Daytona Dilemma: Roberts Vs Sheene

Roberts and Sheene first raced in opposition to one another at Daytona in 1974 – and over the following decade they went head-to-head greater than 100 occasions. VJMC’s Steve Cooper appears again…

Regardless of ultimately successful the 1982 Daytona occasion for the eleventh time, the triumph was bittersweet for Yamaha. Kenny Roberts supposedly was the favorite on the OW60 that had some 156bhp available however the bike failed throughout the race. Graeme Crosby introduced the bacon house for Yamaha however on a TZ750 – a machine Yamaha had formally stopped constructing, promoting and operating again in 1979!

The outcome ought to have been trigger for celebration however, in actuality, it simply underlined the truth that the TZ500/YZR500/sq. 4, half-litre, OW60 was failing to ship. Not solely have been its shortcomings obvious on the essential GPs throughout Europe, but in addition the bike had bombed out at Daytona which was a key gross sales instrument within the essential America market – motion was wanted ASAP.

It would seem to be a knee-jerk response to only one race outcome however the significance of successful the Daytona race can’t be over-emphasised. Taking first place in Florida had a direct, tangible, impact on USA gross sales for the forthcoming 12 months. Pushing the sq. 4 idea to absolutely the restrict, Yamaha’s boffins ship the OW69. If the outdated, in-line TZ750 had been The Beast, then the brand new bike was The Monster. Taking the bore out to 64 millimetres with the retained 54 millimetre stroke gave 695cc of brutal energy. The endeavor demanded revisions and strengthening of heads, cylinders, crankcases, crank, pistons and exhausts. Though ‘solely’ drawn as much as ship 150bhp, the brand new motor was in a position to ship the important low and mid-range energy the five hundred OW60 was missing. For the needs of verification the race staff additionally constructed a fully-tuned OW69 motor which was able to producing some 175 horses. Perversely and regardless of all the problems with the donor chassis, the OW69 ran the OW60’s in nearly unaltered format!

Within the run-up to the 83 Daytona the OW69 had been shaken down at Laguna Seca the place, it transpired, the bike solely did one factor nicely… go quick. KR’s language merely couldn’t be reiterated in well mannered firm however the jist of it was that the OW60 was a pussycat as compared. At Daytona, Roberts was positively incandescent when the bike wouldn’t flip in because it was anticipated to AND was discovered to be pushing the entrance finish on the identical time. Heated exchanges along with his mechanics and the Dunlop tyre folks lastly uncovered the issue. The entrance tyre was discovered to be some 50% down on stress post-testing regardless of being right initially. It was found the Dunlop boys had been pushing their tyre temperature probes into the rubber too deeply, successfully creating micro-punctures. Purple faces and smug grins as applicable, the problems have been addressed, and so forth.

Roberts was adopted house by teammate Eddie Lawson on a Yamaha first and second double, thereby restoring household honour. A 12 months later Roberts ended up preventing with Freddie Spencer mounted on the Honda NSR500. Teammate Lawson was plagued with tyre put on issues. Roberts received from Spencer and introduced he wouldn’t race at Daytona once more. The 50mph disparity between the quickest and slowest was creating large security considerations for the highest riders.

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