By Peter McLaren
Nicky Hayden still doesn't know which type of engine he'll be using at the 2008
MotoGP season opener, in Qatar on March 9, but suspects it could be last year's spring-valve design.
The two opening tests of the year - at Sepang and then Phillip Island - saw the lone Repsol Honda rider present, following
Dani Pedrosa's hand injury, swapping between the new-for-2008 pneumatic-valve engine, which he hopes to race with, and the 'standard' spring-valve design from 2007.
The problem with the pneumatic-valve powerplant is that it is yet to match the performance of last year's engine - prompting Honda to fit the old spring-valve design into the new chassis, a combination that has been getting more and more track time.
Indeed, on his final pre-season visit to Sepang this week, Hayden rode only with the spring-valve engine, allowing him to concentrate on chassis and tyre development.
But the '07 engine/'08 chassis set-up is also far from ideal. The spring-valve, although better than the pneumatic engine, has still lost ground compared with the latest engines from Honda's leading rivals. Handling is also compromised, since the '08 RC212V chassis was designed specifically for use with the '08 (pneumatic-valve) engine.
"We didn't ride the pneumatic-valve engine at all this week. It's back in Japan and hopefully we'll see it again real soon, because that's what our potential is and obviously that's what this chassis is designed for," confirmed the 2006 MotoGP world champion, speaking exclusively to
Crash.net after concluding his Sepang schedule on Wednesday, a day earlier than his rivals.
Hayden, one of only nine riders at the final Sepang test, was second fastest to Fiat Yamaha's
Valentino Rossi on both days, but unable to match his own qualifying or race tyre best from the January test (also set with the spring-valve engine). Overall, Hayden was 0.428secs behind Rossi on one-lap Michelin rubber, but the deficit on race tyres was a more worrying 0.98secs.
