how to adjust Front Derailleur

[ronan_zj]

yea, I need help on this front derailleur adjustment.
I know there 2 two screws, L and H there, but I still can not ajust to the biggest ring. sigh~~~ and even on mid ring, there is no clearance between my chain and outter derailleur.

[eastside]

1st. Undo cable, then set the L screw for the small chainring. You want about 1mm of clearance between the chain and the der. cage. Then pull the cable tight and tighten pinch bolt. Shift to middle chain ring then to large. If it wont go into the big ring then loosen the H bolt so it will allow the der. to swing up that high. You don't want to loosen the H bolt too much because the chain will get thrown off the big ring. It all about the fine tuning. Hope this helps.

[ronan_zj]

should I adjust the mount higher?

[eastside]

You want the cage about 2mm or so above the big ring.

[free_rideman]

Yes, if it isn't adjusted correctly. There should be enough "upwards" clearance so that when the derailleur shifts from big ring to small ring, the chain isn't pushed into the big ring's teeth, instead it is pushed off its intended course from behind the teeth. Just fiddle with it. Start with height of the derailleur, and just shift and check for that one thing. Then do the limit screws, and then play around with cable tention so that your trim lines up in the right places.

[bidaci]

The Park Tool website has an excellent how to section on adjusting the derailleurs. (http://www.parktool.com/repair/readhowto.asp?id=75)

[justfuzzit]

The screws are limit screws which just stop the derraileur from going too high up or too far down. Adjust the L screw so it is just not touching the chain (the chain should be in the small front ring and big rear ring) then bring the derraileur up to the big ring, pulling it by hand out as far as it will do (shift into the small ring in the rear) Same thing here accept with the H screw. Dont adjust these with tension on them.

As for cable tension which is what makes it shift correctly and you dont have enough of. Just stick the der. in the small ring and release the cable. Now pull the cable down while running behind the bolt that tightens it down and have it farily tight. tighten the bolt. Now try shifting it. If it still isnt going up, you need a little more tension by usually just twisting the barrel adjuster (if there is one) or re tightenning it through the derailleur...

[ronan_zj]

Thank for all of your helps.
I will try it later.