shortening chain causes problems
I had a 3 ring setup 24/32/42 I replaced the 42 with a bash. I just replaced the rear derailleur with a GS (medium) shadow plus (had an SGS - long cage). Bike rode fine around on the street, didnt take it on the trail yet. I was reading and realized I probably needed to shorten the chain. So I shortened it, but not quite enough - I had 4 links of overlap. I simply could not get everything adjusted. Specifically the front derailleur would not shift from the big to the small ring if the rear derailleur was on the highest 4-5 gears (smallest cogs). If I rode the bike it actually shifted, but on the stand it would not.
I bit the bullet and shortened the chain by two links so there are only two links of overlap and the bike instantly shifted properly.
chain way too long - shifted fine
Chain 4 links overlapped - could not get it setup properly
chain 2 links overlapped - worked fine
Can anyone explain what was happening here?
Also now that the chain is shorter, when I am on the largest cog and the large ring, the bottom pulley is forward of the top pulley. I seem to recall reading that the farthest it should go is straight below the top pulley. Is my setup bad? I can take a picture if necessary.