I used 1/2 inch galvanized pipe to make mine. Pretty simple. Cut to size, one 43 1/4 inch and one 46 inch, carefully lined up and drilled my holes for the U bolts, painted the pipe black, then glued on some rubber chair feet to cover the cut ends. After getting it where I wanted and locked down I cut the U bolts off to about 1/4 inch and covered them with 7/32 inch rubber vacuum line caps. Total cost was about $25. Got a bargain on the basket too. Found it on Craigslist for $150 and it came with the locking tire carrier.
I may replace the plastic fairing on the front with one made from metal. The guy I bought it from said he had replaced 2 in the time he had it due to the rubber washers around the screws deteriorating and the plastic cracking on the bolts. A nice piece of aluminum cut to fit and painted black would solve that problem. Getting ready to make a run to the hardware store in a few to get new washers for it.