No rear rack? No fenders? No worries! Enter the Schmidt seatpost dynamo tail light. It’s minimal looking, like a tiny ice cream sandwich designed by Brancusi. But unlike an ice cream sandwich, it’s not sticky, and it costs way more. Here’s the deal: it’s wicked bright, it’s small, and it’s durable. A machined aluminum housing and a stainless steel band make for a secure connection to the seatpost. The lens is tiny, the light is visible from 180 degrees. This light fits seatposts from 26.0-31.8, and includes two little rubber shims if you need them. It comes in a few fun colors. Some of these have clear lenses. Rest assured, the light itself is red.

The light comes with thick coaxial cable. That makes the wire more durable. It also makes it bigger, but that’s a small trade off.  Wire length is 190cm.

These lights come with everything you need to install them to a Schmidt headlight including directions.  

Mounting to a Sinewave Beacon?  Easiest thing to do is add two 2.8mm male crimps to the end of the coaxial wire, along with 3/16th heat shrink tubing, and some 1/8th inch heat shrink, then add two female 2.8 connectors to the Beacon's tail light leads.  Put 3/16th heat shrink tubing over those.  Then you can unplug the light if needed.  Here's a bad diagram!