spec me a... backpack to use for work commute

[Mucky_Pup]

I have a Hein Gericke rack bag for my chain and disc lock, and have a Hein Gericke rucksack (http://www.hein-gericke.co.uk/shop/product_info.php/cPath/23_150_147/products_id/8436) to carry all my other stuff, like clothes, and wallet, phone etc. It's too small for a helmet, I just carry mine.