Originally Posted by
kayakkielbasa
Ok guys, thank You all for help.
I thnik all is clear. I'm only now thinking if I should get a Tourney or Sora, since some say that due to lower quality of Tourney derailleur the chain has tendency to fall off.
With my Tourney, chain has never fallen off the derailleur pulleys, but quite a number of times off the chainring, but that was also with previous Dahon compact derailleur as well. With short chainstay length, chainline (alignment of chainring to cogs) is critical. Thus, when at extremes (small ring/small cog, big ring/big cog), shifting fast to the other ring can sometimes drop the chain, but it also did that with a single chainring. The good news is that now that I have a double crank with front derailleur, putting the chain back on takes all of 1 second, just shifting the front derailleur to the opposite ring.
Buying better quality is never bad. I just don't know if any difference in chain drop.