Front Derailleur Rubbing

gaffmaster

Hi all,

I'm a fair weather cyclist usually, but have upped my number of spins lately.

Came off my bike last week. My front derailleur is now rubbing loudly when I'm in the big chainring.

How do I adjust this? Do I need to tighten the cable from the shifter?

I'm a bit tentative to go fiddling with the front derailleur because previous balls-ups have taken hours of putting right.

Any help appreciated.

It's a shimano 2200 - Here are some pictures.

Thanks

bcmf

if you fell you may have bent the hanger that the mech hangs on.
But it looks like adjusting the limit screw will be enough.
I think on these its the top screw (but may be wrong And am tired and too lazy to google it) just turn the screw anti clockwise about half a turn and it should stop the rubbing.

Mycroft H

Have a read through this first. They are simple things. By all means do it yourself, but have a read through the link and familiarise yourself with the operation.

My guess is that the indexing is off and the front shifter is not puling enough cable and is causing chain rub. I would also check and see if the chainring is warped laterally (think a buckled wheel running side to side) and is causing the chain to rub on the front mech. This will only be on certain spots on the chainring, not a constant rub.

ashleey

You have probably just knocked it off line in your spill. Have a look from above to see that the cage plates are parallel with the chain when the chain is on the big front chain ring and one of the smaller cogs at the back, ie not crossed. Do this before fiddling with indexing or limit screws!

gaffmaster

Thanks for the replies.

I think it might be a combination of a warped chainring and an indexing problem.

The cage plates are parallel when in the biggest gear. There is contact along a vast portion of the chain that is in contact with the big chainring.

I have attempted to adjust the high limit, but there doesn't seem to be enough adjustment in it to get it out far enough.

When the front gear is shifted up to the big chainring, i can silence the contact with they chain by holding the derailleur out far enough by moving the gear lever - but it wont 'click' and stay there (hope that makes sense). Is this an indexing issue? I'm having difficulty finding out how to adjust this.

Cheers.

smacl

gaffmaster wrote: »

When the front gear is shifted up to the big chainring, i can silence the contact with they chain by holding the derailleur out far enough by moving the gear lever - but it wont 'click' and stay there (hope that makes sense). Is this an indexing issue? I'm having difficulty finding out how to adjust this.

This sounds like the cable is too slack and needs tightening. This can be done either using the indexing adjuster or resetting the cable. For the latter, try the following;

- Disconnect the cable from the FD
- Set the indexing adjuster about mid-way, so you can make minor adjustments when finished.
- Place the chain on the small front ring and big rear sprocket
- Set the low limit screw so the FD inner cage is almost but not quite touching the chain, about 1mm should work.
- Attach the cable so that it is taut as possible without moving the FD any more.
- Move the chain on to the big ring, smallest sprocket.
- Set the high limit screw so that the other side of the cage is about 1mm from the outside of the chain on the big ring.
- Use the indexing adjuster to make minor adjustments necessary.

Having the bike set up on a turbo is a great way to do this. Start with the brake of for set-up, and turn the brake on for testing / adjustment. (Guess who's been wasting too many hours pricking about with FDs of late).

torydiver

smacl wrote: »

This sounds like the cable is too slack and needs tightening. This can be done either using the indexing adjuster or resetting the cable. For the latter, try the following;

- Disconnect the cable from the FD
- Set the indexing adjuster about mid-way, so you can make minor adjustments when finished.
- Place the chain on the small front ring and big rear sprocket
- Set the low limit screw so the FD inner cage is almost but not quite touching the chain, about 1mm should work.
- Attach the cable so that it is taut as possible without moving the FD any more.
- Move the chain on to the big ring, smallest sprocket.
- Set the high limit screw so that the other side of the cage is about 1mm from the outside of the chain on the big ring.
- Use the indexing adjuster to make minor adjustments necessary.

Having the bike set up on a turbo is a great way to do this. Start with the brake of for set-up, and turn the brake on for testing / adjustment. (Guess who's been wasting too many hours pricking about with FDs of late).

Excellent description of how to set up the frond derailleur.....
Youtube has some decent videos aswell if you want to see it being done visually.........

ashleey

Follow the sequence on park tools website as above. If you bent a chainring in a crash I would expect a few bent bones as well. You probably just moved the derailleur on the frame. Check height clearance as well.

gaffmaster

Thanks for all the help.

I think i have it sorted? The cable tension/barrel adjuster was the key to it. Although I still might have a bent chainring.

This is a very clear video: