Originally Posted by dnuzzomueller

In theory yes Cross chaining is bad. (And in practice it does shorten chain life). I can relate with you experience though because I have one bike with a long cage rival compact (50/34, 11-32) and one with Force (53/39, 11-28). In a flat scenario I almost always find myself cross chaining the 34 in the three smallest cogs, not really the best move. On my 39/53 I find myself much more apt to ride middle of the cassette with the 39 and I kick the 53 into gear when I am really cruising, on the 50/34 I find myself shifting into the 50 much more(Not a good thing IMO) then I shift into my 53 on the other bike.

Moral of my soap box: You would probably be better off asking about swapping the 50/34 into a 38/52 or 36/52 and going with a cassette that does an 11t gear (I personally recommend a 11-25, I find myself rarely using anything larger then 25 and I DO go up hills every now and then). Before you buy I would recommend asking about swapping out those chainrings if possible. Or at least swapping your 34 to something a little bigger that is what I would have done.

Originally Posted by ColinL

nah. the FD shouldn't need any adjustment just changing the cassette. it will need adjustment after the cables stretch.