Eric Young: 54 SB in 2000, 31 SB in 2001
Utilityman Eric Young set a career high in stolen bases with the Cubs in 2000 where he collected 54 in his age 33 season. During his only two seasons with the team, he exceeded the 30 stolen base mark. Young was released in free agency after 2001, so he missed the playoff run in 2003. After his playing career, Young became a coach and he has been the first base coach for the Atlanta Braves since 2018.
Ryne Sandberg: 32 SB in 1982, 37 SB in 1983, 32 SB in 1984, 54 SB in 1985, 34 SB in 1986
Ryne Sandberg accomplished the 30 stolen base feat five different times for the Cubs and his 344 career mark ranks third in the organization all-time. If you only count players after the dead ball era, Sandberg is undoubtedly the best base-runner in Cubs history and his speed was just one of the many tools that landed him in the hall of fame. His 32 stolen bases in 1982 contributed to his NL MVP win.
Other than his speed, Sandberg was an excellent defender up the middle (9 Gold Gloves), a dangerous hitter (7 Silver Sluggers) and a 10 time All-Star.