Fans from around the world will descend on Matterley Basin, near Winchester in Great Britain, this weekend for the 60th Motocross of Nations - the end-of-season team event which will hopefully provide a fitting finale for two record-breaking careers.

Motocross legends Stefan Everts and Ricky Carmichael will both retire from full time competition at the end of this season - Belgian Everts with ten world championships to his credit and American Carmichael, who will continue to race only in select events, with 15 AMA titles.

With Everts spending his record-breaking career in Europe and the equally successful Carmichael in America, the pair have rarely clashed together on track - Carmichael having dominated in their previous Motocross of Nations appearances - but fans are hoping for one final showdown between the two greatest riders of their generation this weekend.

But while Everts will arrive in England at the top of his game - fresh from winning his 101st and final grand prix - Team USA captain Carmichael may not be able to compete after suffering a shoulder injury in the AMA season finale at Glen Helen on September 10.

Suzuki rider Carmichael, who confidently guided USA to victory last year in Ernee, France, is facing a race against time to recover from the injury - with a final decision only likely to be made at the last possible moment. Whether he rides or not, RC will surely be present to cheer his team-mates on, with his RM-Z450 being given to AMA team-mate Ivan Tedesco, part of the victorious 2005 team, should Ricky be unable to compete.

Losing Carmichael would be a massive blow to Team USA and the Motocross of Nations fans alike, but America can still count on the services of Carmichael's AMA title rival and reigning World Supercross champion James Stewart, plus newly crowned AMA Lites Motocross champion Ryan Villopoto.

Second to the USA last year, Team France will arrive at Sunday's starting gate with two 2006 Motocross world champions in their line-up. 18-year-old Christophe Pourcel, who wrapped up his first MX2 title last Sunday in Ernée, and Yves Demaria, winner of his second MX3 title, will be two key elements in Team France's chase for success. They will be joined by Christophe's elder brother Sebastien, who will have the opportunity to ride the 450cc Kawasaki he will race full time in 2007.

Completing the 2005 podium were Belgium, which will field Suzuki team-mates Kevin Strijbos and Steve Ramon - second and third behind Everts in the MX1 World Championship - beside Stefan this year. Everts and Ramon will race their usual 450cc machines, while Strijbos will race on the smaller 250cc machine. Belgium is considered the second pre-event favourite, behind America.

But one nation itching to cause an upset is New Zealand. The Kiwis turned heads with fourth overall last season and will again call upon the services of 2005 MX1 runner-up Josh Coppins and former MX2 World Champion Ben Townley. Coppins is the only rider other than Everts to win a grand prix this season, while Townley has shown impressive pace in his brief AMA appearances this year. They will be joined by Cody Cooper, a leading rider in the New Zealand National Championships.