Xiaomi M365 Bicycle Trailer Hitch/Adapter

This is a hitch I designed to fit the four available holes on the right side of the scooter underneath the fairing that covers the rear axle. Two of the holes in the scooter frame are already tapped with M3 machine screw threads and an M3 screw fits them perfectly, the other two are slightly wider (maybe M4 holes?) and are not tapped, however M3 screws with a nut on the backside and washers still secures the piece firmly. The four screw points are probably unnecessary and you may be able to get away with just the two outside ones.

Requires four (or just two) M3 machine screws (approximately 18 mm long), four (or just two) M3 washers, and an optional two M3 nuts. Extender piece requires two M3 machine screws (approximately 18 mm long), four M3 washers, and two M3 nuts.

The hole at the top of the hitch is 10 mm. I am not entirely sure if this is universal for bike trailers, however the one I designed it for (a Petique pet stroller bicycle adapter) is 10 mm.

Depending on your needs, the first part alone may be all that is necessary, however I have designed an extension to this piece to help raise the trailer arm mounting point (the 10 mm hole) to approximately 13" above the ground (as opposed to approximately 9.5" without the extender). This will keep your trailer level as I believe bike trailers are designed for about a 26" wheeled bicycle. There is a solid and a ribbed model available for the extender, each one has the same geometry except for the ribbing. I chose to upload both as I realized the ribbed version may actually be weaker than the solid version depending on how many walls and how much infill you use, so pick whatever looks strongest when slicing.

The cool thing is that this model will work whether you print the first piece or both pieces, as the extension fits into the geometry already in the first part and uses two additional screw points to secure the connection.

The drawback to this design is that it's somewhat flimsy when torqued. I am printing this out of PETG and I recommend you do the same for maximum strength.

Fusion 360 file is included if you want it. I suck at maintaining and documenting my sketches/bodies so be warned.

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