Originally Posted by
Phil_gretz
Your problem stems from the derailleur's inability to take up the chain slack. I've seen this time and again. What seems "right" on the stand doesn't really work properly from the smaller front chainring.
I would recommend removing one link and trying again. You'll be surprised. Phil G.
Chain length has nothing to do with driving the bike. It could hang completely loose in the little/little combo and still drive the bike just fine. If the length was set to the big/big plus 2 links it is as short as possible. If the chain doesn't hang loose or cause the lower Rd pulley to swing forward slightly and apply some tension, then it's too long, but it would still drive the bike.