front derailleur not shifting to small chainring

[MR GERALD O RYAN]

shimano fd c050 top swing front derailleur: Triple. Adjusted cable tension and low stop three times per Park video and other links. There is room to shift low but derailleur won't move on its own.
Will throw chain to low chainring from large ring, but not middle ring

[MR GERALD O RYAN]

It pays to pay attention. Never worked with top swing derailleur before. Turns out the derailleur body was hitting against an newly installed bottle cage and that physically prevented the derailleur from moving to small cahin ring. Sometimes you just need to look at things.

[Jesper]

(08-20-2020, 01:55 PM)MR GERALD O RYAN Wrote:  It pays to pay attention. Never worked with top swing derailleur before. Turns out the derailleur body was hitting against an newly installed bottle cage and that physically prevented the derailleur from moving to small chain ring. Sometimes you just need to look at things.

Welcome,
Interesting problem, I would have thought that the bottle cage would have still prevented the chain from shifting onto the smallest gear even when transferring from the largest one. Essentially the cage was acting like a "limiter screw"; I assume that the cage was only interfering with the derailleur by a small amount.
Was the bottle cage of a "non-standard" construction or bent? I've never experienced, nor seen this problem; but I really only deal with racing/touring frames.
My advice I was going to give was in relation to the height of the derailleur, which may still be part of the issue since if mounted too high it may be what is causing the interference with the bottle cage. I normally set the derailleur outer cage plate about 1/16" (1-2mm) above the large chainring when it is directly above the teeth. I see many bikes with the derailleur cage 1/4"-1/2" (!) above the ring causing poor shifting on a good drivetrain.