Joe Murray was Kona’s designer in the early days. He was famous for his prodigious racing exploits in the mid 80s, but had been designing components for a while. He was involved with Marin from its inception and came into contact with Kona’s founders as their company was Marin’s distributor. His initial bike designs for The Bicycle Group (1987/88) were sold under the Cascade brand, named after the West Coast mountain range. Fortunately, an ownership dispute forced Dan Gerhard and Jake Heilbron to choose the name Kona instead from 1988. It turned out to be quite a successful decision.
As Kona became known for sloping top tube designs, it seems odd that the Cascade precursors had short head tubes and flat top tubes. But Rocky Mountain had flat top tubes too until 1986, and from 1987 went through a similar transformation to sloping top tubes. Maybe Paul Brodie was the common factor. He built sloping top tube frames when he worked at Rocky Mountain, then went off to found Brodie Bikes and worked with Joe Murray for TBG on establishing Kona. It seems likely the sloping top tube design for the 1988 Kona range may have been a joint effort between them.
After Brodie’s involvement ended, Joe Murray continued developing the design. Longer seat tube extensions increased top tube slope and the 1990 Explosif used the new Tange Prestige Concept heat-treated cromoly, sporting oval top and down tubes tapering from thinner at the rear to fatter at the front – a more expensive tubeset, using shaping to give strength and stiffness in the plane in which it is most needed. Then shorter seat tubes and head tubes and a steeper head tube angle for 1993 were a first step towards assimilating to suspension forks, while the Explosif used the latest development of Tange Prestige, Tange Ultimate.
The 1994 frames were ‘suspension-adjusted’ – i.e., had a 71 degree head angle with a new 41cm P2 fork (1993 Konas had that angle with a 39cm P2). 41cm approximated the length of a part-compressed suspension fork with a rider on board. Revising the frames and forks in that way, Joe made sure that fitting suspension didn’t slacken off the head angle and spoil the sharp steering for which Konas were valued.
Having designed the 1994 range, with suspension-adjusted frames and the first Kona aluminium frames, Joe Murray left Kona in 1993. It is perhaps a mark of Kona’s continuing respect for Joe and the value that they placed on his part in their heritage that they didn’t change the basic hardtail frame geometry again for many years, not until well into the 21st century.
So the 1994 Explosif was the first suspension-adjusted Explosif, but also the last designed by Joe Murray and the last of the Tange Prestige Explosifs. The subsequent Columbus Max ones are great frames, but to some the original Prestige Explosifs are the real classics.