I have a compact double.
When shifting from the small to large ring the chain sometimes does not catch. After a couple seconds of pedalling or trying to shift up again, the chain moves. I have a feeling the derailer is not moving far enough to the right.
And then sometimes when down shifting from the large to small ring (usually happens when I'm going downhill for some reason) the chain comes off the rings. I think it's going too far to the left.
So overall I think the front derailer is too far left... such that shifting up sometimes doesn't catch... and shifting down sometimes drops the chain. I think this is a reasonable diagnosis. But what can I do?
Thanks for the help! BTW, finally donated, does it usually take time for the red star to appear?