Tire Tube

次回、新しい記事を日本語で投稿します。

It is hard to find NOS (new old stock) BE (Beaded Edge) tires from the 1950's, but it is even more difficult to find NOS tubes.

But as always "seek and you shall find" has paidoff.  I obtained a pair of NOS tubes and got them for next to nothing because the majority of the people out there are under the false impression that "old" is "no good".

As with nearly every part on bicycles from the 1950's, even the tire tubes bear the manufacturer's name, MITSUBOSHI TUBE, MITSUBOSHI BELTING LTD.  Note the grey patch at the base of the valve something you won't see on today's tubes.  If a manufacturer is going to go to this extent to put their name on a product, you know it has to be good.

The vale stem is a Woods valve stem (also known as a Dunlop valve stem).

There are basically three types of valve stems
1. Presta (French)
2. Schrader (US)
3. Woods or Dunlop (British)  This is actually the oldest type of valve stem, and still in use today in many countries (Japan, India, Russia, the Netherlands, Germany, Finland, Sweden, and developing countries).
When the Japanese began making bicycles they learned from the British.  Thus many of the British standards are reflected in old Japanese bicycles.
The metal piece at the bottom of the valve stem is known as the plate washer.  This is also something you won't find on today's bicycle tubes.

BE tires rarely get a puncture, as the beauty of these wonderful tires is that they completely envelope the tube to protect it. In fact, in the six years that I have been riding old bicycles, I have only had one puncture.  And I ride over 2,500 kilometers a year.

That said, however, with the Woods valves, as most of you already know, if the tire ever goes flat, the first thing to check is the rubber tube (seal) on the plunger (core).    If the rubber tube (seal) becomes old it may develop a crack causing a slow leak resulting in a flat.  The length of these rubber tubes is normally long enough so that they can be readjusted. Even replacement of the rubber tube itself takes less than three minutes and is a real timesaver compared to patching a tube.

The rubber seal must be positioned correctly above the neck and snug with the head of the plunger.  Since the rubber tube forms the seal inside the valve body, over time it typically wears at the neck (red arrow below).  Simply remove the rubber tube cut off the bad portion and refit. Or, remove and refit from the opposite end.