Cannondale Topstone Carbon (Gen 2) Frame Storage

This project is a custom TPU storage compartment designed to fit perfectly inside the frame of the Cannondale Topstone Carbon (2nd generation) models without SmartSense.

Instead of leaving the frame cavity empty, this insert makes use of the space to carry essentials such as:

• a CO₂ cartridge,
• a TPU inner tube,
• and a few other small tools or items.

It’s a much more practical and clean solution compared to the unused hollow frame space.

Additionally, I’ve included a design for thumbscrews, printed in PETG for rigidity. They are completed with standard M4x20 countersunk hex screws. Since the screws sit a bit loose in the thumbscrew bodies, I recommend securing them with a drop of super glue.

The advantage of this setup is that the storage can be accessed without the need for a hex key – the thumbscrews can be turned by hand, making the compartment quick and convenient to open on the go.

Printed in TPU (insert) and PETG (thumbscrews), this solution provides flexibility, strength, and easy access inside the frame.