all i know is what works for me. from the site you listed:loco said:You are cooler on pages, but you still don't know crap about cage lengths and tooth counts.
>A medium or long cage derailleur is necessary for FS bikes with lots of >chainstay growth/diminish, triple drivetrains, or doubles that use a cassete >with a wide gear range, like on mountainbikes.
my wife's Orange 222 is notorious for chain growth (long travel/single pivot design), has 7+" inches of rear travel, and uses a short cage der w/ no ill effects. go figure.