hi, I have three chain-rings on the front and the smallest and largest are adjusted properly. I was wondering if there is any way to slightly change the position of the derailer when it's over the center chain-ring. It changes perfectly on and off the center ring but I'd like it to sit a little closer to the smaller ring.

Cable tension?

What the PP means is that you should turn your front derailer's cable adjuster barrel slightly to the left or right, and note any change in the alignment. Adjust as needed, until you get the result you want. This is also done when eliminating scraping against the cage - if desired, run through all the gear combinations and adjust to find the optimal tension where most combinations (or: all except the highest/lowest 1 or 2) don't produce scraping or clanking against the cage when you shift or ride.

Good luck, have fun!

A ham fisted chimpanzee can be trained to adjust rear derailleurs. Fronts, on the other hand, require a bit more precision.

1. If it ain't broke, don't fix it. Since "it changes perfectly on and off the center ring" I'd leave it alone.

2. Every front derailleur adjustment affects the subsequent adjustments. If you decide to fiddle with it my advice is to disconnect the shift cable and start from the very beginning as if you are installing the derailleur for the first time. Park Tool has a good set of step-by-step instructions. Follow them in sequence.

Good luck.

Yeah. F.D adjustments are annoying there's no fine adjust for cage rotation nor height. Both have to be set precisely at the same time - frustrating when shifting only optimally performs in a very narrow range for both. Ugh.

And here is my infamous copy & paste:
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Take the cable off the FD. Now install it from scratch as per Park Tool Repair:

https://www.parktool.com/repair/readhowto.asp?id=75

And BicycleTutor:

https://bicycletutor.com/adjust-front-derailer/

When you have it properly trimmed and are ready for the cable - a new one wouldn't hurt - you want to pull the cable taut - not too tight, taut. Then apply 48 to 60 inch-pounds to the pinch-bolt. Then put it through it's paces.

It's always easier and faster to install a FD from square-one, than it is to make adjustments with it already attached. This tends to fix one thing - while throwing another out of kilter. Start fresh. You'll get it.

Adding an inline barrel-adjuster can solve many problems with the cable coming loose - or being too tight.

Barrel Adjusters:

https://www.biketoolsetc.com/index.cg...rrel-Adjusters

When putting a cable on a FD, I like to wrap it all the way around the pinch bolt so it points back down behind the seat tube... much tidier.

Apply tension with longnose pliers before tightening the pinch bolt.