Derailier Drama

[NeoCaesar]

Okay, so I'm getting pretty competent with the basics but there is just one thing that eludes me -eradicating cross chain rub. I have my front derailier cable adjustments down perfectly (instant shift up and down) but I cannot for the life of me lose the cross chain. My question is if I have adjusted the tension and it still occurs is it now a matter of derailier position?

Thank you in advance for your wisdom. A part of me wants to change the derailier as the front is Sora, rear Tiagra and the rear has worked like a dream. Either way though I will need to get to the bottom of this before I do.

 

[RecordAceFromNew]

Assuming your front mech cages are parallel (looking from the top) to the chain rings and there isn't much more than a 2mm gap vertically (when looking from the side) from the large front ring when you are on it, and assuming you don't have the wrong bottom bracket / chainset combination (which would have given rise to a faulty chainline), bent cage or such like, the basic way and objective for adjusting the front mech is to:
1) Set the H limit screw so that the inside of the outer cage is 1mm from the chain when you are on large front small back
2) Set the L limit screw so that the inside of the inner cage is 1mm from the chain when you are on small front large back
3) adjust the cable tension (using the front cable adjuster) to centre the cage (when looking from above) over the middle ring (if you have a triple chainset)

If you still get cross-chain rub after achieving the above 3 steps, then it is unavoidable - in that you would either get chain rub when you are in the gears you should be using (i.e. small front large back or large front small back), or chain rub when you are in the gears you shouldn't be using (i.e. small front small back or large front large back) which will be what you are getting, and hence no big deal.

Hope it makes sense.

 

[Grizzly]

I suppose the question is, is it rubbing on the outside or inside edge of the derailier? Adjusting the two wee screws on the top of the derailier can be adjusted to prevent rubbing. It should be noted though that the chain should never go from the inside front ring to the outside rear ring and vice versa, you'll almost always get rubbing if you do.

 

[NeoCaesar]

1) Set the H limit screw so that the inside of the outer cage is 1mm from the chain when you are on large front small back
2) Set the L limit screw so that the inside of the inner cage is 1mm from the chain when you are on small front large back
3) adjust the cable tension (using the front cable adjuster) to centre the cage (when looking from above) over the middle ring (if you have a triple chainset)

Sorted -I had used the limit screws but not while the chain was on the extremity of opposite gears -kinda obvious really... That should fix it right up.

I suppose the question is, is it rubbing on the outside or inside edge of the derailier? Adjusting the two wee screws on the top of the derailier can be adjusted to prevent rubbing. It should be noted though that the chain should never go from the inside front ring to the outside rear ring and vice versa, you'll almost always get rubbing if you do.

Not sure where it's rubbing. I am aware that there will be a certain amount of cross chain rub the further across the gears are. Probably start getting rub 3-4 rings away from the outer, I would be happy with 1-2 I think.

I'll let you know if I can get it a bit better.