Hooking a 1979 Vetter Terraplane to a 1984 Voyager

This may be a little (LOT!!) long, so I will break it up into smaller sections of how this build went together.

This may be a little off the normal, beaten path for this forum, but there have been a few sidecars shown here, so I figured I would show how I mated one to my Voyager. The sidecar and the bike are old enough now that nobody makes mounts for them. I had to make up my own, using some of the inspiration from Caddypat's (THANK YOU, Pat!) pictures and how a previous sidecar was mounted to my old '83 Voyager back in the mid-'80's.
The Vetter Terraplane is a three point mounting system to allow for on-the-fly lean adjustment for road crown compensation. That works well for lighter-weight bikes, but not for a 960lb Voyager. I decided this rig needed a four-point mounting system. Lean angle will be controlled by an air-shock on the sidecar and an on-board air pump controlled by the pilot. The Terraplane has a roomy trunk behind the seat to carry a compressor, as well as a larger, automotive-sized battery and a heater to blow warm air under the seat and across the floor area.
To get started on making the mounts the bike had to be set up at the correct starting lean angle of 2 degrees away from the sidecar (to the left). Fortunately, this bike already has a trailer hitch, so I made up a support bar to bolt to the hitch frame. This bar (see first pic) has two 1/2" all-thread rods with small steel feet that I used to adjust the side-to-side lean of the bike. No center or side stand was used on the bike after the bar was adjusted for correct lean. The bike stayed in this position through the whole process of fabricating the mounts.
The next step was to set the sidecar up on a dolly (see second pic)to get the correct fore/aft and side-to-side levels and ride height. I needed the dolly because it would need to be moved close to the bike and away from it often to get in there to work on it and do trial fits of parts. It also allowed me to remove the sidecar's wheel for cleaning and rebuilding without losing the sidecar's positioning.

The next step was to fabricate some basic parts to be used in the struts.
I made up some two-bolt clamps that would allow up/down and fore/aft rough adjustments on three of the struts. These clamps are made from three parts (first, second, third and fourth pics), welded together, then saw-cut to allow for clamping movement. The two bolt bosses were made from solid round bar stock, drilled on a lathe for 3/8" grade-8 bolts and nylok nuts. Then they were milled with a flat to help mate them to the clamp tube. The clamp tube was made of .157"walled tube with a slightly smaller ID than the tube it would be clamping around, so I bored them on the lathe to precisely fit on the tube plus .005" inch larger to accommodate the eventual black powdercoating that will be used. These clamp tubes were also milled with a flat on one side to help align them with the bolt tubes for welding. Of course, once everything was welded together and the saw cut made, the tube opened up just slightly. This is normal for seamless tubing when cut lengthwise. The hardest part of making these basic clamps was deburring the edges all around the welded areas after saw cutting.
Another basic part(s) that needed to be made ahead of time was to weld a threaded bung into the end of the tubing to be used on the strut itself (lower part of fifth pic). After welding, these pieces were chucked into the lathe and the weld bead turned smooth and the whole part "polished" with a flat-flap sanding disc (sixth pic). Any undercuts from welding were filled and re-ground smooth. This is a good way to check for any pits or hole in the weld.
The fifth pic also shows some of the parts I bought from my favorite hot rod parts supplier, Pete & Jake's. I got the 3/4" threaded bungs, and all of the strut-end polyurethane bushings from them. Some of those bushings were in plain tubes to be welded to strut tubes, but two of them were already on the ends of a 3/4" threaded stud and will be used for fine adjustment of alignment to the bike. These bushings are what they use on the suspensions of heavier hot rods and drag cars, so I figured they would be more than strong enough to handle this bike's weight in corners. Most mounting systems for sidecars use hard steel clevises that are put into a tight bind from fine tuning the alignment. They don't allow any movement. These polyurethane bushings are very stiff, but they do allow a tiny bit of misalignment of the joint. I've used these bushing on several hot rods and dune buggies before, and the ones on my current 26 year old buggy are still tight and clean. I also used them to mount the motor and trans in all of my hot rods. Pic seven shows one of the bushings taken apart to it's basic parts.

The next step was to make up the front-lower mounting point on the bike. Since the right crash bar over the engine's side cover has three struts that bolt to the bike's frame, I decided to use it for the base of the mount. I cut half way into the junction of the three tubes making up the crash bar and set the made-up bracket into the recess, then welded it in place (pics one, two and three). For now I painted the whole welded area black to protect from rusting until I can get the whole part re-chromed.
Then I fabricated the rear-lower mounting point. It uses a bolt that holds the right passenger foot rest in place, plus the bolt that holds the front end of the right saddlebag crash bar (fourth pic). Both bolts are large, 10mm fine threaded, so there is plenty of strength between these two bolts. Of course, longer bolts were used to accommodate the new bracket! And, once again, this bracket was painted black for now until I can get it chromed. It was made from a 1/4" base and side plates, plus some tack welded standoff tubes behind the base plate (pics five and six).

Now it was time to make the first strut to actually connect the car to the bike.
The first point to consider in aligning the two together is to place the car's axle about 15% ahead of the bike's rear axle. In this case it worked out to be about 10". This is not a terribly critical dimension, so I set the car in position and made up the lower-rear strut and welded it in place. The adjustment on this strut is vertical and in/out. My first attempt had to be completely removed and reworked because I neglected to consider just how the passenger footrest would fit and work (fold) once the strut was in place. I cut up the first footrest so badly to get it to fold up and fit, plus the strut made foot room a bit cramped, so I completely remade the strut and welded it in place. I am including pics of the first strut, then one of the cut up footrest, then the final strut and new footrest. The final one fits so much better and leaves plenty of foot room. All I had to do was grind a slight curve in the front edge of the foot rest to clear the strut tube. Much neater the second time around!
This lower-rear strut will be powdercoated gloss black. In the pic there are no gussets YET between the strut tube and the base plate that bolts to the sidecar frame. Those gussets are now there.

The front lower strut also needed a revision after the first try. It had a slight angle downward tilt forward after putting it in place. I cut it off and re-welded it perfectly horizontal. Since the lower-rear strut permanently locates the car fore and aft, the lower-front strut needed to be adjustable fore and aft. To allow for up and down adjustment, the tube can also rotate in the clamp. It can also be adjusted in and out by screwing the "lollipop" bushing end in or out to adjust for toe-in/out. You'll see the gussets between the strut tube and base plate welded in place in later pics. This strut will be powdercoated gloss black like the lower-rear one.

OK, so the two lower struts are made and in place. The sidecar is now solidly positioned to the bike. Now it needs to be solidly connected to maintain the correct lean angle of the bike. There will be front and rear adjustable length upper struts.
I started with the rear upper strut. It turned out to be the easiest.
The mount point on the sidecar was two small plates welded to the roll bar, but they were not positioned vertical! They were at about a 45 degree angle. This worked fine with the heim-joint (spherical rod end) on the end of the on-the-fly adjustable strut on the original system. That system was constantly in a loose condition to be adjustable while riding. I just hate those systems because they distract the pilot and also promote movement and serious wear on those parts. Every Terraplane I have seen had worn out heim-joints on that strut!
My strut had to have one bushing end welded on at an angle, so that meant machining that angle into the fish-mouth needed to mate up tightly to the tube clamp used. Not an easy task! It meant a tack weld, then check for fit, grind away the tack and adjust, then re-tack and re-check fit. Cut weld tack and re-adjust and re-tack, then check for fit once more. Finally everything fit correctly (vertical)(first and second pics). The rest of the strut was pretty much straight forward in construction, just like the other lower struts. However, the bushing ends on this strut had to be specially machined much narrower to fit into the existing brackets on the sidecar and to the limited space in front of the right saddlebag on top of the crash bar. You can see much clearer how much narrower these end bushings were machined in the third pic of the strut painted primer grey to prevent rusting before being powdercoated gloss black, too.
Oh, and I almost forgot that I had to make up that bushing "lollipop" on the inner end of this strut since it needed to be much narrower. I used a 3/4", fine thread, grade-8 bolt with a machined end welded to the narrowed bushing tube. The majority of the load on these upper struts will be the weight of the bike leaning on them under COMPRESSION (mostly!) in a left hand turn at higher speeds. In a right hand turn, the most load on them will be the sidecar and passenger's weight under TENSION (about 230lbs plus passenger's weight). That's actually pretty light for the part! The two lower struts were made MUCH beefier because they are under opposite compression/tension loads as these upper struts. Tension loads are the most important consideration since the bushings' shell is the weakest point in the connection.