This weekend I went on a four hour 145 mile loop through mountains and valleys with the return leg on highways. For most of the ride, it was 35C (95F). While moving, the mesh jacket and pants did a good job, but my helmet didn’t. It only allows for vizor fully closed, unlocked with a tiny gap or fully open. Anything in-between doesn’t stay in position. I fixed it by designing a vizor lock.

For maximum comfort while riding, all I need is a 1cm gap (3/8"). The solution is a 3d printed piece which mounts on the face of the helmet below vizor with 3M VRB tape and provides a hinged block to swing into position between the top of the helmet vizor opening and bottom of the vizor. When in up position, it is held in place by the vizor and provides a predictable opening. When swung down, it is out of the way and vizor closes and locks unimpeded.

The model is fully parameterized using new (to me) FreeCad Variable Sets and is printed in PETG on the side in one piece using a living hinge.

So far no issues! At highway speeds, the hinged block stays down under the air stream. When up, it provides a ton of airflow while the vizor is protecting my face. If it ever fails and I have to re-print it, I’ll probably streamline it to be lower profile, but I can’t really see it while riding, so until then, it doesn’t matter 😁

Summary

$0.10 of materials, an hour of my time, and the helmet is comfortable in the hottest weather while still fully protecting my face and eyes. Here is the stl model if you wish to print one for yourself: link.

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