I have a ~2 mile/~20min cycle to work and currently take a rucksack with me that generally only contains my food for the day in a standard take-away container measuring about 17cm x 12cm x 4cm give or take.
I end up with a sweaty back in the morning which is a little annoying; so I'm wondering if there are any good saddle bags or similar that I could fit my food container, wallet and phone in (so something with a depth of maybe 10cm) to relieve the issue of sweaty back. Does anyone have any good recommendations because at the moment my rucksack seems a little like overkill.