This is a quick hack I just thought of to make a rear mudguard for the rainy season. It should be noted that this setup may be only suitable for those with a unused rear brake bridge like those cycling fixed gear bikes or those with disc brakes. The reason for this is that the guard is mounted on the rear break bridge. Some fixed gear cyclists remove the back brake as back peddling and locking the back wheel is adequate to stop the bike and some disc brake fitted frames have a drilled rear brake bridge.
The mudguard is manufactured from household tools and spare parts lying around and takes about 30 minutes to make and fit. The main structure is from an old scrap aluminum bike wheel. Since this is essentially a bike part it somehow looks okay and works well as a mudguard.
Step 1: Get Your Kit Together
To make the guard you will need the following:
1. A glue gun and a glue stick.
2. A hacksaw.
3. A scrap bike wheel (I used a battered aluminum wheel, measuring 622x17x6106, The larger the diameter of the wheel the better as you want it to curve around your wheel. Adjust the size of your jubilee clip accordingly.)
4. A jubilee clip (i used a 12-20mm clip but the size of the girth of your scrap wheel will dictate which size you should use.You want the clip to be a tight fit.)
5. A metal file.
6. A spoke and nipple.
7. A piece of string around 330mm long.
8. A M6 bolt 40-50mm long.
9. 6 x M6 nuts.
10. A bendable sheet of tough plastic roughly 300mm by 40mm. (I had a small sheet of transparent thick vinyl lying round but you could easily use thick plastic from a bottle or other container)
Step 2: Cut Your Wheel Up
Using the 330mm long bit of string arc out a measurement on your scrap wheel. This will be the length of the mudguard structure. You can change this length as you like but this is the minimum stretch I required using my materials and this initial design.
Using the Hacksaw cut through the wheel and remove your section. Unscrewing the nipples from the spokes. Save a nipple and a spoke for later. File down the ends so that they are square and clean. This will allow it to sit cleanly against the bridge.
Step 3: Assemble Bolt and Nuts
Put the 6 nuts on the M6 bolt making sure the nuts rest against each other but not too tightly as you want to be able to unscrew the bolt easily later on. Next check that the clearance of the bolt head and the nuts is the same width of your brake bridge. If you have excess bolt at the end, you will need to cut this off by holding the bolt in a vice or some other method.
Step 4: Fix the Bolt to the Inner Rim
Using your glue gun glue the bolt to the inner rim of the mudguard section, allow the first bolt to be flush with the edge of the wheel section. Pump plenty of glue in there so that the nuts are completely submerged and the glue fills the cavity under the rim.
Wait a couple of minutes until the glue is dry then remove any excess with a file or sharp knife and fit on the jubilee clip and tighten.
This setup should be strong enough to support the structure. However you could probably think up stronger and less clunky designs using better materials.
Step 5: Fit the Plastic Extender
Using the piece of plastic which is cut about 300mm long and slightly wider than the width of the wheel, slot it into the other end rim of the mudguard. This extension allows you a lightweight means of extending the reach of the mudguard.
Step 6: Mount the Mudguard on the Brake Bridge.
Unscrew the bolt and mount onto your rear brake bridge. If the mudguard sits well and doesn't touch the wheel, well done. If it is touching the wheel you may want to add structural support and lift by using the spare spoke and nipple. You can thread the spoke through one of the holes and attach to the seat post or frame. I wrapped mine around the seatpost bolt, which works fine for now.
The beauty of this hack is that it is easy to fit and remove, is worthless to thieves and is recycling busted wheels. Any improvements suggestions on materials and design are welcome.