First! DO NOT RIDE ON MUDDY TRAILS! But if you're heading out onto ATV tracks or a deliberately-muddy cyclocross track, we have some advice for you. Here's a quick way to keep the cable damage to a minimum.For each place where a cable enters a housing, tear off a 4-inch strip and a 1-inch strip of duct tape.
After the mud and water exposure, remove the tape. Use adhesive remover (or nail polish remover) to get any stick-um off the cable and frame.
Let's cover it up.
Once you're through with that cold, muddy ride, pinch the duct tape down to make sure it's securely in place. Then wash the bike down fully. After hosing, peel the duct tape away.
If you get adhesive buildup on the cable, clean it off with acetone or nail polish remover. Paint thinner can work, but not as well.
Other winter-proofing items, with my humble experience:
Detachable rear "mud fender": Worthwhile. The most convenient are those that clamp quickly to the seatpost. Keeps the water from spraying up your butt and back.
Detachable front "mud fender": No. Somewhere, there must be one that will work. I tried three brands. But none survived more than a single ride. First fall = break fender. In fact, I broke one in my garage when my thigh bumped the front wheel as I walked past.
Derailleur protector: No. Must be a roadie thing. Forget it. A pain to put on. And, it will quickly fill up with mud. Worse than worthless if you ride in real mud.
Shock covers: Not impressed. The muddy water quickly gets inside, where the sand and grit is caught by the sleeve and held against your stanchion. Even if you remove it and clean it after every ride, your shock will wear out faster with a cover than if you do nothing.
Shoe covers: Sure. Why not?