Possible, yes. Practical, no. Steering geometry, extreme tire wear, extreme steering effort and the fact that it would classed as an automobile in most places due to the four wheels are just a few of the obstacles to reasonable efficiency of usage. For a novelty, it isn't too hard to assemble such an anomaly but I think it would take some tall engineering to make the beast run down the road safely with any degree of comfort.
Lonnie
One thing that was not mentioned as that sometimes people simply forget that the rules of law in the USA are not always the same in all other countries. In other words, there are other places in the world where sidecars don't have the same rules or constraints to follow as we do. I see pics all the time of Indonesia, Africa, India, Philippines, China and other nations where many things about sidecars defy the tradition here, in both the application of laws and what is considered to be safe or roadworthy. Most of those machines and the way they haul people or other items would make most of us outright cringe in horror, but it is a way of life for them and the feelinng is not really the same. From hauling things to hauling people, they zoom to a different drum and always remind me that the US is not really the only place in the world where things happen, even in the world of sidecars. My son-in-law was in China this past week. His stories are always amazing as to what they ride and how. At times I think we should be so lucky and then at times I think that maybe we shouldn't be, after all. 🙂
Pat Huey - 7/30/2011 4:09 PM
One thing that was not mentioned as that sometimes people simply forget that the rules of law in the USA are not always the same in all other countries. In other words, there are other places in the world where sidecars don't have the same rules or constraints to follow as we do. I see pics all the time of Indonesia, Africa, India, Phillipines, China and other nations where many things about sidecars defy the tradition here, in both the application of laws and what is considered to be safe or roadworthy. Most of those machines and the way they haul people or other items would make most of us outright cringe in horror, but it is a way of life for them and the feelinng is not really the same. From hauling things to hauling people, they zoom to a different drum and always remind me that the US is not really the only place in the world where things happen, even in the world of sidecars. My son-in-law was in China this past week. His stories are always amazing as to what they ride and how. At times I think we should be so lucky and then at times I think that maybe we shouldn't be, after all. 🙂
Bingo.
Different places, different rules.
And I'll add: different people, different views.
And speaking of which, here's some more different:
BONUS: The most environmentally friendly set of tires I have ever seen:
Dual sidecars? Why not? While I'm not interested, whatever floats somebody else's boat is no business of mine.
How about quad sidecars? Here's one...in a cartoon, anyway:
Well, I'll move along now; do carry on...
Sometimes I can't see the forest form the trees. This talk about a double sidecar is a mute subject. The platform for such a contraption has been driving around the street of America for some time, and they number in the hundreds. There called Voyager Convertible kits. There not a trike, or a motorcycle. They have four wheels and make it posable for people having problems holding up there motorcycles to ride without the threat of falling over. I have been seeing they units for a few years and never thought about there relationship to whats been written lately. It all came to light this morning when taking a ride up to the local service area a few miles from my home. It's on a road at the base of the mountains called the Cherokee Scenic trail. It's a starting point for many headed for the Blue Ridge Parkway. On any Saturday morning in good weather, as many as fifty to one hundred motorcycles can be hanging out. As I pulled in I saw what I had seen many times before, and that's when the light went on. There parked at one of the gas pumps was one of the Voyager Convertibles. I walked over to the gentlemen pumping gas into the contraption and introduced myself. I never mention anything about sidecars. I have found over the years that the general public is not interested in a sidecars rig unless your on one, and they ask. So why bring it up. We chatted for a while, and I asked him such questions as to how easy was it to drive. Did he get poor tire wear, and did he get pulled over by the cops every time he took it out. I was told that it drove with little to no effort, and that there was no abnormal tire wear. He looked at me kind of strange when he mentioned that the police never bothered him. I didn't want to look like a complete fool so I didn't ask if it was legal to drive. These where all questions that some had brought up relating to the double sidecar. I then mentioned that if a fellow was to remove both saddle bags and fabricate a fiberglass body on each side there would be enough room for a child in each area. He came back with " or a dog and some luggage".
It looks like all this talk about legality and driving difficulty was for not. It's not 100% of what has been talked about, but mechanically it's the same.
I came home and did a Goggle search and found Voyager Convertible Kits. They have a dealer search and I found many dealers in the state of California along with others in the West. It seamed that most of the venomous discussion was from that area of the country. I beleave they have been proven wrong on every point.
My thought on doing a design exercise on this subject has died a very quick death. May the double sidecar rest in peace.
Later, Johnny Sweet jsweet450@yahoo.com
Now that was a pertinent, informative post.
Despite the aformentioned trees, you just made the forest perfectly visible to even the least observant among us. Which is often myself, I gladly admit. 
Thank you, Mr. Sweet.
