I have adjusted the RD as much as I possibly can, but I still cannot get it to shift into the 11 cog. I used a new Wipperman chain and shortened it to the exact length as the one I had been using with the 12-27. Could this be the issue and I just need to shorten it or are there other adjustments that need to be made with the RD? Bent RD?
have you adjusted the limit screws?
I haven’t touched the limit screws, only the barrel adjuster. I will give it a try. Thanks!!!
The B screw (the one on the back) will need to be adjusted for the different height of the 27/23. The min/max should be basically set.
Edit: this is how I would approach it, I have no idea if it is completely right or completely wrong.
you mention the chain is the same length as the 12x27…?
1st-
make sure cassette is on hub- tight- properly installed- with spacer if necessary- if using a shimano 10 speed cassette with a hub that’s not the 7800 model.
2nd-
set the limit screws- best done without the chain on for most precise visual- set the 11 cog- by having the RD top pulley partially below and partially to the right (outside) of the above 11 tooth cog. The center of the 23 cog should be adjusted to be directly above the RD pulley
3rd-
make sure you have the proper chain length- you might need to make it shorter for the 11x23… put the chain on the 11 and on your inside (smaller) gear on your crank. The rear derailleur should be perpendicular to the floor.
4th-
set b limit screw- (small screw that touches rear dropout) so that RD top pulley is below and not touching the 11 and 23, while it is in the small gear on your crank.
5th-
if the above does not work… possilble you have a bend rear drop out making it hard/impossible to shift into the smallest cog… but- if it worked with your 12- (smallest cog) it should work on the 11…
Set the limit screws to establish range of motion for the derailleur, THEN line up the indexes with the cogs with the barrel adjuster.
Adjusting the rd is easy once you know the function of the screws. The the limit screws are responsible for the range of movement of the derailleur. I always adjust these without the cable locked in.
The barrel adjuster just lines up the indexing with the cogs. If your not able to shift into the small cog, then it is definitely a limit screw issue, as you wouldn’t normally use a barrel adjuster for the upper and lower limits of the cassette anyway. When there is no cable tension, the rd chould naturally settle into the 11 tooth position.
Is the chain fouling on the frame as it tries to drop to an 11 tooth cog? Not common, but there are a few bikes with this issue.
you can adjust the limit screws without the chain or cable installled, this is the best way to do it because you can line it up perfectly. For the low end, just push the derailer forward while you tighten or loosen the screws. You can get the jockey lined up directly below the small cog. For the high end, same deal, it’s just a little more tricky because you have to hold against the derailer spring.