Front mech help please

[BigonaBianchi]

My chain is rubbing against the front mech when the rear mech is on any of the four biggest cogs.
I expect it to rub a bit when on the biggest rear cog, but not four of them.
I've had a good play with the cable tension and the limit screws, but the problem remains.
The clearance between front mech and top of chain seems right, about a coin thickness, as does the mech angle when I look down on it.
To my mind in seems like the mech needs to be moved closer to the frame, is that possible?

Any help appreciated.
Cheers.

 

[mrandmrspoves]

My chain is rubbing against the front mech when the rear mech is on any of the four biggest cogs.
I expect it to rub a bit when on the biggest rear cog, but not four of them.
I've had a good play with the cable tension and the limit screws, but the problem remains.
The clearance between front mech and top of chain seems right, about a coin thickness, as does the mech angle when I look down on it.
To my mind in seems like the mech needs to be moved closer to the frame, is that possible?

Any help appreciated.
Cheers.

Assuming that you are not committing the cardinal sin of using large crank + large sprocket, and assuming that the problem is new, I would try disconnecting the front derailleur cable and check it is not snagging, then giving the front mech a really good clean as it may be partially seized. The front mech should automatically retract towards the frame under its own spring tension - but grit and debris can often limit its full return. Work it backwards and forwards while spraying liberally with penetrating oil and keep trying to push it a little further towards the frame as you do this.

 

[BigonaBianchi]

thanks..

well yes i am riding on big crank smaller rear cogs sometimes...but rubbing on th ebig rear cog is normal...but this is on all of the four bigger rear cogs ...thats new and not normal. I'll try the penetrating oil thing...many thanks

 

[Biker Joe]

A good site I use occasionally is:-http://www.parktool.com/blog/repair-help
Have a look there for setting up a front mech. ( loads of other stuff there too) Clear instructions.

 

[BimblingBee]

Is it a triple or compact/double?