113 is the axle length. You need to determine the axle length required for the RX100 cranks. I didn't double-check, but if Sheldon's site says 113, then 113 it is.
As far as shifting the front chainring, it is possible that you have to adjust the front derailer limit screw that controls the outboard movement of the DR.
Apparently it was set for the bb spindle that was on there originally.