TOPIC:

Alright Trike Builder there's your challenge. Get'r Done!!

There's a reason why the Equalean went out of business, as well as those Piaggios. On the Equalean, the multitude of articulated joints (eight, to be exact) had to be so robust to prevent slop and flex that it would have made the rig way too heavy to be practical. They tried using the lighter ones, but they were too prone to going into harmonic oscillations from the flexing.

Similar situation for the Piaggios. The mechanisms are just too complex to give solid control. Besides, there are other engineering facts that come into play here that negate the need for two wheels instead of one anyway. Basically, each wheel has half the weight on it, giving much less traction than one wheel with more weight. It doesn't really work out to be a 2:1 ratio, but close enough that it sure doesn't warrant all the complexity (spelled $$$$$) of that two-wheeled front end.

Kawboy, was that Piaggio harder to steer?

Anyway, I've retired from engineering and now just want to let my mind play around with mundane things like copying what others have done successfully, but with a little bit of styling change.

"You're not a speed demon are you??". Oh, only up to about 150mph! But, not with a street sidecar rig. I had a very brief 6 race sidecar period where I filled in for a racer who had broken his neck in a crash (he survived after a year of recoup!), but was leading the points that season and wanted his rig and his monkey (his girlfriend, actually!) to have a chance to place in at least the top five. That's where I got my experience with 150mph runs. I quickly realized that I had replaced a guy who had BROKEN HIS NECK doing just what I was doing! So, although I sure got hooked on the thrills of it all, reality set in at the end of the season. Oh, and we ended up second overall for the season! They really aren't all that hard to learn to drive, guys! And, Kawboy, they are a WHOLE LOT OF FUN to build and maintain!

trikebldr wrote: Kawboy, was that Piaggio harder to steer?

Anyway, I've retired from engineering and now just want to let my mind play around with mundane things like copying what others have done successfully, but with a little bit of styling change.

The hard to steer question. No quite the opposite. I think you would probably scare yourself before you outdrove that bike through a turn. I pushed it beyond what I considered was my riding ability and not so much as a churp or wiggle from the tires. I was impressed.

As for retiring from engineering - If you loved your job then you can never retire from engineering, you just have to pay for all the development yourself. As a mechanical maintainer in the nuclear plant I had engineers coming to me for engineering answers and I would have to build the item and then they would reverse engineer what I built and rubber stamp the drawing and have it put in to the controlled documents. Had I been an engineer, I would have made half the money I made as a millwright. Sad to say, but the truth. Truth be known, I should have gone to university for engineering, but there was no money for me to do so.

There are quite a few K series BMWs that have that type of setup, some the sidecar wheel tilts with the bike and some where the bike only. Cant find any pics ATM but will continue to look.

Well, speaking back on topic with more of the thought process of this project, mine will have the "usual" rigid arrangement of the bike being tied solidly to the 'car rather than any leaning capabilities. I really liked the ride and handling of my '83 Voyager tied to my old Spyder that way and expect the new rig to be identical. If I want the feel of the lean, I can quickly detach the 'car to ride solo. Or, better yet, get another bike for solo work.

Somebody mentioned a sub-frame to go under the 'car. A good majority of the 'cars out there do have this arrangement, but Motorvation pioneered the monocoque construction method of using the 'car's body as the frame (called "monocoque"). They embed four steel plates in the fiberglass; one in the floor under the seat area, one in each side next to the passenger, and one in the partition behind the seat back. There is no framework other than this. The two lower struts that connect the 'car to the bike slip through tubes with clamping collars that are welded to these side plates and cross under the seat bottom and just in front of the seat. The two upper struts have clevis connections that bolt into these same side plates. The five suspension links (on the older versions of the Spyder, which I prefer!) have their anchor points for their heim joints bolted to the bottom steel plate and the right side plate. The top mount for the coil-over shock is also bolted to the right side plate. The plate that goes across the seat back is there to tie the two side plates and the bottom plate together for rigidity instead of just using the fiberglass for this. The Spyder's lateral strength is derived solely from the plate in the seat back. The final result is a very rigid structure without a lot of weight from a sub-frame.

Instead of using these heavy plates embedded in fiberglass I will be using heavy-walled, cross-braced tubing to create all of these anchor points. Strategically located tubing and "edge-loaded" sheet bracing will create a rigid structure just as well, if not stronger. Certainly not as cheap, though! Aluminum isn't cheap anymore. Using tubing to outline the basic shape of the body itself will also add tremendously to the overall strength and rigidity while keeping weight down. The aluminum skin being welded to this tube framework will also add a lot of strength, but even more rigidity!

Just to add a bit of eye candy, here is the 'car that inspired me to use the tubing method to give shape to the body. This one has the body panels bolted inside the tubing on small tabs, though. BTW, this is a totally custom two-wheel-drive rig! The "bike" and sidecar were designed as a unit. I love working with aluminum, and this rig just told me to "DO IT!". Isn't it beautiful?

Thanks for that last photo ,trike.......I had to STARE at that for awhile ....to take it all in !......tony