Bob was raised through his early teen years with his older stepbrother, Ed, who enlisted in the US Navy, and then soon died in 1942, at the onset of World War II.

That year the family moved briefly to San Francisco, then across the bay to the rural town of Hayward, California.

One of his frequent local competitors on the streets was Ed Elisian, a teenage boy from nearby Oakland, California.

In late 1944, Sweikert enrolled in the US Army Air Force, but suffered a severe knee injury while training at Lowry Field in Colorado.

On Memorial Day, May 26, 1947 Sweikert ran his first race for prize money at the Oakland Speedway, and finished second.

He ran seventy-two races that first BCRA season, finishing 14th out of 130 active members in the annual point standings.

In January 1953, Sweikert married his high school sweetheart, divorcee Dorie with her two children, with whom he had recently become reacquainted.

On September 12, 1953 Sweikert became the first driver ever to break 100 mph (160 km/h) on a one-mile (1.6 km) oval track, at the Eastern Speed Dome, Syracuse, New York.

[citation needed] On September 11, 1954 Sweikert became the first driver ever to average 90 mph (140 km/h) in a 100-mile (160 km) race, with his win in the Lutes Truck Parts Special #17 car at the Eastern Speed Dome in Syracuse.

In May 1956, at his final return to the Indianapolis 500, Sweikert began in the 10th starting position and came in for a 6th-place finish, with the team's D-A Lubricant roadster.

The sprint car flew over the edge of the track, down the embankment, and landed a hundred feet below, where it briefly burst into flames.