Most people install a light onto the rear of the seatpost, with the light sticking out at the rear. This means that when lowering the seatpost, care must be taken not to lower it all the way down and damage the light clamp. Also, depending on the rear light design, it may or may not interfere with the seat post clamp.
Instead of doing that, I decided to mount a rear light onto the rear rack, using the mounting used for the rear reflector. Of course, this only works for Bromptons that have a rear rack.
Original rear reflector on the Brompton rear rack
It took me quite some time, trying out different brackets and mounting positions before I could find a suitable place to mount the rear light. The main challenge is to mount the rear light without it getting in the way during folding, while still pointing at the correct angle. At the same time, the rear light should be easily removable for charging. The rear light that I want to use is the Moon Comet rear light, which is a compact and bright rear light.
After much trial and error, I finally managed to use the Cateye mount (for saddle rails), and combine it with the Moon Comet rear light mount. The Cateye mount is clamped onto the two original L-shaped brackets used to mount the rear reflector.
L-shaped brackets + Cateye saddle rail mount + Moon Comet mount
Moon Comet rear light mounted at the rear of the rack
At the same time, note that I have managed to reinstall the bungee cords onto the rear rack! Previously they were removed as I could not hook the bungee cords onto the bolt of the rear Eazy wheels, like in the stock condition. However, I realised that since the bungee cords end in a loop, I can just put it through the rear rack as shown. Simple solution!
The light is protected by the Eazy wheels, and also does not protrude out from the rack, making it possible to fold the bicycle without hitting the rear light.
Good clearance with the ground, will not hit objects when rolling the folded bike
Rear light DIY installation completed!
Next, after installing the rear light, the front light also needs to be installed. The obvious solution is to install the front light on the front bracket, which comes stock with a front reflector.
Front bracket with original front reflector
Studying the position of the front bracket when folded, to see the clearance and space available for mounting a front light
Instead of making a complex bracket mounting due to lack of space, I decided to just bolt on a QR axle extender...
...and wrap the rubber strap of the Moon Comet front light onto it!
No interference with the frame or cables during folding
Compared to the rear DIY mounting, the front mounting is much easier and straightforward. I basically just placed some material on the front bracket for the rubber strap to wrap around.
With this, the DIY front and rear light mounts are completed! There are no protruding parts that will interfere or compromise the compact folding. These DIY mounts also allow me to use the existing spare lights that I have, instead of buying more lights.