I have found an issue with the hardware supplied by the ACE Engineering tubular fenders http://www.aceengineeringandfab.com/...ders_p_32.html
The mounting hardware I recieved came with aluminum nutserts for 1/4x20 mouting bolts. I have found that while the fenders themselves are very stout and can take alot of abuse without bending them at all, the fenders can fairly easily be pulled from the body.
I hopefully have fixed the issue with better mounting hardware after one of my fenders was almost pulled clean off. I saw the price for the fenders has gone up quite a bit since I bought mine. ACE may have upgraded the hardware since I bought these back in 2012. If so, this if for the guys that bought these before they did. If not, I really think they should.
I would honestly take the extra step if you havent installed these yet and would go this route if you have found yourself in the same boat I a was in.
I replaced the smaller aluminum nutserts with steel 5/16x18 nusterts. These are much stouter and will hopefully advoid the same issue. This is the same size that are on my body mounted JCR sliders, and I have hit them much harder than I hit my fender and they are still intact.
All total I had to replace 5 of nutserts in one fender and in the last photo you can see the difference between the two.