loading

Bike fenders from water bottles and clothes hangers

Picture of Bike fenders from water bottles and clothes hangers
P1010316.JPG
P1010315.JPG
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.
 
Remove these adsRemove these ads by Signing Up

Step 1: Materials and tools needed

Picture of 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

Picture of Cut up bottles and unwind hangers
P1010268.JPG
P1010266.JPG
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

Picture of Punch holes in the tube halves and join with wire
P1010277.JPG
P1010279.JPG
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

Picture of Thread the hangers through the holes you punched
P1010286.JPG
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

Picture of Assemble rear fender and attach to bike
P1010304.JPG
P1010305.JPG
P1010307.JPG
P1010312.JPG
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

Picture of Final Thoughts
P1010316.JPG
P1010315.JPG
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!!!
You could also heat up the plastic and warp it so that it's wider if it rubs on anything. I found it easier to use 12GA(sorry for you metric folks out there, I simply do not care about metric wire gauge) insulated solid-core copper wire than using coat hangers because copper is more machinable than brass
vegatek6 years ago
Good Instructable, easy to follow and full of details.. Recycled bottles look good. My only concern are the coat hangers. If they do not provide enough rigidity, the bottom end of the fender might catch onto the tire and as a result might be pulled all the way into the tight spot between the tire and frame/front fork. Please let us know how the testing goes - I hope everything will be OK
namatuzzi (author)  vegatek6 years ago
For a few test rides, different parts of the fenders were rubbing on the tires, but nothing ever got sucked into the wheels. The worst that I've seen is that the 2 arms of the front fender sort of bounce back and forth off the sidewalls of the front tire. I guess if you have very knobby tires, then there's a greater chance something could get sucked in, but I still think that's unlikely.
namatuzzi (author)  namatuzzi1 year ago
After about 2 months, the front fender did get sucked into the fork. There was just not enough support to keep the front fender isolated from the spinning tire. I removed it. The back fender is still going strong 4 years later.
skoster2 years ago
or cut up windshield washer fluid jugs.
skoster2 years ago
Good Instructable. Suggestion = use cut up gallon milk jugs for fenders like in this instructable: http://www.instructables.com/id/Bicycle-fender-made-from-a-plastic-jug/?ALLSTEPS
rowerwet6 years ago
I did something like this once for a bike only I used 2" wide strips of vinyl siding from scrap left over, this worked well as the vinyl tends to want to stay flat and not rub.
Seems you could glue or cement the pieces together with some fancy glue available nowadays once it is put together. It should make it more rigid as well as waterproof. Might even be able to then remove the hangers.
rimar20006 years ago
Very good idea. I think you can dispense the last tho bottle halves of the rear fender, without losing efficiency
namatuzzi (author)  rimar20006 years ago
I originally thought about leaving a few segments off the front and rear fenders, but I had already cut the bottles and I had extra room on the clother-hanger frames, so I decided to opt for more coverage rather than less.
HAHAHAHA!!! That isn't a good reason for do it. It is not even a reason. But (and you do not tell anyone, it's a secret) I very often fall into the same trap.
Very economical idea, fenders are SO expensive. Re PKM's suggestion for a less angled look - maybe use 2 liter soda bottles instead of the ribbed 500mL mineral water ones? Since they're bigger, they could probably be cut into thirds instead of halves lengthwise.
PKM6 years ago
For a slightly less "industrial" angly look and a more uniform curve, could you soften the bottle halves with a hairdryer and slightly bend them for one smooth arc? I rody my GT to work in the snow today, bike and self were covered in horrible brown road slush after ten minutes. If this weather continues I think I will make a set. Anything that makes the bike look less attractive for stealing will also be a plus :)