i made a mistake, the front is a sora. here is a review from someone else, perfectly annotates my problems.
"While it might be true that Sora shifts well when tuned up, Sora doesn't like to stay tuned. The rear derailleur never indexed completely accurately, even after multiple tunings by my LBS mechanic. This would lead to 'ghost shifts', or shifts that would happen whenever too much pedal pressure was applied. Sora's also low on features: the front derailleur only has three positions for a triple crankset, and the lack of a 'trim' means that many chain combinations result in deathly annoying chain-cage rub."