Backpack Pannier for Bicycle

I have been trying to make my own pannier for some time now but wanted to avoid modifying my backpack and especially sewing.
This instructable is what i came up with based on ideas I found elsewhere and here:
Backpack-panniers-that-are-still-backpacks

Parts :
- Backpack
- Over Door Hanger
- Bungee Chord  (approx 18" or 45cm)

Tools :
- Dremel Tool or Saw

Discalimer :
I am not responsible for any injury or loss incurred during the making or use of this Instructable.
Make and use at your own risk!

Step 1: Cut Over Door Hanger

The over door hanger used was plastic coated steel wire hanger purchased form a Dollar store.

+ Leave at least two hooks at either side of section to be cut
(Having more than two hooks might be useful as backup but if your bicycle rack is not perfectly straight then the bag might have a tendency to rock slightly.)

+ Using Dremel tool or saw cut the over door hanger to the width of backpack
(Make sure to follow safety procedures while using cutting tool)

+ Clean rough edges of cut by sanding or otherwise

Step 2: Shorten Straps

+ Shorten the backpack straps as much as possible.

+ Ensure that the extended straps are folded or tied so that they do not get entangled with the spokes of bicycle wheel 

Step 3: Pass Straps Over Front of Backpack

+ Flip back pack straps over the front of backpack

+ Pass the cut hanger section underneath backpack straps

Step 4: Hook Bungee Cord

+ Hook bungee cord on one side of hanger section

+ Pass bungee chords around backpack straps

+ Hook bungee chord on to other side of hanger section

Step 5: Place on Rack

+ Hook hanger section on to bicycle rack

+ Loop bungee chord around bottom of bicycle rack

And you are done!