Bicycle fenders protect you from back splash as your bike tires roll through mud and puddles. Some bike finders have more than a functional use, however: they can be painted to accentuate the style of your bike, or be decorated with decals or even glow-in-the dark tape. You’ll have to check the size of your tire–listed on the tire wall–to buy the right size fender. Most bike tires, for example, are 26 inch or 700 cubic centimeters, and take the same size fender. Fortunately, installing fenders is a simple process that takes less than an hour to complete.
Put together the braces and the fenders. The braces look like long metal "V"s and attach the fender to the bicycle frame. Align the mounting holes at the apex of the brace to two of the mounting holes on the fender and secure together with two small nuts and screws. Repeat this process for another brace at the opposite end of the fender, as well as for the second fender.
Take the front wheel off of your bike. Slide one fender through the fork and insert a bolt and washer through bracket at the apex of the fender and then through the threaded hole at the base of the fork. Tighten the bolt with a nut and wrench.
Reattach your front wheel to the fork and slip the mounting hooks at the ends of the braces around the axle of the wheel. Be sure that these hooks rest outside of the fork. Tighten the hooks to the axle with a nut on each side of the wheel. Lift your bike off the ground so the front wheel can spin freely and check whether the wheel rubs against the fender. If it does, adjust the fender by pulling on the braces to move the fender out of the path of the spinning wheel.
Take off your rear wheel, loosening the chain around the hub and turning the bike upside down. Balance the bike on the seat and the handle bars. Have a friend hold the bike steady if need be.
Insert the fender so that the inside surfaces faces upward to you and align the small mounting hole of the fender with the hole on the frame. Insert a screw through these two holes and tighten securely.
Reattach the wheel and the chain and secure the rear fender brace hooks around the axle just as you did with the front fender. Check that the rear wheel spins freely while the bike is still upside down by turning a pedal with your hand. If the tire rubs the rear fender, adjust the braces with your hands.