Tom Zirbel

Tom Zirbel (born October 30, 1978) is an American road bicycle racing cyclist from Clear Lake, Iowa, riding for Rally Cycling.

He rode for Priority Health from 2006 to 2009. He came fourth in the UCI Road World Championships time trial in September 2009, and had signed to join UCI ProTour team Garmin–Transitions the following season.

In December 2009, a urine test taken at the 2009 USPRO Time Trial Championships the previous August, in which Zirbel came second, tested positive for DHEA.Zirbel denied having taken the substance knowingly, but he nevertheless voluntarily accepted a two-year suspension, and immediately announced his retirement. His suspension was reduced in March 2011 to 18 months, which had already been served, in recognition of assistance given to the US Anti-Doping Agency. He suggested that, despite earlier comments about retiring, he would seek to resume his racing career.He maintains that he ingested the banned product inadvertently.

In 2011, Zirbel rode for Jamis–Sutter Home. On May 28, 2011 he placed 2nd in the US Pro time trial championship, behind David Zabriskie. He joined Optum–Kelly Benefit Strategies for the 2012 season. In an interview with cyclingnews.com in early 2016, Zirbel confirmed that the upcoming season would be his last as a professional cyclist before retiring. In September of that year, he set a new American national hour record in Aguascalientes, Mexico, completing 53.037km to break the 1997 record of 51.505km set by Norman Alvis.