Cube Longtail Backrest

Backrest mount compatible with the Cube Longtail cargo bike

The mount was designed with a focus on stability and durability and features a reinforced clamping construction around the frame tubes.
The parts shown were printed from PETG-CF with a very high wall count to achieve maximum stable structure.

For this project, a universal back cushion from AliExpress was used. Similar cushions with comparable dimensions should also be compatible.

Assembly overview

1. Hold the printed mount to the back of the back cushion and mark the drill holes
2. Carefully drill the marked holes (do not drill too deep)
3. Open the zipper of the back cushion
4. Carefully detach the cushion from the inner back plate (if necessary)
5. Insert screws from the inside through the opened zipper
6. Attach the mount and screw it from the outside with the nuts
7. A wrench can be used from the inside through the opened zipper to hold against it
8. Attach the complete backrest to the bicycle frame with the printed clamping holders

Required hardware

Back cushion:

Back cushion assembly:

• 4x M6x25 hex head screws
• 4x M6 self-locking nuts

Frame holder assembly:

• 8x 4x30 mm screws with coarse thread

Optional:

• thin TPU/rubber strips for additional grip and paint protection

Recommended print settings

Material:

• PETG-CF recommended
• alternatively ASA or PA6-CF

Used settings:

• 0.24 mm layer height
• 20 wall lines
• low infill
• No support required

The design deliberately focuses on high wall thickness instead of extremely high infill to achieve maximum stability in the stressed areas.