The smallest ridden unicycle measures 30 cm (11.81 in) high with a wheel diameter of 16.5 mm (0.64 in.) and has no attachments or extensions fitted. It has been ridden publicly on a number of occasions by Peter Rosendahl (Sweden), the greatest distance being 11.61 m. (38.09 ft) at the studios of El Show de los Récords, Madrid, Spain on 11 October 2001.
Guinness World Records | September 27, 2007