This design for a cargo sidecar for a motorcycle is so that I can use a standard motorcycle suspension to increase suspension travel over what most sidecars have.  I can source all of the parts for it on ebay.  The main difference is that instead of having a swingarm  sidecar suspension with a shock column near the axle, all of the suspension mounts and stress points are on the vertical wall (1 ft. x 2 ft.) just in front of the wheel.  This is why I designed it like a box which acts like a support beam for the suspension wall.  The cargo box is supported in the center of that box.  I designed it around standard 1-1/2 aluminum pipe 1.9" dia. and the walls 1/8" sheet aluminum.  The suspension wall is 1/4" 6061.  The front part of the sidecar is double walled, the cargo box being the inside wall.  This is for stiffness and to create a box corner to support the outboard suspension.  The basic dimensions are nominal on the centerline of the tubes.  That way the outside panels are even dimensions and are layed on the centerline of the pipes for welding.  That was so I could change the diameter of the tubes easily.  The dimensions of the cargo box were figured on the basis of 1.9" diameter for the frame tubes so if that was changed the cargo box dimensions would change.  The lids and doors are like a truck bed toolbox and need to be adjusted for latches , hinges and weather proofing.  The trunk on the front is like a truck bed tool box but might need a bumper.  I will deal with all the levers and wheels and stuff.

I'm looking for a ballpark estimate and I'm open to any ideas on design.  I chose the materials hopefully for availability but I checked and they can be had through Online Metals if your supplier doesn't.   

I'm available at  and if I haven't lost it 360-809-5962

Dave Eldredge  (The guy who brought the motorcycle swingarm over a year ago.)

If you click on the images below it takes you to a bigger picture and you can download them and print them out.