If the mud flap on the front fender is 1" from the ground, its perfect. The length of the rear fender should depend upon how polite you are to other riders, the longer, the more polite you are.

But riding without fenders in the rain is pretty disgusting. It will ruin good shoes and throw oily, dirty water onto you. Light rain can actually be pretty nice on a summer day but oily water from the road is gross.