Ok, I use these on my 2009 KFX 450R and they have held up just fine. However, when I bought these, it said that they would fit my 2009 KFX 450R. However, they did not. I tried different ways to try to get the bolts to line up and they just would not. It may be because the 2009 KFX 450R comes with the oversized Renthal Fat Bar. However, Moose says that these will accept the oversized bars, but they really do not. I could not get it to work because the bolts only went through the clamp at an angle, which would not allow me to tighten them down. I literally had to take a drill and drill bit to wallow out the hole to make it bigger so that the bolt could go through all the way and I could put the nut on to clamp it down. After doing so, it did work and they have held up under very extreme racing conditions even after modifying the clamp. But they certainly did not work as advertised so I rate it as fair because they do hold up even after the mod to it.