Originally Posted by giantcfr1
The hg73 appears to be the 105 9 speed.
Unfortunately it appears that the Ultegra Chain (cn-6600) is now only for 10 speed. Maybe you can find a shop with NOS Ultegra which is 9 speed compatible. If not, the hg 73 may be your only shimano choice.
http://cycle.shimano.co.jp/catalog/c...76&bmLocale=ja
steve.
The HG93 is also the Deore XT chain, so I'm sure it'll be around for a while. The reason there's now a separate Ultegra chain is purely because of the switch to 10 speed. I'm sure next year there'll be a 105 specific 10 speed chain, but the HG73 will still be around thanks to MTB (it's the LX chain).