Bike fenders from water bottles and clothes hangers

Picture of 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.
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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:

- 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.

- 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
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
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.
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:
rowerwet5 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 :)