BB width and front shifting
I have a Giant TCX cyclocross bike with shimano 105 components, all except a bontrager ISIS drive cross crankset. The bottom bracket I have is a 113mm, and I am having a problem where I have my front derailleur set all the way to allow it to extend to the furthest limit, but I still need to shove the shifter very hard in order to make the shift to the outer ring (where it makes a sluggish shift and sometimes rubs on the cage). I noticed that there is also a commonly available 108mm bottom bracket... would putting in a shorter BB help with my shifting issues? Or would the 5mm less not make a difference?