the other question, after I changed it to 27 speed, the Front Derailleur is hard to shift geers, I mean it's hard to shift to small chain ring, someone told me some mistakes
1.maybe the BB's width is too short..but I never change BB, It works good in 24-speed
2.maybe the 9-speed chain is thiner than the 8-speed chain, front deraileur is hard to push chain to the small chain ring
3.maybe the crankset (Truvativ FiveD tandem) only work in 24-speed
what should I do?