Joined: Nov 2006
Posts: 19,810
Likes: 597
From: NJ, NYC, LI
Bikes: 1940s Fothergill, 1959 Allegro Special, 1963? Claud Butler Olympic Sprint, Lambert 'Clubman', 1974 Fuji "the Ace", 1976 Holdsworth 650b conversion rando bike, 1983 Trek 720 tourer, 1984 Counterpoint Opus II, 1993 Basso Gap, 2010 Downtube 8h, and...
Archie, I'm sure we'd all love to see photos of your bike!
I think you don't want tension, as such, on the leather. Tighten the nut only enough to take up all the slack, so it doesn't rattle. If you put actual tension on the leather, it will tear at the rivets. I had a nice Brooks Pro that I (or someone) ruined this way. I got it used (but pretty new) and may have tightened the nut at some point between 1980 and 1985, and tears started appearing in the mid 90's; took a while, but clearly the leather was under too much tension.