A cyclist who holds the Guinness world record for a trek from Alaska to Argentina describes another adventurous jaunt, the longest link of a round-the-world trip across Eurasia and the US. Accompanied by his brother and two Russians -- a teacher and a biologist with medical training -- the author reached the Soviet border on June 4,1990 and ""spent the next 124 days biking eastward through grasslands, mountains, and mud to get to Vladivostok,"" traversing 13 time zones in the 7,353 miles. After summarizing the trip's early stages, Buettner focuses on the group's Russian experiences -- the richly varied terrain (some of it almost impassable with mud or boulders), the food, the helpful people, their lifestyles. A profusion of the author's excellent color photos enliven each spread; useful maps in each chapter follow the group's progress, with insets to place areas of detail in larger context and keys to elevation (of particular interest to bike riders). A fascinating journey that will appeal both to young athletes and to those who appreciate Buettner's openhearted response to, and appreciative descriptions of, the friendly people he met along the way. Pronunciation guide; glossary; index.