Originally Posted by
Velocivixen
If the guide pulley is far away from the largest cog try loosening the "B" adjustment screw in the back. It changes the angle of the derailleur. That doesn't sound like it's causing you to not be able to shift to smallest cog, but you never know. Could be a contributing factor.
If it's the Campy SuperRecord RD I'm thinking of, then there is no B adj screw. That all came later. I've decided that any time an RD is not working well is the time to ensure the alignments are correct. The dropouts need to be parallel and the RD hanger needs to be right. And it's worth being fussy about those alignments - measured carefully vs just eyeball'n it. Then be sure the chain length is correct - add or delete one link pair and move the axle in the slot to optimize the length at the 'four corners' of the transmission (big-big, big-small, small-small, small-big). Rather than keep pushing pins in and out, I remove my Missing Link and use a hooked wire to close the chain and move the hooks to 'add and delete' links. When I have the length I then push pins.
I've even gone so far as to grab two lengths of thin wood (sorta like chop sticks, I keep that sort of thing around) and clip one length to the large cog and the other to the pulley cage. The wood strips are straight and about 8 inches long. They serve as 'winding sticks' that really highlight any mis-alignment between the RD and the FW.
Yes, I'm really boring to talk to at cocktail parties and family reunions.