I'm actually in the process of removing full coverage fenders from my hybrid because there is the real risk of sticks or stones making the fender collapse into the wheel and lock it.
If you think about snow and mud, the full fenders are too close to the tire and will just lock the wheel when they are full of snow and mud.
The only time the fenders ever were useful is when after a rain. during rain I doubt they make a difference. for my commute I shower and change at work anyway. for fatbiking I don't care if i get dirty, no full fender keeps me clean anyway.
Just something to consider. i started out with wanting full fenders on both my bikes, just to realize they are not wort the effort and have an inherent risk. Added cost and weight as well.
If you go with fenders, the clearance to tire should be at least 20 mm and they should have breakaways. It also is recommended to have them closer to tire at the end (where the tire rotates into under the fender) and opening up to the front to reduce risk of things getting stuck. With knobby tires the risk of the tire bringing debris into the fender is bigger than let's say road tires. I researched all last night on that and saw horrific pictures of locked front wheels inc. broken off forks. I know that may only be a tiny risk overall, but it is there.
I know fenders are a polarizing topic and there are pros and cons. I'm not saying to do or don't, just something to consider. IMHO fenders have a place for commuters on paved roads. I just assume your case of a fatbike is not a paved road necessarily?
Just look at any MTB videos or dirty Kanza etc and see how many (or few) actually have fenders.
just my 2ct
Last edited by HerrKaLeun; 08-08-18 at 10:16 AM.