MTFCA Forum

I bought new rims and a set of blockly tires and tubes and have them all mounted up. The tubes have metal stems and my question is, do I need another nut to lock the stem to rim, or leave it float like a rubber stem?

There is another nut, called a rim nut. The valve dust cover screws onto the top of the rim nut. Originals are stamped from sheet metal and have a leather washer on the bottom so that they don't scratch the rim. Older cars came with round, knurled nuts. Later cars came with hex shaped rim nuts.

Current reproductions are solid and come with a rubber washer.

It is not necessary to fit a rim nut. It is one more thing to remember if you need to remove the rim and tyre for repair. If you use Dill dust covers, the nut is never required.

A secondary consideration may be that if your tyre is run underinflated, a lean on the valve stem will indicate this for you. If the stem is anchored with a rim nut, you will not know of the underinflation.

Allan from down under.

It all depends on how "correct" you want your car to appear. Blockley tubes come with threaded steel stems precisely so that you CAN affix the base nut that then carries the metal tube cover; looks "correct" even though it isn't entirely proper. While you can use one, you don't need a bridge washer underneath because the stems are permanently fused into the tube, the bridge washer and inner nut were screwed down to hold the base of the original style metal stem onto the tube, itself. While you likely bought Blockley because the tube rubber is twice as thick as anybody else's tubes, and well worth the few extra $$$$, you did get the threaded metal stems automatically, so use them. Your car would originally have carried the metal dust covers that entirely surrounds the stems, brass if early, nickel plated if later. The age difference is noted in a contribution above. It gives a nicer, more finished appearance, and is just that little bit more "correct". Model T parts houses may have the dust covered available, I bought a nice set of brass ones from Coker recently for a Buick, will fit the Model T, too. But, no, the metal stem covers and base washer are not required, you can leave the metal stems exposed, sort of like you not wearing any clothes on the way to work.

IMO, add the rim nut and add a dust cover.

The rim nut will maintain the metal stem straight, esp. if the tube gets under-inflated, as the stem could shift in the larger rim hole and could tear loose from the tube.

The problem is, even though Blockly is sort of doing us a favor, they are not. The tire valves are too large for a Model T. They don't want to change a thing, even though what they offer is incorrect. For me, I'll be happy to wait until an American tube manufacturer decides to help out.

Larry, I wouldn't hold my breath while you wait for an American company to make "correct" tubes. They stopped making them years ago.Why would they start up again to fill a small niche in the market? There's cheap junk tubes which don't hold air, there's thick Blockley tubes which do hold air and have threaded metal stems, and there's thick Michelin tubes with two piece valve stems. Perhaps you could persuade Michelin to modify their screw on stems to emulate the stems you want.

Allan from down under.