/ stories  

  The Bicycle Tire  


I have been riding bicycles, fixing flats and putting air in tires for many years but I have to admit that Bobbie’s Japanese bicycle tire valves baffled me for awhile.  Bobbie had asked me to check her tires.  “I think they’re a little low,” she said.  Before I was finished I managed to completely deflate the front tire and blow up the rear tire.

The valve design is a picture of simplicity.  The center of the valve is very similar to the needle used to inflate a ball.  A heat shrink type of material is slid over the needle to block air flow.  All of this is held in place by a threaded cap and a dust cover is screwed on last.  The idea is simple; apply air at a greater pressure than what is in the tire and the shrink material moves away from the holes and air is allowed in.  Once the pressure is removed then the air pressure in the tire forces the shrink material tight against the needle and the air cannot escape. Unfortunately I removed the restraining cap along with the dust cover.  Not immediately recognizing what I was looking at I touched the needle and wiggled it.  The last I saw of it was during it’s trajectory over the house.  All I could say was, “You’re right honey.  Your front tire is a little low.”  Actually it was completely flat.  It was airless and I was clueless.  After a trip to Cainz (a dandy little store, sort of like a Target on steroids) for a new valve and then to the gas station for air and the front tire was ready to go back on the bike.   The young attendant at the gas station probably thinks I’m totally incompetent.

But you know that back tire looks a little low too.  So back to Cainz I go to get a hand tire pump with the special adapter for bicycle tires.   Back home I attached the adapter and begin to inflate.  If you haven’t figured it out yet the one problem with this valve design is that you can’t gauge the tire pressure.  It has to be done by “feel”.  Carefully I would push the pump handle down and then I would squeeze the tire, comparing it to the front.  After awhile I said, “looks good, honey you’re back on the road.”  However the sentence was punctuated with a loud ka-boom and the rear tire was lifeless.  This was the last thing I needed.  Attached to the rear axle are: the kick stand, a completely enclosed chain guard, the fender, the basket, the brake cable to a brake assembly in the hub and probably some other stuff.  I had seen several elderly Japanese women riding bicycles with the rear tire completely flat.  Now I know why.  Back to Cainz, this time for an inner tube.  Eventually with everything re-assembled and air in the tire I presented the newly shod bike to Bobbie, and then I got the hell outa there. - Chas