<B>Crash.net's Valencian GP blog: Sunday.</B>

Sunday pm - Rossi Justifies Bridgestone Move in Amazing Open-Air Conference

In a bizarre open-air press conference after his retirement at Valencia, Valentino Rossi justified his switch from Michelin to Bridgestone for 2008, and again criticised Yamaha for the lack of power this season in their YZR-M1 machine.

Standing between two Fiat-Yamaha trucks at the back of the pitboxes on the Ricardo Tormo circuit, Rossi said that Dani Pedrosa's dominant win on Michelins in the final MotoGP race of the season had not affected his opinion about his switch to the Japanese rubber.

"Tyres are about a matter of feeling and trust," he said. "And I have lost trust in Michelin over the last two years."

The 28-year-old Italian said that the tyre move was a challenge, but not as big a risk as when he jumped from Honda to Yamaha at the end of 2003 - and succeeded in winning back-to-back championships.

"I don't think I can win with Michelin," he said. "I think Michelin will be a lot better next year, and they will have a bigger budget, but it's not my problem. With Michelin you tell them what the problem is, but you can never get a good answer. With Yamaha you sit down and talk and they give you an answer."

As dusk fell over the paddock, Rossi also vented his frustration at the machine failure that saw him surrender second place in the championship to Dani Pedrosa.

"I thought I could finish 11th or 14th in the race," he said. "I was fairly quick, but then when I braked for the first corner I felt something block in the engine, and the rear wheel stopped. I pulled the clutch in and released it, but the feeling was different from the tyre, so I stopped.

"I didn't expect this to happen with this engine, because it's not the new engine with the pneumatic valves [which had let him down once before]. I am very disillusioned."

Despite suffering from the three fractures in his right wrist and little finger, and a harrowing weekend, Rossi then turned to the fans who were jostling journalists in the two-metre space between the trucks and began signing autographs.

The Doctor has suffered two cruel and frustrating years, but his appetite for putting on what he calls "the show" burns undimmed, and he remains the most charismatic figure in MotoGP racing.

Sunday pm - Britain Sinks to New GP Low

Chaz Davies' practice crash at Valencia on his Pramac Ducati robs him of the chance of scoring a solitary point in this afternoon's MotoGP race - a circumstance that says much about the sad state of British motorcycle racing today.

It means that this season will be the first since the world championships began in 1949 that no British rider has scored in the premier class, according to Martin Raines, MotoGP's official statistician.

Britain once dominated 500cc racing (the equivalent of MotoGP until 2002), providing 17 of the 29 champions until 1977, when Barry Sheene was our last hero. Since then we've hit the doldrums, and we're getting even worse.

Thank goodness for James Toseland, who had the guts to get out of British racing when he was 17, and will be repaid with a place in MotoGP in 2008 with the Yamaha Tech 3 lineup.

Unfortunately, we have no one big enough to fill his shoes in the World Superbike Championship that he's leaving, so the country that has provided seven of that series' title-holders won't be repeating those successes any time soon.

It's just so much safer staying with a comfy British Supersport ride...

Sunday am - Yamaha Rejects V4 and Pneumatic Valves for 2008

In its struggle to win back the MotoGP world championship, Yamaha will NOT build a V4 engine, will NOT adopt pneumatic valve gear, and will NOT copy Ducati's desmosdromic valve operation.

This extraordinary series of apparently negative decisions - which fly in the face of rival manufacturers' experiences - has been revealed at Valencia by Masao Furusawa, Yamaha's head of engineering.

Furusawa said that he has investigated alternatives for the YZR-M1, but will stick with an in-line four-cylinder layout, using traditional valve spring technology.

"We have made a lot of computer simulations of a V4 and we have found good and bad points," Furusawa said in a media presentation. Yamaha preferred the in-line four because it permits a more compact engine and a shorter wheelbase.

Furusawa admitted that valve springs had a ceiling of 19,000-20,000rpm. But he said: "Increasing the rpm increases the power, but at the same time you have more friction between the piston and the cylinder. And I don't think that over 20,000rpm is the way to go. I would like to make an engine that has lower rpm but good torque, one that makes a good 'conversation' between the rider and the tyre."

Yamaha has tested a pneumatic-valve engine this year, but Kouichi Tsuji, leader of the M1 project, said: "From the point of view of fuel efficiency and power, we have had no gain from it. If we find a benefit we would be ready to use it."

Kawasaki is currently proving that an in-line engine can match the V4s used by Ducati, Honda and Suzuki: in qualifying at Valencia Randy de Puniet was quickest through the speed trap at 300.8kph (186.796mph). But Valentino Rossi, the quickest Yamaha rider, hit only 293.5kph (182.263mph - 4.533mph slower).

Why is the Yamaha still lagging? "We are struggling to maintain horsepower and fuel efficiency," Furusawa admitted. "We always try to make a good engine, but the result isn't always the same as our plans."

Rossi and MotoGP newcomer James Toseland will be hoping that Yamaha can recover power parity with other manufacturers during winter testing prior to the 2008 season.

Sunday am - Michelin Accuses Riders and Dorna of 'Panic'

Michelin chief Jean-Philippe Weber has lashed out at riders who have criticised his tyres this year for using the rubber controversy as an excuse for their failure to beat new world champion Casey Stoner.

The French company has been the focus of criticism as Stoner and his Bridgestone-shod Marlboro Ducati have scored processional victories, and Dorna chief Carmelo Ezpeleta proposed at one stage that MotoGP might become a single-tyre series in 2008.

But, in an exclusive interview with Crash.net at Valencia, Weber said: "Riders, especially those on Michelin, have criticised the tyres rather than accept that Casey Stoner is an excellent rider. They were saying: 'It's the tyres, the tyres, the tyres.'

"The media, the riders, the organisers - everyone was affected by the pressure and started to say that it would be better to have one sole manufacturer."

Weber said that Michelin had suffered two particularly difficult races at mid-season - Laguna Seca and Brno - and Bridgestone one, at the Sachsenring. But he said that after Valentino Rossi bounced back to win in Portugal on Michelins, he was shocked when Dorna produced the single-tyre idea at Motegi.

"In mid-season the paddock panicked, and everyone started talking about tyres," Weber said.

Clearly furious at the way Michelin has born the brunt of the blame for some dull races this year, Weber pointed out that the MotoGP paddock had totally failed to take account of circumstances produced by the new 800cc bikes in 2007.

"The hierarchy of the manufacturers has completely changed," he said. "In 2006 Honda had a really competitive bike, and the Yamahas had better all-round performance than this year. Meanwhile this year the Suzukis and Kawasakis [both Bridgestone-shod] have improved."

Weber admitted that Michelin had experienced problems this year. New tyre rules have prevented them from making overnight "specials" for European races in their Clermont Ferrand factory. They had been used to producing tyres with a high level of performance over a narrow range of operating conditions, but this year they have to make more versatile tyres - a philosophy that they have now embraced totally.

What does he think of Rossi's decision to abandon Michelin for Bridgestone next year? "We have a saying in France, On sait ce qu'on perd, mais pas ce qu'on gagne [you know what you will lose, but you don't know what you might win]. We'll see next year.

"Valentino seems to need a new challenge. It's something that he has decided in his head, and I think that neither Yamaha nor Michelin can make him change his mind. Time will tell."

Now, Weber suggested, the tyre situation is calm again, and there have been two races where everything's been much more serene. Meanwhile, he pledged that Michelin will "work, innovate, and continue to accelerate development. We will be better organised. We will continue to develop the new 16in rear tyre. It has pluses and minuses, but if the riders want it, we will offer it to them."

A factory that has been involved in grand prix racing since 1973, and won 15 consecutive premier-class world championships from 1992-2006 was never going to fold up after one wobbly season.

Sunday am - Dunlop to Quit MotoGP

Dunlop will be forced out of MotoGP in 2008 - even though their Yamaha Tech 3 riders Sylvain Guintoli and Makoto Tamada have qualified for the second row in fifth and sixth places for this weekend's Valencian round.

"That is a competitive qualifying performance," Dunlop tyre chief Jeremy Ferguson said proudly. "Week in, week out, we're improving. But everyone is under short-term pressure for immediate results from sponsors and riders."

The Tech 3 operation will switch to Michelin tyres for new riders James Toseland and Colin Edwards next year, and Ferguson has been unable to find a successor team.

Dunlop have found it tough competing against Michelin and Bridgestone in their two years in the white-hot MotoGP scene. But Guintoli gave them a fourth place in Japan this year, which compares well with Bridgestone's best finish of third place after two years in the series in 2003.

It took the Japanese manufacturer three seasons to record a race win, and it's been a six-year battle for them to wrest the championship away from Michelin.

Ferguson said the small quantity of bikes on the grid - just 19 regular starters this year - makes it hard for a new tyre entrant to attract support.

"We have 70 riders at a grand prix who sometimes get overlooked," Ferguson said, referring to Dunlop's supply of tyres for riders in the 125 and 250cc classes.