Tips for front derailler adjustment?
Campy Super Record clamp-on front derailler on Campy SR 52/42 chainrings. recently I tore the bike down completely, including removing the derailler. I remounted it following the advice on Park's website, leaving about 1mm clearance between the bottom of the outside flange and the chainwheel, and the flange is parallel to the chainwheel (can't remember exactly how it was originally!). I seem to be having trouble going from 42 to 52, none at all the other way. It helps if I only pedal lightly while shifting, but still it might take 2 or even 3 seconds of chattering before it climbs aboard.
Any suggestions? I know that I said I like primitive in another thread, but it seems to me that it was better before the overhaul.
Is the chain worn? Or maybe the chain rings?
Other than that you may want to try adjusting the angle that the dérailleur sits, I've had good luck having the front of the dérailleur slightly 'toed in'.
I'm grasping at straws here, hopefully someone more knowledgeable will chime in.
Could the cable not be as tight as it could be and thus you are losing some of the needed travel in and out? The other thought, of course, has to do with adjusting the high limit screw. Even just a little tweak around the seat tube could cause the difference.
and the other variable is the clocking of the derailleur cage plates to the chainring. I usually set the inner cage plate parallel to the chainring, to give it a better push. my only exception is when the chainline is screwed up and I need to swing the cage in or out a little to accommodate the out of line shifts.
It'd be interesting to see how others do this - I arrived at this method just by trial and error. There very well may be a better way to set the derailleur.
Chain is not worn, and the chainwheel teeth are in good shape. I think that I'll put a bit of toe-in in the outer plate and try that. The inner plate is "toed-out" with respect to the outer one; maybe too much so in my case.
If I can't get a front derailleur to shift well - after checking the usual variables like height, angle, cable tension etc. - I try toeing it in, but typically with the rear of the plates slightly more towards the frame. Sometimes this works wonders...