Before I set out on my first self contained tour I must have read 8-10 blogs and multiple lists for suggested gear and general bike and riding suggestions.

One thing I never saw was a reminder to check fender clearance.

I'm riding on a trail that was crushed stone but with large intermittent segments of packed dirt. Unfortunately, frequent rain turned those packed dirt segments into a muddy quagmire. Because I had very minimal clearance between my tires and fenders, the mud essentially clogged everything up and it was like riding with my brakes engaged. My back wheel literally came close to seizing up and I needed a screw driver (sticks were breaking) to pry the caked mud out of the fender. It was like concrete.

The mud even seeped down the sidewalls of my tires and fouled my brakes.

Every time I cleared the mud out, it came back within a 1/2 mile or so. I thought that I was sick and without energy but I eventually saw that most of my problems were fender/tire related.

Lesson learned.

Fenders and mud roads, I mean dirt roads after rain, don't play well together, IME. No matter how much clearance you have, mud can build up to where it interferes with the fenders; it just takes the right combination of dirt and water.

First time I ran into this phenomenon it was kind of funny listening to the wheels. It sounded like the wheel was coughing up a wad of phlegm and then spitting it out, over and over again. Then the wheel jammed.

Sounds like the first time I tried riding my bike in the snow as a kid. Didn't get far. My bike tire quite literally "snowballed."

I've seen photo's of that on others bike and it can be quite the holy mess! But they still recommended using fenders because it was so infrequently that it happened. Guess it depends on where you do most of your biking.