MTFCA Forum

Recently purchased from vendors. All marked 440/450-21. Same air pressure on all. All different. Am amazed at the disparity.

Hard to tell in the photos. But the seam patterns and rubber texture seem to be different on all three. They could still be from the same supplier, and even the same manufacturer. (Maybe?) However almost certainly from different batch runs.
Innertubes without a tire to restrain them, air pressure doesn't mean much. The rubber stretches at a very low pressure, and different qualities of the rubber have some stretching a lot more than other.
Folds in the innertubes exposed to the air often crack around the outer edges of the fold (due to atmospheric contamination, and exposure to UV). I have seen new innertubes go bad in less than two years while sitting in the dark back clean area of the shop. It is caused by the stretched outer edge of the fold stretching the rubber and making it more vulnerable to the air contaminants. For that reason, I usually keep spare innertubes aired up to prevent folding. Spare innertubes kept that way in the dark makes them last longer. Inside a spare tire is even better.
The point of that previous paragraph is that the innertube rubber stretches easily, and a lot. A given "pressure" of air inside will make some innertubes stretch to a very large size, and the same pressure in a different innertube likely stretch only a very little.

For many years, I had a spare innertube that I aired up for storage. Three quarters of the way around the tube hardly stretched at all. To make the tube barely firm on that three quarters (barely four inches diameter), the small amount of pressure required had the other quarter stretched out to about ten inches diameter. The stretching quality of the rubber in the one innertube varied that much!

Before I pumped in 5 psi, the tubes were similarly disparate in physical size when recently received new out of the package.

I'd say this is a perfect indication of the quality control exercised in the production of tyres and tubes today, if these are the same brand from the same supplier,{not the vendor] Would these be acceptable to motorcyclists? I think not.
Allan from down under.

What are the brands of the tubes?

I have come across a number of tubes from one of the national parts suppliers that to me looked like the manufacture stamped 30 X 3.5 on tubes they had on hand to fill an order. Those tubes being way small in the overall diameter to really be correct, you had to really fight to keep them inside the tire casing when installing.

There is another alternative, along the lines of the more expensive Blockley tubes. Michelin offers a metric equivalent at about the same cost as Blockleys. Both are really thick. Next time I fit either i will weigh them to make a comparison with a cheap version.

Both have the larger threaded brass stems which take all the usual nuts, dust caps etc. The blockley stems are moulded into the tube. The Michelin stem threads onto a base which is moulded into the tube.

You will pay more for a quality item. You will probably pay more again when the new beautiful tariff regime kicks in.

Allan from down under.

"jsaylor » Fri Apr 11, 2025 11:59 am
What are the brands of the tubes?"

No brand markings just the size marking. These were purchased recently from current Model T vendors who are not at fault for the disparity. I suspect the tubes are foreign made. I have used Hartford tubes, very good quality.

If the vendors don't know who makes the tubes they supply, where does that us? The last ones I ordered from Langs, 4.50x21 were marked Custom Classic. They seemed a little thin, but are holding air. Who sells Hartford tubes?

I’ve been getting Hartford tubes from Coker Tires. I’m waiting for an order delivery that includes a couple of 30x3 tubes right now.

Keep cranking’
Eric

Eric is correct. Coker sells Hartford. I suspect others may also, but I haven't asked around. I started avoiding Custom Classic because of the problem I had with them splitting. That was years ago, and the split-prone ones may no longer be in the supply chain. I have no reason to try them again as long as the Hartfords are good enough.

As far as I know all tubes sold with metal stems these days have the "wrong" size stems, which are larger than the ones Ford used on the Model T. I don't see that as a big problem because so many of the available covers and nuts, original or new, fit them just fine. Yes, the stems and covers on my car are "too big". I lie awake all night worrying about that.