HI, last weekend I wanted to tow one of my bicycles to the shop and tried doing it with my xtracycle bike. It worked pretty well but I wonder if anybody else has tried this and has some suggestions.
I took a look at your write-up and photos, which were great. Let me compare your hook-up with how I've done it in the past.
You really tied that sucker in there good. That's great, but I think you may have done too good of a job. I imagine that the forces applied to the towed bike's rear wheel while turning were applying force to the frame, which wasn't able to move freely.
When I tow a bike, I only tie in the front wheel. It sounds like it might be too loosey-goosey, but it works great. It's a lot like a fork-mount rack but without the hassle of removing the front wheel. Just drop the wheel in the freeloader, pull the center strap over the wheel at about 11 o'clock, and pull the rear strap over the wheel at around 2pm. Then, and here's the key, take a bungee or cam strap and wrap it around your V-rack and the front wheel of the towed bike at about the 4pm mark. The front wheel is now 3-point mounted to your Xtracycle, and the frame and back wheel can track any way you want. The towed bike can now articulate as well, which may increase your cornering clearance. The only thing I typically add is a rag inbetween the towed bikes' fork and the V-rack to reduce the rub factor.
Here's a weird pano photo of my towing setup. http://twitpic.com/6nls3
I've used it to pull 'cross bikes, 29ers and one heavy, steel cruiser.