This steel Kharkov derailleur is a derivative of a Campagnolo Record, but it has its own speck of originality. The cable pulls from one parallelogram plate to the other (neither of the knuckles is involved). Both adjustment screws are mounted on the front knuckle (where they may, unfortunately, gather dirt).
There is a crudeness to it - it is heavy as sin, the knuckle castings are thick and rough, the bolts and fittings are imprecise etc. etc.. However there is also a sense of engineering principles at work - it is not pure imitation - something that cannot be said of more prestigious products from Zeus (in the west) and Tectoron (in the Eastern Bloc).
Like the T34 tanks for which Kharkov is rightly famous in so many ways, this derailleur might be crude but might also prove surprisingly effective.
I think this example is a later version of Kharkov’s steel model - with barely visible embossing of the logo on the outer parallelogram plate and plastic pulley wheels branded KVZ (or XB3 if you prefer!).
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