Ok, after having my micro wallet design with coin storage and clip for paper money, it turned out that I need even less for everday's commute , what is really needed for my commuter life (with bicycle), is to have the key for the lock of my bicycle, my door key as also company access card, an ID and the ATM card .
Nothing more needed. (as money is accessed via ATM and nearly everything can be paid by phone or ATM card).
So, I have reduced my "swiss army wallet" to the minimum.
Here it is the "nano wallet" - smaller, lighter and great for every day commute, without forgetting most important things: Keys,money(ATM) and ID.
Summarizing: you have space for 3 cards and keys.
**Update04.2019: so now I use it since Jan.2018, design turns out to be very durable as until now my original wallet (printed Dec.2017) is still in use nearly everyday...