To investigate the effects of alcohol on the ability to ride a bicycle, practical cycling tests were carried out at different blood alcohol concentrations (BAC). For this purpose, various alcoholic beverages could be consumed from around 2 p.m. until 11 p.m. Afterwards, the test persons spent the night on the trial site and were provided with dormitory sleeping accommodation. On the following morning, beginning at around 8 a.m., a final cycling test was performed. The performances of those test persons who had returned to state of soberness and of those with residual blood alcohol levels were compared to the performances on the day before. The practical ability to ride a bicycle was significantly reduced in the postalcoholic state compared to the rides of the day before. The relative cycling performance in the postalcoholic state was comparable to the rides under the influence of BAC of around 0.30 g/kg. There were no remarkable differences between the groups with and without residual blood alcohol levels regarding the rides on the next morning. Therefore, it can be assumed that the direct influence of residual blood alcohol levels plays a minor role for the ability to ride a bicycle in the postalcoholic state. Instead, the side effects of the high amounts of alcohol that were consumed the night before are crucial.