The ORTLIEB Toptube Frame-Pack is the smart solution for all who want to use their frame’s main triangle for storage space without having to do without their water bottle. The solution also works for those who have full-suspension mountain bikes with limited triangle space. The Toptube Frame-Pack provides plenty of space for heavy equipment such as tent poles, tools and food supplies, while also helping to secure a low center for improved rising performance. And given that the bag and its Tizip zipper are waterproof, you can even cross rivers on your bikepacking tour without worrying about your stuff getting wet.
The Frame-Pack attaches easily to your top tube and seat tube with the help of sturdy and highly adhesive Velcro straps.

Further features:

+ Ideal for all bikes with limited triangle space
+ Reflecting logo

Advice:

Suitable for carbon fibre frame.
You can download a template to proof the size according to your bike:
Here template Framepack Toptube 3L

Here template Framepack Toptube 4L
(download PDF - print on paper (no scaling) and glue parts together)