Check under the fenders after your next ride. If you see they're really caked with mud, then they're working. I found that my fenders didn't really catch much mud anyway, but I knew once I cut them they'd be gone forever. So, I just cut them down a little at a time right now they're the same shape as the stock ones, but they're about half the size. I think it looks damn good, and it doesn't look like every body else on the block. If I decide I want them gone later, I can chop em, but, once they're gone, they're gone. sorry for the long read.