Sorry guys, its been a long weekend and I havent had any time to get on here and answer any questions, I will try to do so now. We have been testing these all year and have approximatly 2000 miles combined on them. We have seen minimal wear on them. I cannot say they will not wear out, They are a wear item , as are wear bars, hifax, scratchers, but the benefits to these are phenominal. The amount of snow these place on the hifax and coolers is amazing. We think on normal snow conditions these will last 2 to 3000 miles or more.
These are only scooping up the snow that the wear bars are disturbing, and placing it in the suspension. They are not touching the ground when the sled is setting on concrete.
We have never have them catch a trailer ramp while loading.
I suppose they could be dangerous if you role your sled over, but so is the track, the ice scratchers, the carbide runners, ect....
These are a "install correctly and forget they are there" scratcher. And the instructions are pretty detailed on how to install them correctly.
Hope this helps, Keep asking questions and I will try to answer them. We will try to get more pics and video up when we can.