I asked a few riders who do much more single track, mud etc than I do...they all said pretty much the same thing...Fenders when traveling on rough terrain can become a problem because mud, snow etc...can get caught up underneath and jam things up them and one rider even said he heard of a case where so much mud built up underneath it caused the fender stay to fail and the fender went into the front wheel, which caused the rider to pull a header. A couple of dudes I know are are more "hard core" riders than me and they both like the back rack with a "grunge board" to stop mud. I think its the best way to go for a cross country type rider. Probably the safest way.