Following his hat-trick of wins in Japan, South Africa and Spain, Rossi suffered his first defeat of 2001 at last month's French GP. Then two weeks ago he crashed out of second place on the penultimate corner of the Italian GP. As a result his points lead has shrunk from a gaping 34 points, after Le Mans, to just 21 points. The soaking Mugello race also tightened the overall championship situation, Alex Barros (West Honda Pons NSR500) taking his first victory of the year to move into fifth, just 31 points down on Rossi, while team-mate Loris Capirossi (West Honda Pons NSR500) took second to move into third overall, just behind Max Biaggi (Yamaha).

Of course, Rossi isn't the kind of man to panic. He may only be 22-years old but he's entirely used to the pressures of racing for World Championships. In 1997 he took his first world title at the age of just 18, conquering the 125 class at his second attempt. Two years later he wore the 250 crown after dominating his second year in the quarter-litre class. Now he's in his second 500 season, fully aware of what he must do to claim the premier 500 title.

"I've lost some points to the other guys at the last two races but I still have a good lead," he says. "The conditions in the rain at Mugello race were so bad, and in that kind of situation it's easier than usual to make a little mistake. I crashed because I touched a white line, but I couldn't even see the line!"

Rossi rode his first-ever wet 500 race at Catalunya last year and fared much better. He finished a delighted third but would prefer a return to dry weather this weekend. "Last year we had far too much rain and I just hope Mugello wasn't the start of another wet summer, even though I have to say I enjoy racing my 500 in the rain more than I enjoyed 250s and 125s on wet tracks. The Honda has excellent torque and you can enjoy yourself playing with wheelspin. But I like Catalunya very, very much, so I want it to be dry."

Rossi has an enviable record at the Barcelona circuit - having won three out of his last four races there, the 125 GP in 1997 and the 1998 and 1999 250 GPs - but will have particularly serious rivalry this weekend from Barros and Capirossi. The Brazilian and Italian come to Catalunya riding on a high after scoring a first-ever one-two for Sito Pons' team at Mugello, and aiming for a repeat performance at their team's home track.

Max Biaggi goes into the Marlboro Catalan GP 21 points shy of World Championship leader Valentino Rossi Honda and aiming to take another bite out of his compatriot’s series lead. The Marlboro Yamaha Team ace has been the highest-scoring rider at the past two Grands Prix, scoring a win at May’s French GP and a third place in Italy two weeks ago, so he has the momentum to home in on Rossi.

Biaggi started his 2001 season in brilliant form in Japan, taking third behind winner Rossi and fellow YZR rider Garry McCoy. But his results slumped at the next two races in South Africa and Spain, where he was eighth and 11th, while Rossi continued his winning ways, securing a winning hat trick. In France Biaggi became the first man to inflict defeat upon Rossi, dominating the Le Mans race ahead of team-mate Checa.

"We’re getting closer to perfecting our bike set-up," says Biaggi. "Of course, we’ve still got some work to do but we’re not far away. It’s also good to be closer on points, though I think it’ll be two or three races before we can really start thinking about the championship situation; at the moment I’m just taking it race by race. Catalunya is one of my favourite tracks, I won four races there in my 250 days and we should have a good set-up for this weekend."

Biaggi spent two days at Catalunya in early March, lapping 0.8 seconds inside the lap record at 1m 46.0s, even though conditions weren’t ideal. "I was very satisfied with that test," adds the 29-year old who finished fifth in last year’s wet Catalan GP. "We concentrated on engine parts and suspension, and we had no vibration with either 16.5 or 17in rears. Of course, we’ve learned more since then, especially when we tested at Mugello last month."

Although Michelin’s 16.5in slick has been the most popular rear tyre over the last 12 months, Biaggi used a 17 at Mugello. He battled for the lead in the early laps but rain prevented the race going full distance in the dry. The event was restarted on a soaking track, the final result counted on aggregate time. "The rain was frustrating because we were very curious to see how the 17 would work over full distance," he adds. "We would’ve learned a lot about tyres but the weather has left us with a few question marks." 

Biaggi is due to stay at Catalunya next week to test his YZR500s and Yamaha’s all-new YZR-M1 four-stroke.

Based in nearby Castellbisbal, the West Honda Pons crew has high hopes of a strong showing on Sunday. "We know this circuit very well and like it too," says Barros, who holds the lap record (from 1998) and led last year's race from pole position. "I hope that Mugello was the start of my challenge for the championship. The points situation is still close and there are 11 races to go, I know I can fight for the crown if I keep performing to my best."

Sito Pons is also confident that his riders' title aspirations will take another step forward at Catalunya. "It is a very important race for us, because even though we have three races in Spain, this is our real 'home' GP," says Pons, who rode to the 1988 and 1989 250 titles on a Honda, before moving into team management in the early nineties. Since then the former architectural student has built up Honda's most successful SWS (Special Works Support) 500 team. Alex Crivillé won the outfit's first victory in 1992, and since then Pons riders have scored a further seven 500 successes, including Capirossi's historic Italian GP victory in 2000. That win was Honda's 140th in 500s, making the marque the most successful in the premier class.

Catalunya may be home ground for Pons' riders but it's also home tarmac for Alex Crivillé (Repsol YPF Honda NSR500). The 1999 500 king has twice tasted success at the circuit - at the 1995 European GP and the 1999 Catalan GP - and would dearly love to complete his return to form with another win on Sunday. Crivillé had a difficult title-defence season last year but is back on form and ready to win again. "I feel I've been riding as well as ever at the last three races," says Crivillé, born in nearby Seva. "We also have the bike going really well - the 2001 NSR500 is a great machine. But we'll have to work hard this weekend - Catalunya is similar to Mugello in that you need a perfect bike set-up, it's not the kind of track where you can just ride around a problem."

This weekend Carlos Checa contests the second of the year’s three Spanish-based GPs. Bike-crazy Spain currently hosts three GPs a season – the Spanish GP in May, this weekend’s Catalan GP and September’s Valencia GP.

Checa has experienced the highs and the lows of home races. Born near Barcelona, he won his maiden GP victory at Catalunya in September 1996 and his second GP success at Jarama, outside Madrid, in June 1998. But he had a torrid time at the Spanish GP six weeks ago, crashing heavily in qualifying and limping to 14th in the race.

"We have a lot of races in Spain so I’m used to the pressures of racing in front of my fans, it doesn’t have a great effect on me any more," he says. "What happened at Jerez was just unlucky. If everything goes well this weekend I know I can be up front again and I’ll be trying very hard to give the Spanish fans some more good memories."

Checa has already proved this year that he can run up front. He led last month’s French GP, eventually finishing second behind team-mate Max Biaggi after fighting off a strong challenge from Valentino Rossi Honda. And his lap times during his team’s pre-season tests at Catalunya including a best of 1m 46.5s suggest he should be on the pace again this weekend.

"We did some good work during those tests and I know and like the track, you always like places where you’ve won" he smiles. "I qualified on the front row last year and that will be my aim once again for Friday and Saturday. I know I can be competitive because we’ve made a lot of progress on bike set-up in recent months and I’ll be aiming to put what we’ve learned to good use. Most of all I hope the weather will be good on Sunday. It rained on race day last year and I crashed – the difference between grip and no grip in those conditions is very small."

Checa was similarly luckless at Mugello. Running well before the rain came, he was forced out of the restart with clutch-slip problems. "That was very disappointing for Carlos but he’s a very strong rider who knows how to bounce back from difficulties," says Marlboro Yamaha Team director Hiroya Atsumi. "He had a strong pre-season test at Catalunya, in fact he was strong everywhere we tested, but he’s had some really bad luck since the start of the season. It would be great to see him going well again, like he did at Le Mans."

Checa has had one other no-score this year – he missed April’s South African GP after a fall while training in Spain.

Kenny Roberts and Team Telefónica MoviStar Suzuki team-mate Sete Gibernau had a relatively disappointing start to the season, after what Roberts described as "Bad Karma" had interfered with their testing schedule.

Steady hard work has changed the picture, and over the last two races Roberts has been back where he belongs - up with the fast men, challenging for pole position and leading races.

The change has come about through steady development, maximising the new 2001 chassis and motor step by step in a continual programme of refinement.

The team was hoping for another significant step at Catalunya, the second of three visits this year to Spain. Earlier this year, team and technical adviser Warren Willing worked closely with Michelin to develop a new generation of 16.5-inch rear tyres. The French manufacturer hoped to have the tyres available for Catalunya.

Of course, they will be available to all Michelin users - almost the entire 500 class. But the tyres have been developed with and around the Suzuki, and by rider Roberts, which at least gives the team a head start.

Tyres are always a major issue, but have been even more so over recent races. The smaller rear rim size has been almost universal, until at the last race Roberts led a small-scale switch back to the 17-inch tyre, which helps corner speed, but until now has not been as good at endurance, hurting race average speeds. The latest tyres mean there is a third element to consider.

The Catalunya GP is the sixth round of the 16-race season, on the cusp of the first and second terms of a long season.

Kenny Roberts - "As far as the new tyres go, I don't know yet whether we will use them. We may stick with the 17-inch like at Mugello. I could get a good lap time with that, and then we'd see how it would last the race. Instead it rained and we didn't see anything. Literally!. Catalunya, like Mugello, has been one of the tracks we generally struggle at. There's some corners where you come off on the lazy part of the engine, where our bike isn't strong; and the long straightaway doesn't favour us either. I always go there expecting a tough weekend - but last year we won the race. That was due to the rain, and more rain this year would make all the difference. I'm hoping the weather will stay perfect until Sunday, like last year. I'll work to get on the front row, then try and win the race again."

Sete Gibernau - "At last our luck got better at Mugello. It was a very hard race in the conditions, but we got through it without any problems, and made the finish. After weekends where one little problem has come after another, that was a step in the right direction, to pay the team back for all their hard work. Now I'm back in Spain, at my home track. Nothing is different, though. I have no problem concentrating on the racing whatever the circumstances, and I always try to get the best possible result."

Crivillé's team-mate, 500 rookie Tohru Ukawa (Repsol YPF Honda NSR500) makes his 500 debut at Catalunya this weekend. Three times a podium finisher at the track in his 250 days, Ukawa knows this will be a challenging event. "It's not an easy track, even on a 250," says Ukawa. "We had a few problems at Mugello, so we'll be working very carefully to make sure we have a good set-up this time."

Catalunya should see the return of another 500 rookie, Leon Haslam (Shell Advance Racing Honda NSRV500), who missed the last two GPs after breaking a wrist during French GP practice.

Fans who flock to the Barcelona venue to cheer Checa and his fellow Spaniards will also be the first to experience the sights and sounds of GP racing’s new four-stroke era when Yamaha’s new YZR-M1 makes its public debut on Sunday morning in the hands of test rider Norihiko Fujiwara. The M1 is the first of the new generation four-strokes to run in public and the bike will stay on for private tests next week when Biaggi and Checa will ride the machine alongside Yamaha testers. The M1 will be a part of next year’s World Championship when big-bore four-strokes enter GPs for the first time in the sport’s history.

Catalunya is one of the more complex racetracks on the Grand Prix calendar, requiring painstaking work from both riders and engineers. The layout is dominated by long, rounded corners that require riders to spend a lot of time near maximum lean. Side grip is therefore crucial and it’s likely that the fastest riders will run Michelin’s 16.5in rear tyre after several top men, including Max Biaggi and Carlos Checa, raced 17s at Mugello.

Catalunya is also very bumpy, partly thanks to the frequent visits made to the track by F1 car teams, and there are several corners that feature negative camber, some with blind entries. Such features require a well-balanced chassis, though engine performance is also important for the 300kmh-plus straight.

Bike set-up is further complicated by the region’s variable weather pattern. Wind direction often changes at Catalunya, playing havoc with gearbox settings, as well as blowing sand and dust on to the circuit. And there can be big changes in temperature during the course of a day, making tyre selection difficult.

After Catalunya, the action moves north to the Netherlands, for the Dutch GP on June 30, and thence to Britain, for the British GP on July 8, mid-distance in the 2001 World Championship season.