I used 1.5 mm aluminum sheet. I have worked in the steel industry for many years, so i used industrial machinery to help, but it is not necessary. Cut a sheet that is adapted to the handlebar width (600x300 in my case). I also cut off the lower corners for design's sake. Shaping it to the radius of ~150 mm. Can send a sketch or else if you want.
Bo Enedahl WiseSolution View Instructable »
Easy-build Bike Trailer