A circuit of most of the Great Lakes would be a good ride indeed, Jim.
Like your acquaintance, I'd recommend skipping north of Superior, unless/until the gummint of Ontario invests in making the TCH safe for cyclists. (Don't hold your breath: I maintain a correspondence with my local Member of Provincial Parliament on the subject; he agrees that there's work to be done, which is at least a start, if some way short of actual action.) (Though it's better than a reply asking, "Why?") I did the north-of-Superior ride in the summer of 2013, the homeward leg of my ride across North America & back on my old-but-still-sound BMW airhead. I rode the north shore of Superior partly to check it out for a future cycling tour, partly to revisit a road last travelled more than 40 years earlier.
Wellll, even on a fast, comfortable touring motorcycle I didn't especially enjoy the ride: the scenery was magnificent, both beautiful and humbling (though I learned that yes, there can be one too many black spruce trees). But the truck traffic was a constant bother & threat, and the road simply does not have enough, or wide enough, paved shoulders for safe--never mind enjoyable--cycling. People do cycle this route--see some of the threads on crazyguy--but it's not for me.
But, the four other lakes would make for a great circuit. A friend here in Ottawa who grew up in Thunder Bay (at the lakehead) has done a splendid photo-essay on the lakes and their shorelines. Look for Sweet Seas, by Mark Schacter, published a couple of years ago. ("Les mers douces" was what the French explorers and voyageurs called the lakes before industrialization rendered them rather less so...)
