The MX4 was the last Greeves moto-cross bike to have the unique cast-alloy beam frame as this was replaced in 1969 by the all steel framed Griffon. Two years of testing saw this larger capacity Challenger introduced in 1967 after the FIM had ruled that the 500 class had to be at least 351cc as previous models had used over-bored 250cc models
The new ‘big bore’ 362cc had a lengthened frame for improved stability and new new conical alloy hubs. Built in relatively small numbers good examples don’t come to the market often and are highly sort after by riders wanting to compete in classic moto-cross events. This example was previously restored and has been unused as part of a private collection for some time. A very original example it remains in very good condition.