But, alot of it depends on several factors:
1. The "stock" steering geometry of the motorcycle
2. The weight of the whole rig
3. Width of the handlebars
4. Your upper body strength and what you are comfortable with.
5. The tires on the rig - knobbies have less friction on the road than street tires - which works both for and against you.
One thing that I do believe in - the attachment of the sidecar to the frame absolutely MUST be as stiff and strong as it can be.
Your top end and fuel mileage will drop considerably.
But everyone will want to stop and look/talk about it!
I'd like to take a few minutes and go through the stuff I agree with you on and, more importantly, the stuff ?I disagree with you on, and why.
1/. The stock steering geometry of the R65 is unsuitable, that said, the geometry can be disguised by altering the rear ride height, the amount of "lean-out" and even the fore and aft positioning of the sidecar relative to the motorcycle. The one thing you cannot change is the amount of flex in the entirely inadequate R65 forks. At the very least the best quality fork brace should be fitted, along with soem very much heavier than standard springs (the forks will dive more under brakes due the increased all up weight, fork dive will adversely affect the steering geometry).
2/. Agree, as light as possible having regard to rigidity and strength is very important.
3/. The object of correctly setting up a sidecar is to build it such that as little as possible effort needs to be put into muscling it about, I would only change the bars if I found the stock ones to be inadequate
after road testing and setting up.
4/. See above, the object of correctly setting up a sidecar rig is to mostly avoid having to exert force to make it do what you want.
At this point I should fess up regarding my experience in building and operating sidecars. I will ignore time spent simply riding sidecar outfits that were factory built, my greatest learning was in building a sidecar used to recover broken down motorcycles.
I spent some time before heading to work looking for photographs, as they are all way in advance of digital photography this means searching through a lot of old albums - I will post photos eventually.
Anyway, the outfit I built was based on a Honda CB500T (good power and dirt cheap at the time). The sidecar was in essence a flat bed tray approximately 1 foot longer than the CB500 and a little over 3 foot wide. Side car suspension was by way of a pre-fabricated light automotive trailer torsion arm suspension mounting a 13 inch automotive wheel and tyre.
The "learnings" along the way were:-
Whilst the mounting to the motorcycle must be strong and movement free, it also needs to be adjustable. To the end I used automotive suspension ball joints to attach the sidecar frame to the re-inforced bottom frame loop of the motorcycle, the re-in forcing beam extended somewhat aft of the rear suspension pivot and allowed the use of three ball joints for mounting, the middle was fixed rigidly and the foremost and rearmost ones incorporated lateral adjustment (relative to the motorcycle) so that toe-in/tow-out could be adjusted.
The reason balll joints were used was that it was always intended that the lean-out be adjustable and this was done but fabricating re-in forced uppper mounts on the motorcycle frame connected to the sidecar frame by way of large turnbuckles usually found in tractor implement attachments (in fact they were purchased from a 2nd hand farm machinery salvage firm), thus lean out could be adjusted in seconds by the coordinated turning of the turnbuckles. It was intended at the design phase to automate the turnbuckles by either using teleflex cables to a knob on the handlebars or by using electric gate controllers, but neither system was ever implemented.
Front suspension was initially stock CB-500T, but proved hopelessly inadequate with heayy loads and was replaced with a fabricated earles fork which used air adjustable automotive shock absorbers as the suspension elements. Initially it was intended to carry an on-board compressor to adjust the front suspension, but in practice a foot pump was found to be faster and was certainly much cheaper.
The rear suspension was replaced by a fabricated part and the frame pivots were re-inforced by fishplates (which proved inadequate in the longer term).
After initial fore/aft alignment, road testing was used to determine the correct amount of lean-out for the motorcycle, success was regarded as acheived when the outfit would track straight on level road with hands off the bars. The steering neutrality thus achieved allowed minor on-road left and right directional adjustments to be mostly accomplished by the use of throttle.
Continued next post.
