The Woods Valve

I always thought there were just two types of bike valves - Presta and Schrader. The other day I needed to pump up the tyres on my Cambodian single speed mean machine, and I decided to pick up a pump instead of using the street corner repair guys. Anyway, a quick look at the valves on my bike left me a bit confused. I'd never seen anything like these before. Our guard, Vuthy, saw me looking perplexed and came over to help with his foot pump. Watching him I really couldn't understand how the valve worked. So, a bit of internet research later and i'd established they're called the "Woods" or "Dunlop" valve. Supposedly they were very popular in England back in the day (John Boyd Dunlop invented them and the pneumatic tyre which were fitted to J.K. Starley's chain-driven safety bicycle in 1888 - basically the first modern bicycle). Woods valves are apparently still the dominant valve in Japan, the Netherlands, Germany, and most of the developing world.

So, armed with this information off I went to the stationary shop (which I knew from previous experience sells a lot more than stationary) and I buy a pump which at least has an adapter that looks similar to Vuthy's. They're very simple valves - the whole core can be removed and replaced - and rely on a rubber sleeve over the core to make the seal, and a locking nut to keep it in place. It's hard to get much pressure into them because of this. In theory, you can just attach the pump and inflate (there's a tiny hole in the core which forces air through but the rubber sleeve prevents it escaping). In practise I found it a little easier to release the locking nut a little bit to get the air in.

I think other expats here must get confused by these too because every time I go down to pump up my tyres, Vuthy runs over to give me a hand.

http://en.wikipedia.org/wiki/Dunlop_valve#Dunlop_.28or_Woods.29
http://www.sheldonbrown.com/gloss_w.html#woods
http://www.sheldonbrown.com/gloss_dr-z.html#dunlop