If this website is correct, Indurain used 190 mm cranks when he broke the hour record:
http://ida1.physik.uni-siegen.de/
It's interesting too how much bike weight varied in the hour record attempts: Coppi's bike in 1942 weighed more than Oscar Egg's in 1912.
Mordecai Silver
New York, NY
>Campagnolo offered 151pcd (and, later, 144pcd) track cranks in 165,
>167.5, 170, 172.5, 175. 177.5 & 180mm lenghths.
>If memory serves, Miguel Indurain used 185mm cranks, apparently based on
>the Nuovo Record forging to break the Hour Record in 1994.
>David Benson,
>Auckland, NZ