HELP Please: front derailleur adjustment

jjbb

Hi

I bought my partner a 2009 Giant Avail 3 which had been ridden once or twice (although I couldn't tell....it's pristine). The chain appears to be rubbing right on the Front Derailleur (see pic) so I assume I need to adjust the Derailleur, however I don't know how to. I found a link to the Shamano technical document for the 2203 but I still can't figure out which adjustment will need to be made to get the chain to sit in the middle of the Derailleur???? Any help would be appreciated, thanks

http://techdocs.shimano.com/media/techd ... 625446.pdf

mikeq

If it is rubbing when on largest chainring and and largest sprocket at the back then it will rub, it will also wear down the teeth. Don't do this.

No adjustment is going to stop this.

Change down to smaller chainring

Mister W

As above..... but if it just needs a small adjustment then there will be an adjuster somewhere on the cable. It might be an in-line barrel shaped adjuster or one on the frame, at the end of the cable outer. Turn the adjuster a small amount and you should see the mech move.

John.T

Firstly the outer plate of the cage should be parallel to the chain ring. Yours appears to be out at the back. Adjust this by moving the mech round at the clamp. Put the bike in to the small chain ring and the big sprocket and set the clearance between the chain and cage inner plate to 1mm or less using the lower limit screw. Make sur the cable is slack at this time. If you do not know which is the low screw it is the only one that moves the cage when turned. When you have set this put the chain on the large ring and small sprocket and set the clearance between the chain and outer plate to about 1mm. Hold the plate against the screw by pulling the cable away from the down tube to tension it. Leaving the bike in this gear but letting go of the cable so it is set by the lever use the barrel adjuster on the down tube to set the mech so the cage has just moved back a touch from the top limit stop. It should not be hard up against it. Check all combinations of gears and if all works well that is it. If changing to the big ring is poor then slacken the limit stop a little, if the chain goes over the ring tighten it. Much the same for the small ring.
All covered here.
http://www.parktool.com/repair/readhowto.asp?id=75

le_grimpeur

I'd always go for the easiest thing to correct first, and in this case it is worth going over what has been written before, that is, the rubbing could be caused by having the chain stretched in a way that it should not be stretched. In other words if the chain is on the outer (or large) cog at the front, it should not be on the inner (or large cog) at the back, as a guide the outer cog at the front should only be used for the outer to middle gears at the back, and the inner (or small) cog at the front should only be used for the inner (or large) to middle gears at the back.

If this is not the case, here follows a brief and hopefully concise and comprehensible guide

There's two parts to front derailleur settings.

1 is the inner and outer movement of the derailleur. which is adjusted be the two screws, which in your photo are either side of the cable. They should be marked H and L. What these controls are the inner and outer movement of the chain. Principally they set the inner and outer limit of the chain - eg if your chain falls off either cog. The L screw is for the smaller cog, the H for the larger ring, and if it is not marked, usually the screw nearer the frame controls the smaller cog. If the chain overshoots the large ring, turn the H screw 1/4 turn clockwise. If the chain overshoots the small ring (and goes onto the frame) turn the L screw 1/4 clockwise.
Looking at your pic, and what you have written, I'd be inclined to think that the chain does not overshoot, and thus you'd be best to not fiddle with the screws. If it isn't anything to do with the chain being stretched, I'd be inclined to think that it's the position of the derailleur on the frame that is causing the problem. If you feel brave you can adjust it yourself, thus

2. Adjustiing the position of the derialleur.
You'd need to put the gears in its lowest position (small ring at front, biggest at rear) Then you undo the bolts holding the derailleur on the frame. You might get away with loosening it enough to slightly twist it, without having to really loosen it to a point where it could slip down the frame. So, you might want to consider marking the height position on the frame so you know where you can push it back to. However, you might have to then re set the limit of the derailleur using the method in 1.

Before you consider any of that, I found these video clips useful
http://bicycletutor.com/adjust-front-derailer/
http://bicycletutor.com/adjust-rear-derailleur/

Having written all of that, and it isn't a stretch issue, I'd take it to a shop if it is convenient to do so

jjbb

wow.....there's a lot to get my inexperienced head around. I'm going to print this off, sit down with the bike and try to figure it out and let you know how i get on. Thanks so far for the input.

le_grimpeur

yeah, I found it a bit much too, so I bought myelf "Road bike set up maintenance DVD". Thought I was turning into a bike nerd. Now it only takes me 2 hours to do what it takes a good bike shop mechanic about 15 minutes!

The biggest lesson I learnt was do one thing at a time! If what you do at first doesn't work, go back to where you started, oh and only make small adjustments and seeing if they work (OK biggest two lessons).

and let us know how you get on

joosed

There are a few videos on youtube explaining how to set up the front mech....here's one...
http://www.youtube.com/watch?v=ngm6dr-1na0&NR=1

Here's a playlist of bike setup and care youtubes....
http://www.youtube.com/watch?v=SkzvfCaI ... playnext=1