Having wide-open tires on the side of your trailer is dangerous. Especially when you’re loading and unloading the tow-behind. Terrible for your tires because anything sharp that might be on the back of your trailer (without a fender to stop it) can reach your tires and scrape or puncture them outright.

It’s dangerous for you, as an owner, because if you’re crawling all over the back of the trailer and you’re trying to balance on a tire while you’re adding a strap to your load, you can easily slip and fall. This can lead to injury to yourself, or damage to whatever you’re hauling. A properly installed fender (welded completely at multiple contact points) can give you a sturdy surface (and a surface with diamond plate style traction) to use during loading and unloading.