The wire 2mm I used was only just strong enough for this so I'd use 2.5mm or even 3mm wire if I made these again. The front guard is perfect but the back one rattles a little.
I've entered this into the inner tube reuse contest so don't forget to have a look at all of the entries and vote for your favourite ones, when the time comes.
Here's what you'll need :
- Steel wire 2.5mm - 3mm (if using 3mm wire, a small amount 2mm wire will be better for the cross pieces)
- Scrap steel sheet about 1mm thick
- Old inner tube (thick MTB tube is best)
- Washers to suite the bolts
- Leather punch
- Eyelet tool
- Allen keys to suit bike
Step 1: Cut Your Inner Tube to Size.
We'll just work on the front mudguard first. Measure the distance between fork eyelets and the edge of the mudguard. Add this to the length of the piece of inner tube you cut. Double this and add a foot spare for mistakes/clearances etc.
Cut a piece of the steel wire to this length and bend a U shape in the centre about the same width as your inner tube. This will be the beginning of the skeleton of the mudguard.
Step 2: The Front Metal Bracket
Before you cut it out, drill all the holes, the hole sizes will depend on the mounting bolt and the size of the eyelets/rivets that you're using. You can clean the edges of the holes using a Dremel or a file.
Cut the shape out and fold the tabs over the wire U shape. Hammer them flat, to secure the wire. Next, drill all the way through the eyelet holes and crimp the eyelets in place, to help secure the metal tabs closed.
Step 3: Slots for the Cross Pieces
To keep the mudguards flat profile, there are cross pieces separating the two steel wires. The rest in V slots so that they can't slide along the wire. The first V slot was a big one, not for a cross piece, but to keep the sheet metal piece in place should it ever come loose. The rest of the V slots were made at 10cm intervals from the sheet metal up until the shoe mark.
Step 4: Adding the Cross Pieces
When you've made these you can wrap as tight as you can between each of the V slots.
After they're all in place, mix up some epoxy and apply it to the where the cross pieces are wrapped over the V slots. This stops them moving along the wires and stops any rattling.
Step 5: The Mudflap and Eyelets.
About an inch away from this, mark a line right across the tube. Cut down the sides of the tube up until this line, and cut across the line, this will remove one half of the tube around the mud flap. This is so you can get the tools in for the eyelets.
Punch two holes using a leather through punch or similar through one side of the tube. You can install the eyelet now. It's quite awkward to get the eyelet tool in place, but possible!
Step 6: Slide the Inner Tube Over the Skeleton
Once the inner tube is fitted all the way along, you can bend the wire to a right angle where it leaves the eyelets. This is to point the wire toward the the forks.
Step 7: Fit the Guard
You should have a washers to spread the load a little, I didn't have an suitable washers in my junk box, but I'll be buying some ASAP.
That's the front mudguard done! The first time you ride it might rub a little, just keep making adjustments until it's silent!
Step 8: The Rear Guard
Because there's absolutely no clearance under the brakes on my bike, I had to go over them. The sheet metal bracket it made in the same way as the front except that it has a long strip attachment, so that it can bend over the brakes and to the brake bolt.
Step 9: The Skeleton (2)
Step 10: Inner Tube Eyelets
Step 11: Attaching the Mudguard.
Step 12: Extra Support
Add washers and tighten everything up. It's finished now!