In a message dated 9/15/01 1:43:24 PM, firstname.lastname@example.org writes:
<< This was to allow a "racing" derailleur to wrap a large amount of chain,
like for a touring triple-chainwheel gearing system, without the long cage
that screams "touring derailleur". As far as I can tell, it didn't do
anything a long cage doesn't do; it was just to avoid the "stigma" of a long
cage on a "racing" bike. Since it was "goofy looking" and has the added
drivetrain friction of another pulley, it didn't "catch on".
There was a 3 pulley Dupar as well.