ddeand 

I just finished reworking a 2005ish CX bike that came with a Campy Centaur crank. The rest of the drivetrain gear is Shimano 105 from that era. I’m having a devil of a time getting the front derailleur adjusted so it shifts up to the big ring. In order to make the shift up, I have to move the chain to one of the smaller cogs on the rear - then it will barely move up. Any idea why this might be happening? Cable tension? Mismatched parts? Any help is appreciated!

alcjphil

Doubt that it has anything to do with the crank. That would be the last thing I would look at if I were troubleshooting

AeroGut

Two possibilities- either the cable does not have enough tension or the limit screw is not adjusted properly. Easy test is to see if you can push the derailleur by hand far enough to get the shift to work. If you can, the limit screw is probably fine and you need more cable tension. If not, adjust the limit screw to let the derailleur go farther out.

zacster

It could be the chainline is misaligned due to the mix of parts, or the FD is not the right type or mount, or cable tension, or limit screw, or, or, or... Without seeing what is happening it is hard to troubleshoot. Front derailleurs are one of those things I can never get quite right as an amateur mechanic. Try watching the Park Tool video on adjusting these, although most of those videos are geared towards newer bikes with perfect groups and just tweaking that last step.

noglider 

See if the cable is entering the front derailleur at the right angle. Sometimes, at the wrong angle, it can't pull far enough.

ddeand 

Thanks for the suggestions. I got it mostly sorted, although it just barely shifts smoothly. I’ll ride it like this fir a bit and then see if I can reset things. Thanks again!