CYCLING - BMX: Australian cyclist Sam Willoughby completed a stellar BMX season with victory in the American series to complement his Olympic silver medal.

Fellow Olympian Caroline Buchanan was runner-up in the American women's series event which ended in Oklahoma on Saturday.

Despite being on equal points heading into the third and final race, Buchanan was unable to come back from a push into the first corner, giving American Dominique Daniels a record five straight series titles.

Willoughby's second ABA overall title came after second placings in all races.

Buchanan and Willoughby both finish the season No.1 on the UCI world rankings and Australia ranked as the highest nation in BMX.

Canberra rider Buchanan claimed a record six international time trials during the year, including the Olympic time trial, and gets the rainbow jersey for that category.

"I have set many goals high this year and accomplished most," said Buchanan.

"After the Olympics I really needed a break but I wanted to finish off the world cup season and claimed the overall so that was satisfying.

"Being in contention for the number one American title was great too and I walk away from this season with my head held high."

Willoughby will spend Christmas in the US while Buchanan will return to Canberra early in December.

The former two time world champion mountain bike rider will race three Australian downhill events.

AAP