Chain rubbing

[Stantheman]

Is a bit of chain rub on the front derailleur acceptable.

 

[Smurfy]

No, it will slowly wear away the cage!

 

[Stantheman]

Hmm, might have to spend more time adjusting it, it's worse on the middle cog.

 

[wisdom]

On some systems you can trim the front derailleur to keep things smooth

 

[boydj]

It's hard to avoid at the extremes if you have no trim function, but, for the most part, there should be no rubbing.

 

[Stantheman]

No trim function, I will watch a few more YouTube videos and have a tinker tomorrow.

 

[Colin S]

If it doesn't annoy you too much and it isn't too bad it probably won't do much harm but with careful adjustment you should be able to get rid of it.

AFAIK you shouldn't really have the problem on the middle ring of a triple, it should only be an issue at the extremes of the gearing.



C

 

[Roadrider48]

Are there not two screws on your front mech? High and low limit adjustment.

 

[Stantheman]

There are two screws, but the rubbing is only bad on the middle cog.

 

[Roadrider48]

I would still say it's a fine adjustment of the H/L limit screws. It can be a real minute turn of one of them and it all falls into place.
Unless of course, your chainrings or front mech are bent.
Just another thought too. Are you running the chain from the middle ring to the extreme of the cassette?
IE: big cog to middle ring or small cog to middle ring. Thus creating a bit of cross chaining.

 

[Sterba]

Nothing terrible about a tiny bit of chain rub. If you adjust it one direction, it'll probably rub in another combination of gears. Shove some nice thick grease on the inside of the front derailleur and stop worrying about it. SRAM's answer (since they don't have electronic trimming) is to make the front cage wider at the end nearest the cassette.

 

[RecordAceFromNew]

Hmm, might have to spend more time adjusting it, it's worse on the middle cog.

The only adjustment that determines the position of the front mech at the middle front ring is cable tension - so turn the cable tension adjuster while eye-balling the middle cog directly from above until it sits right at the middle of the cage, you are then 99% there. Then try the extreme cogs at the back and see whether it still rub on one side or another, if only rubbing on the outboard side increase the cable tension (i.e. turning the adjuster anti-clockwise) a mite and vice versa.

Alternatively follow this to the letter.

 

[Stantheman]

Cheers for the advice, I think it is now a lot better than it was. I enjoyed messing about with it and learning how it works. Hydraulic brakes are next for a tweak.