HEMA Achterlicht Bracket

HEMA Achterlicht Bracket (Images are upside down compared to how it's installed on the bike)

A simple, sturdy and parametric L-shaped bracket for mounting a HEMA rear bicycle light (achterlicht) to a bicycle luggage rack/bagagedrager.

I needed a way to mount my HEMA rear light to the luggage rack while still using the light's original two mounting bolts. The bracket attaches to the luggage rack using standard zip ties (tie-wraps), so no modifications to the rack are required.

Dimensions

The default configuration is designed for:

• 2 mounting bolts

• 5 mm bolts

• 75 mm center-to-center bolt spacing

• Zip-tie or Velcro attachment to the luggage rack

The mounting holes have a little extra clearance to make installation easier.

Parametric OpenSCAD design

The model was made in OpenSCAD and is parametric. If your HEMA light or mounting setup is slightly different, you can adjust the parameters in the OpenSCAD Customizer.

Adjustable parameters include:

• Light mounting hole diameter

• Distance between the two mounting holes

• Bracket width

• Light plate height

• Rack plate length

• Material thickness

• Zip-tie slot dimensions and positions

• Reinforcement/gusset dimensions

The triangular gussets are positioned at the outer edges of the bracket. This reinforces the 90° joint while keeping the area around the light mounting holes clear.

Printing

For bicycle use I recommend PETG, ASA or another material suitable for outdoor use.

The bracket is exposed to vibration, sunlight, rain and temperature changes, so PLA may not be the best choice for long-term outdoor use.

After printing, attach the HEMA rear light using its two original bolts and secure the horizontal part of the bracket to the luggage rack with zip ties.

AI assistance

The design requirements, measurements and intended mounting method are my own. AI was used to assist with creating and refining the parametric OpenSCAD code.