Adjusting end point on Shimano front derailleur

[x70]

Hi,
i have a Shimano Ultegra 6600 Double chainring and the derailleur cage is touching the chain when i use the smallest sprocket and any of the two chainrings. I read that to move the outer end point i need to adjust the inner side screw. I tried but the cage does not move. As a test i have tried also the other end point screw but nothing happen. Do you think it's a sign that the screws dont work? Do i miss something else here? For example can i only adjust the end points if there is no tension in the cable?
Thanx,
Teo

PS: Shifting works perfectly, it's just that whenever i use the smallest sprockets the chain scratches the front derailleur

 

[rparedes]

Hi,
i have a Shimano Ultegra 6600 Double chainring and the derailleur cage is touching the chain when i use the smallest sprocket and any of the two chainrings. I read that to move the outer end point i need to adjust the inner side screw. I tried but the cage does not move. As a test i have tried also the other end point screw but nothing happen. Do you think it's a sign that the screws dont work? Do i miss something else here? For example can i only adjust the end points if there is no tension in the cable?
Thanx,
Teo

PS: Shifting works perfectly, it's just that whenever i use the smallest sprockets the chain scratches the front derailleur

Are you trimming properly?
It sounds like the limits are not set correctly OR the tension on the cable is too high. Loosen the cable some and then try the limit screws, then using your hand to pull on the cable (use a towel to grab the cable or you cut yourself), see how far the cage moves.
You want to set the upper an lower limits at their max so that no rubbing occurs but it doesn't throw the chain. It's better to do it by pulling on the cable by hand to move the cage than using the shifter.
look here:
Park Tool Website

 

[kdelong]

Is the front derailleur positioned correctly? If you have a clamp on derailleur, it is possible that it is turned too far to the left. Loosen the clamp and slightly twist it to the right so that the inner cage plate is parallel to plane of the chainrings. If it is already parallel, then you may have a bent FD cage. In this case, just bend it slightly away from the chain. Not that many years ago, it was discovered that bending the outer cage plate often improved shifting, and what you have may be one of these adjustments gone too far.