if you need one, make one out of thick stock......sheetmetal isn't gonna do much more good than the stock fender.

a few guys have made some over the years.......you can do a two-peice with bolts on the insides of the tubes, but they tend to open up on the outside.

or you can do a one peice that slides over the top of the tubes and goes around the outside of the tube, then to the inside and has a bolt that pinches the bar around the tube.