Top-load BMX stem designs

The V1 stem (2024) is a four-bolt top-load BMX stem based on the Odyssey DGN. I went for a geometric look and tried a vanishing chamfer, after seeing a vanishing fillet on another stem; it wasn't easy to do. These are renders and an exploded-view animation.

In 2025 I made a periodic lattice for a top-load BMX stem. I imported the bodies, converted them to implicit, picked a graph unit cell, and combined them with Boolean unions and intersections. Then I meshed the body and exported a 3MF ready for printing.

I printed several versions in grey and black: a body with a four-bolt faceplate and counterbored bolt holes, and a stem with faceted sides. I also printed the lattice faceplate from the workflow above, and rendered a shelled lattice version of the stem (v3) with lattice-filled pockets in the faceplate and the body. Most of my printed BMX and MTB stems were SLS PA12, and some were resin or FDM. I didn't ride any of them.

In spring 2025 I designed two BMX stems as part of a set of parts for TBD Bikes; one is a basic top-load stem made to be customizable. The rest of the set is on the MTB stem, crank arm and pedal pages.