A lot of front fenders have disappointing coverage. Some folks will use another rear fender in front, modified as necessary for mounting, to get better coverage.

Here's the current mud flap extension on my Serfas front fender. Just cable ties through holes to attach it. It could be longer still, but I had this piece leftover from another bike, and it is much better than nothing.


I initially tried making these mud flaps out of an automotive inner tube, but they were too flappy, and could sometimes get sucked into the fender if the wind was blowing the wrong way. 1/16" sheet is just right.