Honda VT700 Magna with Sputnik
Yesterday, another rig left my garage. Paul broke a leg in small accident on his Magna. His wife said that she wouldn't ride as a passenger on motorcycle, so he found that sidecars exist. Sputnik sidecar is my selection after few telephone calls with Paul. I had almost free hand in making a rig, the only requirement was not to modify the bike too much, as it may be sold separately in future. And my work was only the mechanical side and electric connections. Tub repairs, paintjob, upholstery etc - Paul will do himself. Both requirements (don't modify the bike too much and do only what's essential) are typical in Poland. Bike with modified or painted plastics is very difficult to sell, or you sell it for small part of its value. Paul will ride few months, then restore a sidecar in autumn, then My job will be mount and set up a geometry once again.
A rig itself is typical setup. Magna + subframe + sidecar + cable operated car's brake. The only modification in a bike itself, was cutting passenger's right footpeg to get additional mounting pint for subframe. But the footpeg can be mounted back with one 1/2" (12mm) screw after dismantling a subframe. I made all four mounts, because modification of original ones would take more work than making new. Last photo shows that both upper mounts are perpendicular in bird's view but this is nly the photo made from bad angle. Upper and lower mounts make two triangles, and upper struts make trapezoid in bird's view. As I couldn't modify the front suspension, I only moved a fork a bit in triple trees. Magna has big head angle (30 degs) so it's not the best for a rig. But whole rig rides surprisingly easy. It only required a steering damper.
As a steering dampers I use modified dampers from rear lift dooor from estate wagons. Making a bypass between both ends of damper's cylinder makes an ideal damper that don't give big resistance when you operate the steering bar slowly. But it becomes very resistive when you make short, fast moves. So it's ideal way to reduce a shimmy and not to disturb normal driving operation.
Longest work in whole rig war bending subframe tubes to omit right side panel on Magna. "DON'T CUT OR SCRATCH SIDE PANELS" was a rule of thumb. There were two ways - remove panel or make a sophisticated tube bending to not interfere between side panel and subframe. Fortunately a second way was possible, after a day of "dismount, bend a bit, mount" iterations.
Great Job!!! It's nice to see how resourceful folks are in other parts of the world. Keep up the good work, and reporting it across the ocean.
Later, Bud...
Nice Super magna! can you please give more info on modifying estate wagon tailgate lifters as a steering damper? I have a VW bus damper on mine but would like something a bit softer
Thanks
Rick.
You have to drill two holes, one near to both cylinder's ends. BEWARE! High pressure gas with oil and drill chips will escape! On one end you weld T-connector with one free hole for small diameter pipe (eg 0.2"/5mm ex. diam.) and one hole tapered. Then you weld thin pipe between non tapered hole in T-joint and the other hole in cylinder, to make bypass between cylinder's ends. The tapered hole acts as oil intake. Add some oil - be it hydraulic oil, gear oil - and bung with screw and brass gasket (or with brass screw). Oil type and quantity is individual matter. You have to test, add/remove and test again until you get your ideal damper. Also beware when welding. Cylinder's walls are very thin, about 0.015"/0.4mm. If you make too big welding bead, melt a bead through the wall (make some clutter inside cylinder) or add too much heat when welding, the plastic plunger head will melt, stuck or damage. Of course some oil will burn in cylinder so it's required to have really good ventilation.
Plunger has to be mounted a bit higher than cylinder to allow oil to gather in cylinder near mounting end. Press the bypass pipe with some pliers to minimize its cross section.
You may also make simpler version by just drilling one hole in cylinder (at the cylinder's mounting end), welding a nut to this hole and adding some oil. This version doesn't work so smooth (makes some resistance always) but worked years for me. It's much easier to regulate and needs less oil.
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