I needed an inexpensive pannier for bike commuting to work. The pannier would hold some basic tools to fix a flat and perform other minor bike repairs on the road. It will also hold a change of clothes and lunch. In past, I had ordered a pannier set form an online bike accessory and bike dealer but the pannier tended to fall off the bike due to very flimsy tension cords so I returned them. Also, it had a draw string closure on the top which was ugly.

So, I had to make my own panniers as it hard to understand why a decent backpack would cost $20 but a decent pannier would cost 3x that much. This instructable shows a very serviceable pannier made from upcycled school backpack and hooks recycled from an IKEA over the door hanger. The IKEA product is no longer available but any suitably sized J hooks could be used. There are other articles on making panniers from buckets, etc. and the same general technique is applied here.

Step 1: Materials

You will need to source the below materials.

What is needed is

- A suitable backpack, school backpack is more suitable than a laptop backpack for general use but you may want a laptop backpack if you want to carry a laptop. A backpack with a handle on the top is ideal. The handle is used to pull the backpack on to the rack after first attaching the bottom hook.

- Coropac sheets from salvaged lawn signs to be used as stiffeners for the backpack back panel. This is needed so that the back panel will not get caught in the wheel.

- 6mm nuts and bolts to bolt the hooks to the backpack. This could be smaller diameter, too depending on the hook dimensions. I was using flat and wide hooks. You may need 25-30mm or longer bolts depending on the thickness of the hook and coropac panel.

- Washers

- S hook or wire bent to form a loop and hook for the bottom of the tension cord

- A bungee cord or a spring or a piece of rubber from an old inner tube

Step 2: Measure and Make Holes

First of all you will need to remove the shoulder straps from the backpack. These are best removed by cutting off as close to the back pack as possible while leaving the seams intact. You may seal the cut edge with a small flame from a candle or gas lighter. This will prevent the fabric from fraying.

Save the straps as you will need to sew a length of it to the backpack to hold the tension cord in place at the bottom.

Put the hooks on the back rack. Hold the backpack where you want it on the back rack and measure the position of holes for the hook. This will depend on your bike and rack. You need to insure that the front edge of the backpack clears your heel when the pedal is horizontal and towards the rear wheel on each side.

Measure the location of the strap to be sewn to the back panel of the backpack. This will depend on the location where the bungee cord will attach to the bike via the S hook.

It may be beneficial to make a cardboard or coropac template shaped like the back of the backpack to make the holes and make sure that everything aligns well before actually making the holes.

Step 3: Assemble

Attach the hooks on the outside with the coropac stiffener inside the backpack using nuts, bolts and washers, as shown in photo here.

Attach the bungee cord ends to the backpack at suitable points. In my case I had to drill extra holes in the hooks and attached the hooks there.

Pass the bottom end of the bungee cord loop through the strap loop and attach the S hook. In my case the hook was bent from an aluminum wire I had around. Probably ground wire from a Romex cable. See photo.

Step 4: Attach and Ride

Here is a view of the backpack attached to the rear rack of the bike.

The strong bungee cord keeps it firmly on the bike even on bumpy rides. You can see why the off center location of the loop was necessary to keep the backpack from touching the heel.