Front Derailleur Question (Mechanical Issue)
I'm new to mountain bike maintenance. On my KHS Tucson, I noticed shifting problems and the chain rubs the front derailleur cage. I adjusted the high and low screws so the bike now shifts fine, but the chain still rubs the cage in certain gears.
I know it's hard to fix without seeing it, but is there something I am doing wrong in an adjustment, or is there another reason the cage rubs the chain. Or is this normal to have some rubbing?
I'll take it to the LBS when I can, but for now would love to know how to fix it myself.
Thanks for any info.
Traditional friction or micro-index front derailleurs allowed (required) trimming to the optimum position within the bounds of the inner and outer limits.
Index front derailleurs can't be fine tuned, especially on the middle cog. Their position is set by the click in the lever, and fine tuning is done by adjusting cable length (or tension).
Somewhere on your bike, either on the frame, the levers, or in-line on the housing, there has to be a threaded adjuster which you'll adjust for best trim on the middle chainring, similar to adjusting trim on the RD. The outer and inner positions are automatic based on this adjustment, subject to the limit screw adjustments you've already made.
The key to solving any problem is to understand and address the underlying cause.