Jóka derailleurs were produced by the Józef Kalinowski company based in Ruda Śląska in southern Poland. In a fine tradition, the word Jóka is made up from the first two letters of the founder’s forename and surname.

The company appears to no longer exist, with the most recent sighting being a credit report of some kind in April 1992. A Jóka derailleur featuring both adjustment screws in the rear knuckle (like a Jóka (2nd style)) is shown in a 1988 Romet instruction book (as a Juka) and a 1989? Romet instruction book (as a Jóka).

While Romet products still evoke a modicum of nostalgia amongst Polish cycle mechanics, Jóka derailleurs are universally reviled. Disgusted sneers are usually accompanied by a barbed comment about the quality of the plastic. Ever the champion of the underdog, I rather like them.

As an aside, a correspondent tells me that Ruda Śląska is notable on two counts:

• firstly, close by is the site of the Zgoda Labour Camp, one of those incredibly confusing and tragic places that litter the 20th century history of Central Europe. Zgoda started life as a Nazi labour camp associated with the infamous Auschwitz concentration camps, part of the ruthless machine that the Nazis used to murder huge numbers of Jews and others. After the Nazis were driven out of Poland, the Communist authorities took the camp over, and used it to inter Nazis and suspected Nazi sympathisers. They installed Colonel Salomon Morel, a Polish, Jewish, ex-partisan as the camp commander. In 1992 Salomon Morel emigrated to Israel, only for the Polish authorities to try to extradite him back to Poland to face charges of war crimes relating to the many deaths and widespread torture of inmates at the camp. Israel did not allow him to be extradited.
• secondly, Ruda Śląska is the largest population centre in Poland never to have been visited by Lech Wałęsa.

What can I say?