This is what is interesting about this site learning what goes on in different areas. I was a foreman for a large company for 7 years and been in and out of the business since 1997. We never ran without the guards, I can't remember one breaking off. I've not noticed any other LCO in the area running without the guards either. There was no reason we left them on. I always figured that was how the head knew how much line to let out ect but never really gave it much thought. Somehow up here in Maine we have all survived! Lol When I get a 2nd back up trimmer, shopping now, Im going to give it a shot!