 In 1937 the valve gear became fully enclosed on the 500 cc models, but finances were bad and Rudge was bought by EMI, and production was interrupted, being moved to Hayes, Hillingdon in Middlesex.A 250 cc two-valve Sports was released in 1938, and for early 1939 the Ulster had an RR50 aluminium cylinder head.Production ceased in December 1939, to convert to radar production for the war effort.