The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

The New Hotness

  • Bafang BBS02: Speed Sensor Alignment

    My friend Gee’s bike is a Terry Symmetry, designed for (small) women, which poses challenges when mounting “normal size” components. The Bafang BBS02 speed sensor mount (with a reshaped nut) requires far more clearance between the chainstay and the wheel spokes than the Symmetry has:

    Bafang BBS02 Speed Sensor - OEM bracket
    Bafang BBS02 Speed Sensor – OEM bracket

    The chainstay is nearly parallel to the spokes, so the sensor fits equally poorly anywhere its cable will allow.

    The obvious solution is to reverse the mount and stick it to the outside of the chainstay, but it’s not mmmm symmetric: the other end is closed. Use a pull saw to cut off the closed end, stick the sensor post in the other way, and then it fits fine:

    Bafang BBS02 Speed Sensor - reversed bracket - top
    Bafang BBS02 Speed Sensor – reversed bracket – top

    The sawed-off mount is visible from below:

    Bafang BBS02 Speed Sensor - reversed bracket - bottom
    Bafang BBS02 Speed Sensor – reversed bracket – bottom

    It looks fine from the outside:

    Bafang BBS02 Speed Sensor - reversed bracket - left side
    PXL_20210620_160950653 – Bafang BBS02 Speed Sensor – reversed bracket – left side

    Mad props to Bafang for the LED showing when the magnet is properly positioned.