I'm swapping out a FC-6703, (Ultegra triple crankset), for a FC-6750, (Ultegra compact crankset). In addition to a new left ST-6700 shift lever, do I also need to swap out the front derailleur from the FD-6703 to a FD-6700? Or, will the triple FD work and shift fine?

(I'm going to keep the RD-6700-GS, (long cage rear derailleur), because I'm running an Ultegra CS-6700 12-30 cassette.)

Hi,

I would be very surprised if you needed to change the derailleur. I think you may be able to keep the shifter as well.

As long as you adjust the high/low screws to make sure you don't drop the chain, I think you should be good to go. If it were me, I'd try the triple shift lever and see if adjusting the limit screws were enough to keep using a triple shifter with a double (I'd expect that it would work - my bike came with a triple shifter and a double crank).

Cheers,
Charles

Good advice. However, be sure to set the shifter cable tension and front derailleur so you use the outer two chainring positions and lock out the granny position with the low limit screw. That way if you inadvertently shift into the missing third chainring, all you get is slack cable. If you use the two inner positions and try to shift into the missing outer position you over tighten the cable and could damage something in the shifter.

Thanks, Charles. Worth a try. I have a new left double shifter already. Purchased a triple set last year, and they sent a double instead. The vendor sent me the left triple and said to keep the left double. In a way, it would be nice to sell the triple crank with a triple shifter, (if I decide to sell them), but I'd rather not change the shifter if not needed because the bike has internal cabling and routing internal cables are quite difficult, (for me).