Searched all over and can't find a clear answer to this.
Just put an Ultegra double 6600 10 speed Crankset on my bike but left the 9 speed cassette in place. Everything seems to work well except that when I am in the small chainring and the second and third smallest cogs on the rear the chain seems to rub on the larger chainring. Will a 10 speed chain fix this problem and if so will it work fine with the 9 speed cassette and F.D.? Thanks for your help.