Introduction: Bike Fenders From Recycled Bike Tires

Picture of Bike Fenders From Recycled Bike Tires

If you hate to throw stuff away, then you will loves this Instructable. As a pack rat, you must have a number of worn out bike tires with no way to use them and no way to get rid of them. The answer is to use them as fenders on your road or other narrow tired bike. Besides the tire all you will need are some zip-ties (or wire or string), some steel rod or tubing, and some ingenuity. The result will keep your face and blaster dry while splashing through puddles on your bike. Read on!

Step 1: Materials

Picture of Materials

You don't need many materials for this project. The basic materials are an old bike tire, preferrably a wider mountain bike tire with wire bead, some steel rod or tubing (copper or other metal OK as well), and a refusal to throw anything away and pay $15 for a set of Chinese made fenders.


Bicycle that you want to put fenders on
One worn out wire bead bike tire wider than those on your bike
Some steel (or other metal) rod or tubing
A welder or torch to solder with
Some zip ties
Some scrap steel or copper sheet (20 Ga or so)
A power drill
A metal file
Some spray paint
A method to cut your tire
Misc bolts and nuts to mount your fenders.

To start with, take your scrap tire and cut it into sections that cover the desired portions of your bike wheels. See below for an idea of how much coverage is needed to keep you dry.

Step 2: Front Tire: Step 1

Picture of Front Tire: Step 1

From the pictures on the intro and this step you can get an idea of the scope of the project. You need to create some supports for the bike tire fender from metal rod or tubing that you can bolt to the various mounts on your bike. The wire bead in the bike tire will support itself over the rest of the span. Pictured below is the long arch that keeps the lower portion of the front fender from hitting the tire and the smaller saddle shaped piece bolts to the front brake caliper hole at the bottom of the head tube. Your bike may differ slightly but the general idea is the same: mount the fender to keep you dry.

To make the parts shown below you will need some metal rod and some scrap metal. First cut some tabs for bolting the large U-shaped part to the bottom holes on the front fork dropouts. Use a tin snips, and then drill holes in the tabs as needed. See pic.

When you have two tabs ready, bend a metal rod into a long U so that it will extend from your fork dropouts around your tire roughly parallel to the ground and will clear the tire easily. Trim the length of the U-rod so that it will fit correctly when installed. Then weld or solder on the tabs as pictured.

Once it is cool, test fit the loop by bolting it to the fork as pictured.

Step 3: Front Tire: Step 2

Picture of Front Tire: Step 2

With the lower U loop finished, the next step is to make the upper mount that bolts to the caliper bolt at the top center of the fork. Take a short section of metal rod and bend it into an arch that matches the curve of the tire you are using for a fender and that will easily clear the tire on your bike. Then cut a tab that will hold this arch at the desired height above your tire when bolted to the caliper hole in the fork. You will have to measure your own bike and adjust as you see fit. The pic below shows the idea.

With the tab welded to the arch, double check your measurement and then drill a hole for mounting the arch. You will need to cut a slit in your fender-tire to push the tab through and then you can test fit the arch to make sure that everything fits right.

Step 4: Front Tire: Finish and Mount It

Picture of Front Tire: Finish and Mount It

With both parts welded and test fit, the next step is to paint the metal so it won't rust. If you used copper this may not be needed. Once the paint is dry, you can mount the fender to your bike. The top arch and tab are bolted to the top of the fork at the brake caliper mounting hole. Nothing more is needed at the top. Make sure that the fender-tire does not interfere with brake operation. With caliper brakes you will most likely have to trim the fender so it remains behind the brakes. Cantilever and V type brakes have enough clearance so the fender-tire can extend through the brakes if desired.

At the bottom U loop, poke some holes in the fender tire where the loop crosses the bead so that you can push some wire or string or zip ties through the hole and attach the tire to the U loop. See attached pics.

Step 5: Rear Tire: Step 1

Picture of Rear Tire: Step 1

The fender for the rear tire can be very straightforward if you have a cargo rack. In my case I had a cargo rack that I built out of old steel brake line. If you have a steel rack, welding on additional hardware for the fender is simple. If you have an aluminum rack it can still be done but requires more specialized equipment (TIG). If you don't have a rack at all, you can make a U loop similar to the one used on the front tire and complete the rear fender without much trouble. Here I present my method which involved adding a rear arch to the back of my steel cargo rack, and using zip ties to attach the topof the fender-tire.

For the top of the rear fender, use a knife to cut a small slit in the fender-tire near the bead and at the point where the fender-tire crosses the rear seat-stay tubes. See the attached pics. Then the fender is held in place by threading zipties through the slits and tightening them around the seat stays. Easy as that.

Step 6: Rear Tire: Wrap Up

Picture of Rear Tire: Wrap Up

The back of the rear fender is held off the wheel by an arch welded between the rear supports of my steel cargo rack. This is simply another section of scrap steel tube bent to shape, with the ends pounded flat with a hammer, the paint wire-brushed off of the rack, and the arch welded in place. The rear fender just rests in place. In practice this works well.

Hopefully all this has made sense. Since each bike is a bit different and anyone considering this project probably has a well customized bike I hope the preceding serves as enough of a framework to allow others to adapt to their specific needs. Happy making! Feel free to contact me for clarification or questions.


crlsbrrds (author)2012-12-16

Hi there!
I used my old/dry thin tires...
1 tire; 2 aluminium bars 10x2mm; 4 bolts 3mm. 12 alu revits.
This is the result...

crlsbrrds (author)crlsbrrds2012-12-16

The pic's...

razorwinged (author)2012-12-02

nice one!

starplayer (author)2011-04-04

The zip tie itself is held in place only by friction? Won't it fall down with vibration?

jmengel (author)starplayer2011-04-04

The zip tie is held in place by friction. Pulled tight, the zip ties presses the bead of the tire against the seat stay. If the zip tie is not tight enough, it can slide down over time and the tire fender will start to rub on the tire. If in doubt, pull tighter.

criggie (author)jmengel2012-03-19

I did that a couple weeks ago.. the lightweight cable tie broke and I punched myself in the face.

Not the best outcome.

azimmerman2 (author)2012-03-15

Thanks, after two weeks of debatin on whether or not to buy fenders I turned to Instructables to help, I had these on within 40 minuites of finding them (including dinner).

jmengel (author)azimmerman22012-03-16

Great! Hope they keep you on the road in all weather.

oazhar (author)2011-09-30

haha...very good idea!

frogmeetcog (author)2011-07-25

The ends of the steel rods can also be pounded very flat and wide, then drilled (my preferred method, especially when using the wires left over from campaign signs) or bent into an eyelet with sturdy pliers. Either solution eliminates soldering.

jmengel (author)frogmeetcog2011-07-26

Hey, good idea. I guess when you have a welder, everything looks like it is ready to be welded. Thanks for sharing.

bikebum1975 (author)2011-05-06

Excellent idea I just happen to have a pair of old mountain bike tires I could mod for this. Cheers

orisj (author)2011-04-12

Cool! Indeed a great idea!

BtheBike (author)2010-10-07

this is a great idea for refurbing those old bent and rusted metal fenders .

f3rg (author)2010-09-18

If you run 25c tires, I could see this being done very stealthily using 38c tires w/ wire beads. Very cool.

JerryMopar (author)2009-11-08

what an excellent idea!!! I really do like it. SImple, cheap, uses what would be normally junk, perfect!

Yerboogieman (author)2009-07-17

I would be honored if you would join my group "Featured".

jmengel (author)Yerboogieman2009-07-19

Will do.

green67 (author)2009-03-06

BRILLIANT!!..I' want more than the "mudflap" I have.

rimar2000 (author)2008-11-10

Excellent idea, congratulations. The earth needs more people as you!! This things seems simples, but they have a great environmentally friendly charge.

killerjackalope (author)2008-11-09

Hmm this could be what I'm looking for, I want fenders on my bike but I need something that'll fit in well with it and be fairly rugged, I tend to make sure all my bikes get used to their potential, then see how much further they go...

jmengel (author)killerjackalope2008-11-09

Well in that case you may want to try better mounting methods at a couple of points. I have found that the zip ties and wires do tend to break under hard use. Not often, but if you crash or if you have to cram the bike into a full public rack you may find one of the wire/zipties have sprung. The good news is they are easily repaired. I have had to scrounge around for wire or twist-ties in parking lots to reattach.

killerjackalope (author)jmengel2008-11-09

I have the distinct advantage of having trousers sewn together with wire, I just wiggle a bit to break off when needed, usually because I ripped them somehow, one pair are nearing and equal weight of copper and denim... On the other hand I'd probably use stubby bolts and put them through the tyres as fenders, simply to make it both sturdier and less effort to take off for whatever reason, they'll look similar but be quite differently built I'd say...

Chicken2209 (author)2008-11-09

Good Idea I always hate it when I scape up my backpack

RemBrandNL (author)2008-11-09

Excellent idea!! Great c2c spinoff. I just love these simple idea's that reuse materials without further processing.

Ezza (author)2008-11-09

Fantastic idea! "Why didn't I think of that?". I'll make some of these when I wear out a tyre.

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