rims with wood wheels was the most common combination in '25,26 and '27.
Disc wheels used them too.
Ford didn't manufacture a 30 x 3 demountable - and only non-starter cars of that ear had 30 x 3 (24") fronts & 30 x 3.5 (23") rears. "Demountables" were 30 x 3.5 all the way around.
21" rims were demountable but also a "split rim" as Keith alluded to above.
"Era" - you guys know what I meant !
I have some T wheels that use a "demountable" lock ring style rim in 21" size. They use a "loose lug" attachment and were made by "USW". Yes they are era after market. Hayes of course made 21" wire wheels with demountable "split" style rims that were sold by Ford dealers and were listed in the '26 T parts book.
These are 26-27 21'' Ford demountable rims. Very commonly used with 440/450 X 21'' tires.
There appears to be some confusion above between "demountable" and "non-demountable". Not entirely "non-understandable" as the terms are archaic and even spell-check doesn't like them.
21 inch demountable rims, wheels, and tires are common, having been used by Ford from 1925 (optional) through 1927 model year (sort of standard depending upon which original reference that you look at).
30 X 3 1/2 are common in both demountable and non-demountable variations. 30X3 were used (on model T Fords) only on front wheels and only on "non-demountable" tire wheels. 30 X 3 1/2 were used on all four wheels on all USA production demountable rim wheel Fords from 1919 through 1924, and Canadian production non-demountable tire wheels from about 1913.
I think I had better stop now. There are quite a few more detail variations, but my head is starting to hurt. And I suspect most readers have gone glassy-eyed already.
I hope I got that much right?
Drive carefully, and enjoy, W2
The century old definition of demountable is quite straight forward. It means that the tire comes off the vehicle fully inflated and thus you can carry a spare that is also fully inflated. Some Model T Fords used demountable rims ( can also be expressed as rim demountable wheels) to accomplish the job ( 30x3 1/2 and 21"). Trucks often have/had rims that came off the ends of the spokes of the wheels with clamps/lugs on the end of each spoke. Many brands of wire wheels ( Buffalo, House, Dayton, Pasco, etc.) have the wheel with tire come off the car, this was known as center demountable. I'll bet your modern car, SUV, or light truck has center demountables on it! Just undo the lug nuts and remove the inflated tire assembly.
If your rim looks like the one posted by Gary Hammond, they will fit, but if it has the rounded edge, it takes clincher tires size 30X3 1/2 The bead on the clincher tires is rounded but the bead on the 21" tire is flat.
Keep this stuff coming. I am learning more than I expected about tires, wheels, rims and even spokes.
Today, I'm going to start sanding the clear finish a former owner spent days on 60 years ago. Back then, they painted horseless carriages all kinds of carnival colors. I guess they felt it made them look snappy. I'm going to try to return my car to the factory look, with painted wheels. And yes, the wheels are non demountable!
Tires measured as an outside diameter are HIGH pressure tires 60 psi or up
Tires measured as an inside diameter are LOW pressure tires 35 psi or lower,
Not to be mixed
When the first 21" wheels came out for the improved Ford the tires were designated 29x4.40. When they got to the Model A they were called 30x4.50. Anybody know when they started designating them 21x4.50?
Paul, Ford also sent cars all over the world, and some used 30x3 1/2 demountable straight sided rims and tires.
Larry, you devil you! Of course the wheels are demountable. How else are they put on the car? The rims may not be demountable though!
Allan from down under.