Bike Fenders From Water Bottles and Clothes Hangers

This instructable will show you how to make fenders for your bike using plastic water bottles, clothes hangers (for structure), and twist ties.

I've seen stores sell mud shields for mountain bikes, but I've never seen any full fenders for sale, so I decided to make my own. Since I live near Portland, Oregon (which has a large and thriving bike community, but also lots of rainy weather) i hope that my new fenders will encourage me to ride more in the rain.

Step 1: Materials and Tools Needed

This project took me 4-5 hours. The materials and tools I used are:

Materials:
- 6 water bottles. I used 500ml. (2 to make the front fender, 4 to make the rear fender)
- 4 wire clothes hangers
- Several wire twist ties or zip ties.  (I used 6 paper-coated wire twist ties and 7 longer plastic-coated twist ties.

Tools:
- scissors
- needlenose pliers
- wire cutters
- one-hole punch
- ruler (optional)

Step 2: Cut Up Bottles and Unwind Hangers

First, use the scissors to cut up the water bottles. Cut off the top and bottom and you'll have a tube. Then, cut the tube in half. Look closely and you'll see a plastic seam running down each side of the tube. Cut along the seam so you have 2 equal halves.

Then use the pliers, or just your hands, to unbend the clothes hangers. Try and make the hangers as straight as possible.

Step 3: Punch Holes in the Tube Halves and Join With Wire

Now use the one-hole punch to punch a series of holes on each side of the plastic tubes. Punch the holes nearest the edges first to get the spacing right so they will overlap well. Then punch another hole about 4 cm away from the first.

Next, extract the piece of wire from the paper-coated twist tie (or just use any thin wire you have handy) and use it to join the 2 plastic sections together. Trim off any excess with the wire cutters.

Join 4 halves for the front fender and join the remaining 8 halves for the back fender.

Step 4: Thread the Hangers Through the Holes You Punched

Now using an under-over pattern, start threading the straightened hangers through the holes but skip any hole that joins two sections together because you want the pieces to be able to pivot and flex to take the curved shape of the wheel.

Step 5: Attach Front Fender to the Bike

My front fork had an eyelet hole open on each side near the axle, so I was able to use it as an attachment point for the fender.

Use the needlenose pliers to bend one end of the hanger into a tight loop and insert it into the eyelet. Then tighten with the pliers. Extend the hangers straight out, and about 1-1.5 inches past the tire, use the pliers to bend the hanger up almost 90 degrees. Repeat on the other side. Bend the rest of the fender frame by hand so that that the fender matches the curve of the wheel.

Next, trim the excess length of each hanger near the top of the wheel and use one of the pieces to make a spacer for the fender frame. Secure the spacer using more twist-tie wire. Finally, secure the top of the fender to some point near the split of the fork. I punched a couple more holes and used a twist tie to secure the fender to a reflector.

Step 6: Assemble Rear Fender and Attach to Bike

The rear fender is assembled in the same way as the front fender, but the attachment is a bit different.
Depending on your style of bike, you may have to get a little creative to find good way to attach the rear fender.

For the rear fender, join together the remaining 8 water bottle halves with wire.
Next, thread the 2 remaining hangers through the punched holes like before.
Before attaching the fender, bend it into a curved shape.

I decided on 3 attachment points and used plastic-coated twist ties to secure the fender to the bike frame (zip ties would also work well.)

Step 7: Final Thoughts

After both fenders are assembled and attached to the bike, take time to fine tune the curve of the hanger frame so that the tires don't rub on the fenders as you're riding.

To make them look a bit more stylish, you might want to spray paint the fenders before attaching them to your bike.

The fenders feel a little flimsy (especially the front one because it is only attached to the bike at 2 points), but they are made with everyday household items and cost me $0.00. I haven't ridden in the rain yet, but on a test ride, I don't hear any tire rubbing against the fenders, so I think I'll be OK.

Good luck, ride safely, and most of all have fun!!!