adjustment help
 

Attachment 541969

My old chain was just fine but the lbs guy said I needed a new one. They put one on but now the chain kind of drags on the chain cage when the chain is on a lower cog. the photo has arrows pointing to a couple of screws that have high and low stamped on them. Are these adjusters for this? If not do I mess with what I have enclosed in the box? T

No the "limit" screws you're pointing to have only one function, which is to set the inner and outer limits to the range of travel. The actual position of the derailleur within that range is determined by the cable.

If you have an inline adjuster, this is easily tweaked back home. However, changing a chain should not have had any effect of the FD trim, so you need to ask them if they fooled with it, and if so, they should correct their work. If nobody adjusted the FD, then you need to see what else may have changed.

If the shop changed the chain and you are now experiencing problems that you were not having before the work was done, the best thing to do is to go back and ask them why this is. If they want you to change more parts at an additional charge, be firm and refuse, politely. Limit screws that you have circled in your photo should be set and forget, I cannot remember having touched limit screws on a front derailleur on any of my bikes unless I changed a crankset (or the derailleur itself)

If you want to try to fix this yourself and save a trip to the LBS. Then watch some Youtube video on how front deraileurs are set up to get a better understanding of how they function. Visual tutorials are much better than text. FD's are not as complicated as they look.

It could be 1 or 2 or 3 things

either

1. The front derailleur is misaligned and the cage is not parallel to the chainring. If so, you'll need to loosen the FD clamp and rotate it. Then re-tighten. Also pay attention to the gap between the tips of the big chainring teeth and the bottom edge of the outer cage. The gap should be around 1-4mm.
Loosening the FD clamp will effect the cable tension, so the cable may also need re-tensioning at the cable fixing bolt afterwards.

2. The inner limit screw (the screw closest to the frame) needs turning outwards (allowing the inner cage to move closer to the frame). If the derailleur cage doesnt move inwards when doing so then its likely a high cable tension issue. If it does move, aim for the gap between the inner cage and chain to be 1mm or less.

3. The cable tension is too high. If you have a inline barrel adjuster on the cable to the front derailleur. Try turning it inwards. Look down at the cage while doing so. Does the inner cage move inwards at the same time ? If yes, adjust so the gap between the inner cage and chain is 1mm or less.

If there is no barrel adjuster. Try adjusting the inner limit screw first.

If that makes no difference then you'll need to loosen the cable fixing bolt (to release the tension on the cable). Adjust the inner limit screw (gap 1mm or less). Then pull the cable with pliers and clamp.


OP , How many miles did you ride on the old chain ? just out of interest