The highest tightrope crossing by bicycle is 238 ft (72.5 m) by Nik Wallenda (USA) between the Royal Towers of the Atlantis Paradise Island hotel in Nassau, The Bahamas, on 28 August 2010.
Wallenda added this record to his previous individual accomplishment of the "longest tightrope crossing by bicycle." The rope he crossed was supported by anchor cables which were held in place my assistants on the crowd. As for Wallenda himself, he crossed untethered and unsupported, which just a balancing beam as his only method of assistance.
Comments below may relate to previous holders of this record.