Originally Posted by
Fast505
I hear people talking about the chain "floating" over the small ring when downshifting the FD. Having to get a 10 speed crank to complete the 10s drivetrain is too much.
The "floating" (aka skating) problems you were told about came during the transition from 8 to 9-speed. The narrower 9-speed chain would sometimes skate on the teeth of the smaller ring if the shift was made under high chain tension. Even then it was a minor issue.
Shimano and Campy both slightly reduced the gap between the rings on 9-speed cranks by offsetting the teeth of one ring to prevent this problem. Now with the narrower 9-speed gap, the switch to 10-speed doesn't seem to have caused any problems.
I'm running a 10-speed chain and cassette with a 9-speed Shimano Ultegra crank and have had no shifting difficulties whatsoever.