Patchwork Rucksack

I had been wanting to make a rucksack for daily use to work, I found this pattern and really liked it. I had some Lecien fabrics that would work wonderfully.  To make the bag a little waterproof I put in an extra layer of shower curtain between the top fabric and the batting. It makes a bit of a  crinkly noise but has worked well.

 I am not sure if it is how I have placed the handles or the design of the bag, but the balance isn't quite right, it always wants to topple forward when held by the handles