Thanks. Yes, I've been using it for awhile now and have carried some heavy loads. It's served me well. It tended to get a bit wobbly, though, when the loads got heavy. Over the weekend I tore it down and added those stiffening struts and better bottom braces than what was there.

this afternoon I took it for it's first real test drive with these mods. I made a grocery trip. Loaded that blue duffel bag with a bunch of frozen foods. With that, tools and miscellaneous I know the load was not much less than 50 lbs, and maybe a bit more. Going home was a rather long, moderately steep uphill. Most people on bikes end up walking it, but I ride it and did so today. I could definitely feel the load. It was noticeably heavier than usual. This means, of course, that there was some "rocking" of the bike. But that rack didn't move a millimeter.

Looks like it might be a success.....