Originally Posted by
Syscrush
One numbered groupset (e.g. 4400) is sold under different names in different years, so a new Tiagra could be better/newer/sexier than an old Ultegra.
it occurs very rarely, if at all.
3xxx - Sora
4xxx - Tiagra
5xxx - 105
5500 - 1999-2005
5600 - 2006-2010
5700 - 2011+
6xxx - Ultegra
6600 - 2005-2010
6700 - 2009+
6770 - 2011+ (electronic)
7xxx - Dura Ace
7800
7900
7970 (electronic)