Joined: Aug 2010
Posts: 12,730
Likes: 2,106
From: Madison, WI
Bikes: 1961 Ideor, 1966 Perfekt 3 Speed AB Hub, 1994 Bridgestone MB-6, 2006 Airnimal Joey, 2009 Thorn Sherpa, 2013 Thorn Nomad MkII, 2015 VO Pass Hunter, 2017 Lynskey Backroad, 2017 Raleigh Gran Prix, 1980s Bianchi Mixte on a trainer. Others are now gone.
As you already noted, chainstay length is an issue. I go to the grocery store on a 1990s vintage MTB and my heel clearance with grocery store panniers is terrible.
I have toured with a friend that uses his mountain bike. He is quite happy with that bike for touring but his panniers had permanently installed hooks to attach to the rack, he had to remove the rivets and move the hooks to get the heel clearance he needed.
I tried three times to attach a photo, but the web site was not cooperating.