Daytona Dilemma: Roberts Vs Sheene

Roberts and Sheene first raced towards one another at Daytona in 1974 – and over the subsequent decade they went head-to-head greater than 100 instances. VJMC’s Steve Cooper seems again…

Regardless of ultimately profitable 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 readily available however the bike failed in the course of the race. Graeme Crosby introduced the bacon dwelling for Yamaha however on a TZ750 – a machine Yamaha had formally stopped constructing, promoting and operating again in 1979!

The consequence 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 had been its shortcomings obvious on the essential GPs throughout Europe, but additionally 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 look like a knee-jerk response to only one race consequence however the significance of profitable 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 previous, 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 capable of ship the very 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 just about 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 effectively… 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 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 similar time. Heated exchanges together with his mechanics and the Dunlop tyre individuals lastly uncovered the issue. The entrance tyre was discovered to be some 50% down on strain post-testing regardless of being appropriate initially. It was found the Dunlop boys had been pushing their tyre temperature probes into the rubber too deeply, successfully creating micro-punctures. Pink faces and smug grins as acceptable, the problems had been addressed, and so on.

Roberts was adopted dwelling by teammate Eddie Lawson on a Yamaha first and second double, thereby restoring household honour. A 12 months later Roberts ended up combating 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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