Hello
Have a look at the valves thread for the woods prob. Went to get my adapter and the bike shop also said change over to Schrader valves asap. May regret it but going to stick with what I've got for time being, but got adapter.
However do think it may be helpful if 50cycles changed to a more customer friendly inner tube/valve.
Ibby
The guy in the shop was dead right - where did these 'dinosaur' valves come from?
The Wood’s Valve.
I have been completely puzzled by the posting and counter posting on the subject of the “Wood’s Valve” (aka “Dunlop Valve”, etc). So much so that I believed it was something I had not come across before. I now find (courtesy of Sheldon Brown and the internet) that it was commonplace in earlier cycling history and was in use right up until the 1940’s and maybe even longer on Cheaper Bicycles (such as the Kalkhoff - ).
The air in a tube capped with a Wood’s Valve is retained by means of a small rubber tube forced over a ‘spike’ which has been bored halfway (or so) down its length and the bore exiting at the side of the ‘spike’. Thus, the pressure on the ‘small rubber tube’ by the air in the tube (tyre) prevents the escape of air from the tube through the valve (I won’t go into the other physical phenomena that helps retain the air). But this is theory: Wood’s Valves are notoriously less effective (in my experience) at keeping air in the tube at the correct pressure than say Schraeder or Presta. On my touring cycle, bespoke made in 1945, I opted for High Pressure Tyres and Tubes (Clinchers they were called) capable of withstanding 80 psi (or more) which makes for less rolling resistance and nice Presta Valves.
Now why anyone would wish to continue with or choose to adapt “Wood’s Valves” to accept a modern on-bike cycle pump puzzles me. Inner tubes are cheap enough and can be purchased with Presta or Schraeder – indeed procuring a tube fitted with a Wood’s Valve would be the hard way to go,
Then I had another thought. Why did Kalkhoff choose to have Wood’s Valves on their tubes? Were those tubes being sold off cheap by some museum of a manufacturer who had found a cache of them at the back of his storeroom when they took over a factory and adapted it to the production of Kalkhoffs?
If someone wishes to persist with Wood’s Valves I can advise that they are inflated by using a “screw in (to the pump) - screw on (to the valve)” connector which has the added advantage of flexibility. These pumps are quite capable of inflating a tyre & tube to 80+ psi BUT the flexible connector must be capable of withstanding the pressure to be generated otherwise they will simply “POP”.
Schraeder Valves may well fit the hole in the rim designed for the Wood's Valve - a little enlarging may be required.
Presta Valves are far too small to fill the hole.
Virtually no gap should be allowed between the valve and the hole: the tube will find its way there and "BANG"!!!
Peter
