In 1948, when SHL production was reactivated in former Ludwików Steelworks, freshly renamed to Kieleckie Zakłady Wyrobów Metalowych ("Kielce Ironwork Factory") the factory construction office led by Jerzy Jankowski started to work on several sports models, for racing and rallying. One of them was RJ2. It was first time when in Polish motorcycle telescopic fork and plunger rear suspension were used. Very few of these machines were built.