Originally Posted by
ryoanji
I have 2005 Specialized Allez running 9 spd 6500 ultegra double. I am planning to convert it to triple and have purchased 9 spd long cage RD and ultegra 6603 crankset. I belive the shifters that I have are triple compatible. But now I have hard time sourcing ultegra FD triple for my bike. How much will I lose by going with 105 FD? I know ultegra is 52-39-30 and 105 is 50-39-30.
hi
first the basic answer:
105 FD -
if that's a 9-speed 105 FD-5504 front derailer, it is compatible with a 9-speed
ST-6510 or ST-5510 shifter (which you'll need, though you didn't say it.)
The 9-speed long cage RD is probably a 6500-GS or something which will be compatible with this shifter.
On the other hand, the ultegra 6603 is designed for 10-speed so I would stay away from that one with your components. There would be some different spacing between the chainwheels, different bottom bracket requirements, or something else that is likely to get you. Shimano doesn't list compatibility between 9-speed derailers and 10-speed cranks like this so I'm sure it's not an ideal set up, though it may seem to work.