Ben Bostrom quickest at Valencia test.

A disappointing end to an otherwise fascinating first day of testing at Valencia saw the time clock run out with all the Superbike riders long gone. A persistent rainshower just after the beginning of the afternoon session, which had already been red-flagged and stopped, ended all the riders' chances to improve their lap times, making fast starter Ben Bostrom the quickest rider on the opening day.

His time of 1:36.438 was a whisker ahead of Troy Corser, and the top four riders, were insider the 2000 season's Superpole time.

Bostrom, running his new L&M sponsorship colours on track for the first time, gave his new backers instant reasons to smile, running fast and assured laps from the outset.

With great experience of running at Valencia, Bostrom made the most of his more favoured Dunlop tyres, although all the riders were forced to use softer compounds to overcome cold track temperatures.

The proven master of Valencia, having won here last year, is Troy Corser, and his time of 1:36.449 ran Bostom close, as the Aprilia rider strove to maintain his dominance.

Fastest of the WSB new boys was Tadayuki Okada, who has declared himself back to near fitness - and proved it - with his 1:36.476.

Troy Baylis was fourth quickest on his Ducati, running Michelin tyres, and put in a whopping 50 laps, more than any other rider could manage in the morning session.

A great performance from Alessandro Antonello delivered him an excellent fifth place, with the regular Aprilia test rider taking his outwardly scruffy RSV well ahead of many bigger names.

Reigning World Champion Colin Edwards was slightly detuned by a crash, which comprehensively damaged his machine, losing the front at the same corner the previous champion Carl Fogarty did during testing in 2000. Sixth fastest, 0.421 slower than his fellow American Bostrom was his best mark of the day.

Sensation of the recent Kyalami tests, Neil Hodgson, could only mange seventh fastest this time-out. Although once more he had the right to call himself top privateer, taking his GSE Ducati to seventh.

The fastest Kawasaki rider, Gregorio Lavilla, was on home ground at Valencia, and the Spaniard overcame bad memories of his 2000 Valencia experiences when he broke a wrist in pre-season testing.

Happy with his performance, and also on his home ground, was young Ducati firebrand, Ruben Xaus, ninth fastest on the time sheets.