higher speed crankset means the chainrings are stamped narrower to squeeze into the narrower chains. Your wider 8spd stuff will fit onto it just fine. Maybe take a slight durability hit since the rings are lighter.
the speed of the front derailer itself matters more; a wide 8spd chain will rub in more gears if you try to run it through a narrow caged 10spd front derailer.
Last edited by xenologer; 11-08-12 at 12:49 AM.