MTFCA Forum

Creating a WWI ambulance that will be a static display vehicle only. Maybe on and off a trailer or at a car show or military vehicle display, but never actually driven. I need new tubes and got sticker shock for 4.50x21 center valve stem tubes. Almost $30 a tube. But a metric equivilent of a 120/80x21 motorcycle tube is as low as $12. As long as they hold air, a tube is a tube, correct? I'm not talking about sidewall flex, butyl rubber, dot ratings, etc. Just to hold air. And, the $12 tube even has a metal valve stem which I like for the military appearance.

Anyone done this? Any thing I need to worry about?

Cycle tube stems are much shorter. They may not be long enough to air up when installed.

There are some valve stem exstentions that are made for modern tires so a hub cap doesn't block the valve stem but I don't know if they would fit thru the hole in the rim if need be to get up high enough.
Sticker shock is becoming all to common in all my hobby's

Hey there Mack Cole!
I recently had a problem with a broken valve stem for my 1927 Paige. Looking for a quick easy fix I tried to use new valve stem extensions like I had used some years ago. Nothing I could get locally would work. What I used years ago allowed me to remove the valve core from the innertube, and used a valve core in the extension. Those years ago sealed fine onto the tube's valve stem, and worked fine. The only (several from several stores!) ones I could find locally (recently) required the tube's core remain in place as the extension would not seat airtight onto the tube's stem (that I could have fixed?). But because they did not use a real valve core themselves, the lousy complicated mess they used added so much restriction that my 100 psi air compressor could not force air through the double valves (in a timely manner) and without the stem's valve in place the extension's valve leaked all the air out in a couple hours.

Maybe where you are good extensions are still available? The good ones I used to have and used all of them, were metal (brass) and used a real valve stem valve that could be removed and really worked, but could be replaced if needed.

There are machined brass valve extensions available. They are often used on trucks. The best ones seal on the old stem, and have the valve core in the extension so they work just like a normal valve stem. Others have an internal mechanism which is pushed down by the head of the inflating connection, to push the valve core that is in the original stem down to pass air. Stay away from cheap plastic rubbish extensions.
The bad news is the machined brass extensions will likely be more expensive than the motorcycle tube on to which you want them to fit. I salt them away whenever I find them at a swap meet.

Allan from down under.

I always wanted to know if it is possible to find a motorcycle tire that would fit on a T. It bothers me the monopoly of the market.

Great input, guys. So, what I'm hearing is that no issues with the tubes other than the valve stem, so if I can work out the extensions or a longer valve stem on these tubes, I should be OK.
On my WWII military jeeps we look for a TR15 valve stem as that is the right diameter and height to fit wheel holes and stem protectors. Is there a valve stem reference number that I am looking for to insure coming through the demountable rim? Or, should I just measure the old ones and make sure I get that length? What about the wheel hole? Anything on the motorcycle tubes that would make them too large to fit the rim hole?
I presume if the valve stem itself is too narrow and looks off coming through the rim hole, I can do something with a washer to fill the gap.

The vendor specializes in cycle tubes and tires, so I will ask them about valve stem options and extension options. I am familiar with the cheap plastic ones, but brass, sealed ones seem a much better option for my military appearance.

Now they are selling Mountain bikes and Electric bikes with about the same size tires.

I'm not sure of the size, valve stem length, or center location.

These are actually for cars, but at $18 instead of $28, I think I'll give them a try. Appears that a TR135 valve stem is what works for Model A wire wheels, and that is what these have.

https://lucasclassictires.com/tires/440 ... stem-tube/

signsup wrote: ↑

Sat Jan 13, 2024 9:09 pm

These are actually for cars, but at $18 instead of $28, I think I'll give them a try. Appears that a TR135 valve stem is what works for Model A wire wheels, and that is what these have.

https://lucasclassictires.com/tires/440 ... stem-tube/

If you are using on wire wheels the short stem wont be a problem.
You could cut the stems off & use period schrader stems.

I seen a T speedster with what looked like motorcycle tires on it they looked real small compaired to 450/475 x 21 tires.
Craig.

I'm going from memory, but I think I got a correct size motorcycle knobby tire for a WWI light patrol vehicle project I did years ago and there was a big difference in the sidewall width and the tread width and it looked pretty funky so I gave up on that. Also a big difference in the side wall construction from motorcycle tires, auto tires, and trailer tires. Also, what steered me away was some horror stories about car accidents using the wrong tires and the insurance companies not honoring claims because of the use of incorrect tires.
Tubes, I think should be OK from that point of view, and, as I said in the OP, this will be a static display vehicle.
I need to measure the hole size in the demountable rims unless someone knows it already to make sure the diameter of this valve stem will be correct.

So, when I mentioned sticker shock in my OP, here is what I'm looking at. Just FYI in case some guys are needing tubes and haven't purchased them in a while. And, I know I'm selecting some for appearance only for a static display, but if I go with metal valve stems and the metal dust covers as a package set from Lang's and use their recommended flaps, I'm looking at over $750 plus sales tax plus shipping for five inner tubes and flaps.

Ouch!

Robert, look on line for brass tube extensions. I see 2" ones lasted for $3 each or a set of 4 for $20, and that may be AU$!
Ditch the heavy flaps and save another $250. Use rim liners. You can cut them from an opened up bicycle tube, at a cost of AU$8 each. This makes a cost of just AU$11 per wheel over your tyre cost. If you want to hide the valve stem, period Dill stem covers with the built in sliding thread inserts will fit nicely.

Hope this helps.
Allan from down under.

This is waht I did on my 1915 War Wagon tires and wheels. Used the 2" rubber valve stem but covered them up with a brass rifle bullet casing cut off at the bottom. Selected one that fit the threaded part of the valve stem perfectly and the cap kep everything in place. Will probably go this route again but not paint the rims galvanized or aluminum but keep everything OD green. The ambulance will be a lighter yellow shade of lusterless OD green and I am leaning towards painting the wheels a darker shade of an OD gloss or semi gloss green just to break up the shades. In reality, no color standards for the military in WWI and parts supplied from various vendors would all be slightly different in shade.