Eddy Merckx has encouraged Fabian Cancellara to attempt to break the hour tecord but has warned that traveling to altitude produces as many problems as it does advantages.
Merckx set a new hour record at the height of his career in 1972, covering a distance of 49.431km in Mexico City with only Chris Boardman (49.441km in 2000) and Ondřej Sosenka (49.700km in 2005) doing better in using a traditional track bike as per the UCI rules for the hour record. All other record attempts are now officially categorised as 'best human effort' including success performances on aero bikes by Francesco Moser and Graeme Obree.
Cancellara has confirmed he is considering an attempt at the hour record but his Trek Factory Racing team has denied setting a date in early August for the attempt. The UCI is currently considering the rules for the hour tecord and the use of some kind of aero bike could considerably help Cancellara's chances. The Swiss rider is currently focused on the cobbled Classics and is one of the favourites to win Sunday's Tour of Flanders.
The new Aguascalientes velodrome in Mexico sits at an altitude of 1880m and seems the ideal location for an hour record attempt but Merckx warned that even a rider of Cancellara's power and experience will need to prepare for the rarified air.
"If Boardman and Sosenka were able to do then I think Cancellara can do it for sure," Merckx recently told Cyclingnews.
"He's strong but we'll have to see where he wants to do it. I think he wants to try in Mexico. It's better to do at altitude but you've got to prepare for it."
"The altitude is an advantage because it allows you to push a bigger gear. But you have to be able to handle the altitude. Before I did the hour record, I trained in my garage for six weeks, with an artificial altitude of 2000m."
Merckx is known as the Cannibal and is the most successful rider in the history of professional cycling, yet he has described the hour record as one of the hardest thing he has ever done on a bike.
"It's very, very hard," he said. "I couldn't walk for a few days after I did it. That's how hard it is."