We put fenders on our tandem last summer for a 9-day trek on the C&O & Allegheny Passage trails. Stoker says two thumbs up! Not much of a nussiance at all and we came out nearly clean after 10 hours (over several days) of muddy trail riding. As soon as we saw what other riders looked like without fenders we immediately knew we made the right choice to put them on. If you are a day rider and can choose to not ride when wet, no need to put them on, but if it is likely you will be doing riding in the rain they are the way to go (especially for stoker comfort). We will never take them off, and I just put a set on my single road bike I was so happy with them. The Planet Bike ones were easy to install and very dependable. If they get out of line, easy to just push back straight with your hands. Do it! Heck with what it looks like, they add so much comfort if it is wet, and they keep the occasional gum wad from slinging on to your shins too. I think they actually look good too, but that is probably just me!