Life at 23,000rpm

Honda might have accepted the need for two-stroke dirt bikes with the Elsinore, but they were still a four-stroke brand. So when Honda announced a return to grand prix racing in 1977 it would be with the NR500, a four-stroke V4 to fight the two-strokes. Gerald Davison ran the team, then head of Honda UK and successfully running RCBs in endurance races and at the TT. Fed up with the UJM jibe (see past post on Phil Schilling) Honda also decided to abandon the inline four and develop a range of V4s, starting with the NR. From the start there was conflict. Honda wanted to teach their band of aeronautical engineers about motorcycles. Davison wanted to win races. R&D chief – and aero engineer - Shoichiro Irimajiri’s solution was the same as it had always been: more revs. The team calculated a dizzy 23000rpm was needed for the targeted 130bhp. Much is made of the NR500’s oval pistons but the aerodynamics were as radical. The monocoque fairing, pannier radiators and 16” wheels all reduced frontal area. But beyond 16000rpm the motor overheated and the cam drive broke. At its debut Mick Grant’s NR500 blew when he wheelied because there were no sump baffles. Later Ron Haslam’s heroic lean angles left oil lines dry. The newbie engineers hadn’t realised motorcycles wheelied and leaned over. For 1981 Gerald Davison extended his management of the project on the condition fellow Englishman Ron Williams would provide a new chassis. A conventional tubular frame with eighteen inch wheels duly arrived for a redesigned engine that shed 20kg and reduced the V-angle from 100° to a more compact 90. There was now 132bhp at 19000rpm and a 24000rpm redline. Close but no cigar, so when the NS500 was handed to Freddie Spencer the NR was quietly retired. Was it a failure? Given Honda’s intention was to teach raw recruits about motorcycles perhaps it was a success. The subsequent NR750 racer was so fast the FIM banned anything but circular pistons. In 1991 F1 car racing did the same. It was a long, hard road but it taught Honda stuff so revolutionary it is now illegal in racing. Full story in Benzina 11 and my Honda V4 book. Plenty more photos available from A Herl - they’ve an eBay shop. The video of the late version NR500 being revved is only a glimpse into how wonderful they sounded at full chat

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