On a Brooks saddle (B66 in this particular case) there's a fat-headed bolt that runs vertically from the lower rails and into the adjuster carriage. If you look at the saddle from underneath, you'll see its head as the big round thing between the two long rails at the bottom of the saddle. That particular bolt on mine is loose. Is that supposed to be so? It's not terribly loose, but when I'm not on the bike it does allow the saddle leather and adjuster parts to bounce up and down somewhat. Is that something I could tighten by hand?

I know what you're talking about, and no, I don't think it's something you can fix by tightening the bolt. In fact, I don't even think it can be tightened. Cut a washer in half and hammer it in between the rails to snug it up a bit if it's bothering you.

I see-- has anyone else had this problem? Is it a major issue that would require a saddle replacement, or is this just a minor annoyance that doesn't worsen? I don't want to be riding a saddle that may come apart, though it doesn't seem that bad at the moment.

If it's a new saddle, bought new from a bike shop, I'd definitely take it back. If it's an old saddle off ebay or a used bike, I'd just deal with it somehow.

It's one I've been riding for about 6 years now, though it was bought used and appears to be around 30+ years old (though doesn't appear to have many miles on it). The leather is in good shape.

Lazarus thread time- but I've had this saddle sitting in a canvas sack for almost 3 years now. That front piece is indeed a smooth rivet with a taper to it. I just couldn't force anything in and have it stay. So I drilled and punched out the old rivet, fitted a bolt of the same size, then added lock washers, a thick fender washer, and bolted it together. I put some loctite on the bolt for good measure. I then reassembled the saddle. The saddle is from the 1970s I'd say.

Oh also- I did try to get the screw in the other way, so that the round head was facing downward/outward. However, the tensioner bolt passes so closely over that cradle that I could not fit the nut/lock washer combo in underneath smoothly.

Nice save, hope it works out for ya!