El-Cheapo Motorcycle Mirrors

TL;DR mirrors are required by law for a reason
EDIT : I actually already covered the subject last year... but I will keep both posts.

Driving like Noddy in his little yellow car is certainly part of the appeal of owning such a toy. It didn't take us long to try this on the beach in winter last year. It was cold AF, and we certainly learned that driving without side screens is not very enjoyable because of the massive air turbulence. At any speed over 70 kph, the experience is close to what I imagine breathing with a CPAP must feel like. Some fear they'll lose their sunglasses; I wasn't convinced my beanie was really safe either. You certainly need earplugs.

On top of the battering, the lack of side mirrors wasn't optimal. It was barely OK on empty country roads, but they are really missing when driving around town during rush hour.

Looking for small "F1" style mirrors similar to the ones I had on my bike back in the day, I found those super cheap models on Aliexpress. Asking price is 8€ for a pair, so there was no harm in giving those a try.

My plan was to design and 3D-print adapter plates to attach them to the windscreen stanchions. The mirrors come with all the fittings for a motorcycle handlebar. Their interface is a circular base with a single M6 screw.

The easy way was to use the middle retaining screw that hold the windscreen attached. As the frame is made of aluminium, using nylon fasteners will prevent any cross-threading. I had a close call with the first steel fasteners I had on hand and had to re-tap a side slightly. Be smart.

It took me a year and many iterations of the design to finally get an adapter plate that would really bring satisfaction. First models got the bracket firmly attached but the tight fastening of the screw was all that was preventing a rotation of the whole thing. The current model ensures the mirrors don't lift with speed or droop with bumpy roads - they were actually mostly lifting. This is achieved with a small peg that locks in the triangle opening in the provided brackets, as well as a side lip on the adapter plate to keep it aligned with the windscreen.

Dimensions of the fasteners are M5x35mm with Allen heads, in black nylon. Using M5 washers make them suitable in the 6mm holes of the mirror kit.

When the small mirrors are not used, the brass screws are replaced with M5x12mm countersunk screws with Philips heads, also in black nylon. Again to prevent any chance of damage to the windscreen due to cross-threading.

My first test-fit was with the brackets going upwards of their base. I didn't like that position as the mirrors were too high for my taste. So down they are.

An issue I didn't see coming was that the range of the knuckle joint didn't allow for the passenger-side mirror to rotate far enough to be adjusted to any useful angle. A custom spacer with very unnatural geometry was whipped out one half-drunken night. As it did fit on the first try, the prototype is still in use.

Future updates could include a cavity for a nut that would prevent losing the 35mm screws during storage, as well as location where the countersunk screws could be fixed when the mirrors are attached to the car.