Kristers Serģis is a retired Latvian sidecarcross rider and five times World Champion. Kristers Serģis came to the sidecarcross sport through his father, himself a rider in the days of the Soviet Union. He made it possible for his son to take up the sport after Latvian independence in 1990. Through sponsorship from a timber building company in Cēsis, it was possible for him to turn professional, a rarity in this sport. To be able to keep the traveling distances short, Kristers now lives in the Netherlands but returns to Latvia in the off-season to work at his motorcycle dealership, "Kristers Serģis Moto". Kristers Serģis has been voted "Latvian sports person of the year" multiple times, winning the award in 1997, 1998 and 2000. At the end of the 2008 season, Kristers Serģis retired from the sidecarcross sport.
Kristers Serģis entered the sidecarcross world championship in 1992, with Artis Rasmanis as his passenger. After two seasons with limited success and starts, he switched to Normunds Bērziņš as his partner for 1994 and 1995 but continued to have only a small impact on the race circuit. In 1996, he returned with Artis Rasmanis and in the fourth race of the season they achieved their first race win, on 21 April in Betekom, Belgium. The season after, their fortunes improved greatly and the duo won their first of five world championships this year. In 1998, they repeated their success and in 1999 they missed out by only one point to Daniël Willemsen / Marcel Willemsen on their third triumph. Also, in 1998, they won the German sidecarcross championship. However, Serģis / Rasmanis continued their successful partnership with three more titles in 2000, 2001 and 2002. With their fifth title they became record holders in world cup wins in this sport. Previously, two drivers had archived four crowns, but none of them had five. In the 2002 season, they archived an amazing 13 wins in a row and 24 all up. After this, Rasmanis left the team and Sven Verbrugge from Belgium became Serģis new partner. After a second place in 2003, the team fell to seventh in 2004 due to an injury for Serģis, which put him out of action for three month, and split up after this season, Verbrugge joining Daniël Willemsen instead. In turn, Kaspars Stupelis came from Willemsen across to Serģis and the two finished runner-up in the 2005 season. In 2006 they raced in only two events and Sergis failed to score a GP victory for the first time since 1995, finishing19th overall. The Serģis / Stupelis partnership returned in 2007 and with good results and one GP win they archived third place in the overall standing that season. However, Daniël Willemsen overtook them as record holders, having won six titles now. Despite this, the two Latvians Serģis / Rasmanis remain the most successful outfit in the history of sidecarcross world championship since Willemsen frequently exchanged partners in his six titles.