HELP! Chain rubbing on Front Derailler!

my chain rubs on the outside of the front derailler (Shimano Ultegra) when i'm on the inner front cog and any of the lower 3 (outer) cogs in the back. It's a trek 5200 and i don't think there's a rotational adjustment if that's what needs to be adjusted. I would rather do it my self than take it back to my LBS if anyone out there can help.

Ya tried using the trim function in the shifter.Small click rather than the big one to change rings.

thx for responding, ya i just tried that. it doesn't help.

That's it's job if the derailer is adjusted properly.

inner ring (front) + outer cogs (rear) = likely rubbing situation

Same goes for the reverse. Essentially a shifting no-no; undue stress on the drivetrain. Right, Boudreaux?

i totally agree it is a "shifting no-no" to be on either outer/inner or inner/outer. but i don't think it should be rubbing when i'm on the second to outer on the rear and inner front. (it also slightly rubs on the third from the outer in the back).

I'd say it's not terribly uncommon for some rub to occur one or two cogs in from the extreme (high or low) if you're in the wrong chainring up front.

A properly set-up trim position should permit you to go all the way (though you shouldn't do it) -- when you say you've "tried that and it doesn't help," what does that mean, exactly? Does that mean that you perform a half-click on the shifter and you distinctly see the derailleur move into a corrected position, only not far enough to fix the rub?

Or does it not click into an adjusted trim position at all, simply springing back to the original location?

The small/small is a no no.Assuming you have rub in the next 2 smaller and the derailer is properly adjusted,and you are using the trim properly, then you just live with it.

ya so i gave up playing with the trim and took it in to my LBS and it ended up being a bad cable. He changed the cable and now it works perfectly.

Glad to hear it -- happy riding!

try not to use inner f.der and the small 3 cogs in back, because of rub but also for the unnecessary stress put on the chain from the lateral angle. the trim would help the the rub, but doesn't change the angle the chain is coming off the chainring. save the life of the chain, its pretty important.

~the turtle

Hooey

Have you reached your birthyear in number of posts yet, Boudreaux?

1. release the front derailleur cables
2. shift to the biggest rear cog.
3. adjust any of the 2 front derailleur adjustment screws to eliminate rubbing on the front derailleur plate.
4. reinstall cable.
5. shift to the big ring .
6. adjust screws just enough to eliminate chain from skipping over the big ring.
7. shift to the small ring and smallest cog.

1a) make sure derailer is at proper height and properly aligned. 2a) have shifter in SMALL chainring position. 3a) adjust LOW limit screw so that the chain clears the INNER plate by about .5-1mm. 6a) adjust HI limit so chain shifts smoothly to big ring,but not so loose that it overshifts it. Better to just refer em to www.park too.com rather than muck most of it up.