One of my first projects. Now my spare tube has it's own bag and will be protected from the sharp thingies in my bike bag. It also fits nicely in jersey pocket.
Joey Downtube Bag - Cargo | Revelate Designs LLC
Underdog Downtube Bag – Troutmoose
Strive CFR Underdog | CANYON US
21 Bags ideas | bags, wald, saddle tooling
116 Best Bike Frame Bags for 2024 - Page 2 of 8 - The Cyclelist