The mirror breaking off after a few drops and a final snag on a weak plastic tarp doesn't seem like a feature. The way that diameter reduction was machined means that it's going to break even without a collision. I think I'll dummy cord the mirrors to the bars just in case the other one falls off while I'm riding. I've been very happy with these mirrors and the repair once they fail isn't really a big deal when you're close to home. Dealing with it in the field would be a good reason to carry a spare base I suppose.