The first TT on the public roads around the town of Assen was held in 1925, and "Speed Week" has continued ever since, interrupted only by World War Two. 

Held close to mid-summer's day, the race draws huge crowds, a northern rival to Jerez as the most popular GP. Tradition dictates that the Dutch TT is held on a Saturday - all other GPs take place on Sunday. 

At 3.759 miles, Assen is the longest track on the calendar, and with a lap record at more than 110 mph it is also the fastest.   Assen has the longest-standing lap record in GP racing - set by Kevin Schwantz on a Suzuki in 1991, as he held off Mick Doohan in a race-long battle (they finished less than a second apart).

Over the next eight years, not even five times champion Doohan has been able to beat that blistering lap, though last year's race winner Tady Okada came within a couple of hundredths of a second, with next-fastest Kenny Roberts only a couple of tenths slower.

In fact, the time has been beaten ..... a handful of riders have gone faster in practice, but it is race laps that count as the lap record.  One reason, according to rider Kenny Roberts, is that the surface has never been in better condition than back in 1991, when the 3.8-mile circuit had just been fully resurfaced and some sections widened. "Each year it gets bumpier and the tarmac gets that bit more worn."

Assen still retains traces of its public-roads origins - it only became a closed circuit in the Nineties, when a new bypass road was completed. It is especially unique in its complexity - each section of the circuit is made up of strings of mainly high-speed corners. A mistake in any one bend costs times throughout the remainder of that section, and Assen puts a premium on good machine handling, as well as smooth and accurate riding. 

This is the last year the track will be used in its present form for a GP - in September work will begin on a new layout, with the stretch behind the paddock moved backwards to make more space inside, and another corner eased for safety reasons. 

For Kenny Roberts Jr, the Dutch circuit is a chance to get his World Championship defence back on course, after an excellent day of testing changed his mood following two bad races.

For team-mate Sete Gibernau, the aim is to capitalise on his rapidly improving form at a favourite circuit, after the race of his life last weekend at home in Catalunya.

There is a third reason to look forward to the race - for one of the oldest and best-established teams in GP racing to share in an important piece of history at the oldest and best-established circuit on the calendar.

This year's Dutch TT is not only the last all-two-stroke 500cc event at the classic circuit. It is also the last time the current circuit will be used, with major alterations already under way for next year.

Assen has the oldest lap record on the calendar - set in 1991 after the circuit had been resurfaced. It belongs to Suzuki and their famous former champion Kevin Schwantz. Riders have gone faster since then in practice, but rain and other circumstances have prevented the record being broken in a race. If it survives again this year, it will survive forever. And if there is to be a new record in perpetuity, Suzuki want to be the ones to hold it.

The TT's greatest importance is as round seven of 16 in this year's championship battle. So far, title-holder Roberts has run into difficulties while Italian rider Valentino Rossi has led a charmed life to move ahead on points. Approaching the halfway point, it is vital for Roberts to find a way to turn the tables before too much longer.

Very positive tests the day after the Catalunyan GP have given the American new heart for the struggle. "It looks like we're not in it - but if the chips fall our way, we could be," he said, reflecting a mood of optimism following a day where he was the fastest man on a track where all the big stars were also in action in post-race tests.

Last year Roberts qualified on the front row of the grid, and was leading the race when a rare mechanical problem triggered a spectacular crash.   His team-mate, Sete Gibernau, finished third here in 1999 - just one hundredth of a second behind Roberts, after tussling over the closing laps. Last year he had a good race, battling for the lead after the wet-weather restart, though dropped to seventh on aggregate times.

Kenny Roberts - "It's going to be fun to see how well the bike works with the new stuff we stumbled on at the Catalunya tests. It's mainly in the suspension. We don't usually have time to dedicate a whole test day to suspension, but at Catalunya there wasn't much else we had to do - and it worked out real well. The rideablity of the bike is much better. You don't have to fight it so much. Which is really important at Assen. Do I like the track? We'll see. Depends if we win or not."

Sete Gibernau - "I've said all year that I was sure if we kept working the results would come. My team put their usual big effort in at Catalunya, and I rode every corner at 120 per cent. Assen is a different kind of track, with less emphasis on the bike, and I believe that we can get a good result without having to live so desperately. I like the track very much - I finished on the rostrum here in 1999. Racing is so close this year that the smallest difference can make a big difference to your finishing position - but my target at Assen is to do even better than in Catalunya."

Warren Willing, Suzuki GP Technical Chief - "Assen is very different from Catalunya, where you have the bike leaned on its side for long corners - but I think that the suspension improvements we found at our tests there should help us to a degree, with the damping better matched to the behaviour of the 2001 chassis. At Assen, you lean the bike over and pick it up more quickly. The crown in the road effectively means the corner apexes are banked, so you're also putting more load into the suspension at that point. You stiffen the suspension for that, and also set the damping to suit the more rapid way the loads are applied and released. Assen is fairly unique, and technically very challenging."

Of course for Jurgen van den Goorbergh this will be his home GP.   The team believe the light and agile three-cylinder Proton KR3 is tailor-made for the sinuous curves of the 6.049km track, the longest of the year. The complex layout, with fast corners leading one into the next, takes the emphasis away from sheer horsepower and hands the advantage to a machine capable of faithful and accurate steering and high corner speeds. 

Assen is also the first of what team owner Kenny Roberts Snr. has tagged "The Big Four" - Assen, Donington Park, Sachsenring and Brno. These are all "handling" circuits, and the tracks the team has been looking forward to all season long. 

At the Catalunyan GP at Barcelona two weeks ago, Jurgen qualified on the second row of the grid - in the thick of the class leaders - for the second race in succession. He finished ninth, his best result of the year so far, and his second top ten. Two weeks before, he'd finished tenth in the rain-hit Italian GP.

Van den Goorbergh has yet another trump card to reinforce an already strong hand. Three weeks before the race he tested at Assen. Firstly, this was an opportunity to consolidate various improvements to the machine during the season, and fix a couple of niggling problems. Secondly, it gave a base-line for gearing, suspension settings and tyre choice. Thirdly, it was a valuable chance to familiarise himself with the KR3's special character at this most difficult of circuits. 

Jurgen - "We tested at Assen before Barcelona, and for two days I had a happy smile on my face. I have never been so quick during testing at Assen, but the lap time wasn't the point. We were working on chassis developments, and we found a really good balance. At Assen it's very important to keep on line, and for the bike to be quite stable. We also found some more power. The Proton is the best Assen bike I have ever ridden. Nowadays, a lot of people are capable of getting on the rostrum. I think it's also possible for me at Assen."

Repsol Honda's Alex Criville finished 2nd here last year after a race long battle with Alex Barros.  “It was a very hard-fought and tough race”, remembers Alex Crivillé. “Until the very last moment I tried to get away from Barros to make sure of victory, but it wasn’t possible and Alex had a big enough advantage from the first leg so I had to settle for second. I have many other good memories of Assen, too, apart from 1997 when I seriously injured myself in a terrible crash. I celebrated my first 500 victory in Assen, and it is one of the circuits where I have my best races altogether. It’s very technical and demanding for the rider, and that’s where the key to success is. In Assen, it is the rider who makes the difference.”

His team-mate Tohru Ukawa also believes that “Assen is a difficult circuit, probably the most complicated one of them all this year. I won here last year, and I would certainly like to repeat a podium finish, even though I’m well aware that I will have to ride very fine and precisely with the 500 if I want to be fast”.

Max Biaggi comes to the Netherlands this weekend in a confident mood after scoring more points than any other rider in the last 3 races. "We have already shown that we can win when everything is going right, since we tested at Mugello in May my bikes have been good and the team is working really well.  I love Assen and I think we can have another good weekend there. It’s a very unusual circuit, different from the other tracks we go to, and that always makes it a bit special. As usual, I’ll work with Fiorenzo Fanali, Biaggi’s crew chief and the rest of my team to make sure we have a good set-up for the race. The season is going pretty well for us at the moment, we’ve had some good results but we still need to work hard to reduce the points gap."

His team-mate at Marlboro Yamaha, Carlos Checa, is hoping to perform at his best in front of his home crowd after a disappointing result in Catalunya. "Catalunya was bad for us, things can only get better at Assen. It’s a fantastic track, somewhere very special," says Checa, who finished second in the 1997 Dutch Grand Prix, behind track master Mick Doohan Honda. "Unlike other circuits, the corners are quite heavily banked and there’s a lot of grip, so you can really throw the bike around. I know I can be fast there if we have the correct set-up."

Honda's World Championship leader Valentino Rossi comes to Assen this week hoping to extend his championship advantage with victory at GP racing's most historic venue.

Rossi, winner of four of the six 500 GPs run so far this year, wants to continue making his own history this Saturday. With this year's 4 wins Rossi's career 500 total comes to 6. That does not sound like much but 500 wins are hard to come by and Rossi already sits equal-19th on the winners list. 5 more wins and Rossi will be equal 15th on the winners list with Britain's Phil Read. If Rossi gains those 5 victories this year and takes the title he will not only equal read on the all time winners list but also join Read as the only 2 riders in history to have won the 125, 250 and 500 triple crown.

A Dutch 125 GP winner in '97 and 250 GP winner in '98, Rossi loves Assen. "It's a very, very difficult track but I like it a lot," says Rossi who finished sixth in his Assen 500 debut last year, a two-part race stopped and restarted due to rain. "Assen is very technical, especially on a 500. The straights aren't straight, so you're always changing from one direction to the other, so you have to be very much in control. Also, some of the corners are banked and the road is crowned, so we run stiffer-than-normal suspension settings to keep the bike more stable."

Assen lap record holder Kevin Schwantz is the latest in a long line of former GP greats to heap praise upon Rossi. The two have much in common: a lanky physique, massive natural talent, a deadly serious but joyful approach to motorcycle racing and global popularity.

"The big thing about Valentino is that he's having fun doing it," explains Schwantz. "He's out on the track every time wringing the bike's neck, trying to get everything he can out of it. Plus, he never moans about 'missing the set-up' and he seems like a guy who can say 'okay, we get beat on occasion, we're not superhuman'. That's all part of his secret."

After his fourth win of the year at Catalunya two weeks ago, Rossi stayed on at the Spanish track to test a new chassis which should further improve the handling of his NSR500s. He currently enjoys a 26-point lead over arch-rival Max Biaggi (Yamaha).

Alex Barros and team-mate Loris Capirossi go to Assen full of confidence. Both men perform super well around the sinuous circuit, Barros winning last year and Capirossi qualifying on pole.

"Last year I scored my first win of the year at Assen and I hope I can repeat that this time, both Loris and I should be strong again this year, I think our bikes will be good for this track," said Barros.

Capirossi rode at Assen last year after breaking bones in his left hand during morning warm-up. "I had to race because I love Assen so much," says the Italian, currently third in the all-Italian 500 points chase. "It is my second favourite track, after Donington, and I'm very fast there. The track is good for my riding style and I think our bikes should be good there, we're closer to Rossi's bikes than we were at the start of the year."

Briton Leon Haslam (Shell Advance Racing Honda NSRV500) returns to racing this week after a month's lay-off with a broken wrist. And Assen is as significant a track for the Haslam family, as it is for so many other GP racers, for it was at Assen '85 that father Ron Haslam scored his best-ever GP result with second place behind Randy Mamola (Honda).

Another victim of a wrist fracture, Garry McCoy, will be returning to the track this weekend after missing Catalunya through injury.  His Red Bull Yamaha team-mate Noriyuki Haga will continue his tortuous 500 learning curve.