Spies, who as an athlete won a two-man bronze medal at the 2003 World Championships, has been the head coach since 2016.

German athletes have won six of the seven Olympic gold medals on offer since then, as well as dominating World Cup and World Championship races.

"With René we always know where we stand," German Bobsleigh and Luge Federation chairman Thomas Schwab said.

"He is a very innovative and, above all, balancing and bringing-together trainer. 

"We're happy about his uncomplicated signing."

Spies' renewal follows head skeleton coach Christian Baude also signing a new four-year deal which covers Milan Cortina 2026.

Germany won both skeleton gold medals at Beijing 2022 - the country's first - to complement the bobsleigh success.

Francesco Friedrich's sleds won two-man and four-man gold medals at Beijing 2022 - as they did at Pyeongchang 2018 - while Laura Nolte and Deborah Levi secured the two-woman title.

Friedrich plans to retire after Milan Cortina 2026 and Spies already has succession planning in mind.

"We need an increase in the quality of training for youngsters and an increase in the quality of training for coaches," Spies said.

"We will achieve this through targeted sport-specific training."

Spies has outlined plans to have Germany's leading coaches working with European Cup athletes and at lower levels to ensure emerging sleds get full support, as well as stressing the importance of maintaining world-leading levels of bob design.