Have spent 2 weeks looking for the perfect minimalist, small saddle bag that will hold an iphone, credit card and a $20 bill. It doesn't exist. I thought this would be perfect but it's 1 cm+ too small to hold an iphone 6.
https://us.sciconbags.com/elan-carbonium-series
I don't want to carry a spare tube or tools or anything else. The obvious answer is to just wear a jersey with pockets in the back. Instead I thought of an aluminum hardcase that would clamp to the seat post. Some kind of memory foam inside to store the minimum (phone, key, credit card, money) and protect the phone from vibration. Different sizes for different phones.
It would be lightweight, aerodynamic and stylish with different anodizing colors.
Stupid idea or something that people might buy?