Thanks for the heads-up, Andy; always good to see more options out there.
There's little really new in bicyclig, but one of the earliest
modern examples of this design is the Blue Sky bicycle cart, originally developed here in Eugene by Gary Hale, a very nice fellow of 35 years' acquaintance. They're still available here:
http://www.yellowjersey.org/bluesky.html ...and direct, here...
http://blueskycyclecarts.com/ A little history on them:
http://www.halebikes.com/history/index.html and Gary'shere:
http://www.halebikes.com/index.html He doesn't do much building anymore, but his fillet-brazed customs were works of art in the late 1970s-early 1980s, and were all created using human- and pedal-powered tools including milling machines and lathes of his own design. Go to the Photos section for <ahem> "vintage" touring pics showing things as they were when I started touring:
http://www.halebikes.com/pictures/bike1776/index.htmlCarts of this sort that place their load and fulcrum on the seatpost have little effect on the ride of the bicycle, but do have a couple drawbacks,
depending on how the design is executed: 1) They
can block access to top of the rear rack (if present), and 2) they do have some quirks in how they trail on tight corners. Nothing that results in bad overall handling, but in my experience they can clip a curb in tight turns and it is a bit hard to judge how they will pass between bollards if there is a curve leading through them.
This design is great for handling really heavy loads, and seems to avoid the quirky bike handling that can sometimes result from attaching a heavily-loaded trailer to the rear axle of a bike with very light rear stays. On the other hand, trailers of this boom-type design
almost always have two wheels. If you go off-road or on very rough roads, this means you have a three-track vehicle and it can be awfully hard to miss a pothole or avoid big rocks. If the bike misses, it is almost a sure bet one of the trailer wheels will catch it. I prefer single-wheel trailer myself for my rough/off-road touring, though I have built a couple two-wheelers that work very nicely for smooth-road touring and getting groceries (they use weatherproof storage boxes and predate the BicycleRevolution trailer that was also produced locally).
Boom-type, seatpost-secured trailers are great for heavy roads and relatively smooth roads, and really shine in that application if you need to haul kids, heavy crates, or gallons of milk to market. It is another case of "horses for courses". Thanks, Andy, for the trigger to my Blue Sky memories!
All the best,
Dan.(...who thinks "Nothin' but Blue Skys [sic]" could have been The Bike Trailer Song in Eugene, Oregon in the '70s and '80s)
