Joined: Jan 2010
Posts: 9,813
Likes: 1,790
From: Northern California
Bikes: Cheltenham-Pedersen racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.
The only issue I ever had with using HG chain on an original IG-equipped bike was a tendency for the chain to derail itself off of the big ring toward the inside, down to the middle ring.
This wasn't an adjustment issue, and I fixed it with some subtle modifications to the IG big ring's teeth, and which solved the problem for me.
The problem tended to occur as the chain was shifted toward the larger cogs, something that the original all-IG setup tolerated gracefully.
I noticed the text "For use with IG chain only" on a tiny label on the large chainring.
IG chain is still available.