The AT seat tube taillight is a generator-powered taillight made from milled aluminum and encompassing state of the art electronics. Inspired by the old French approach of placing the taillight on the seat tube, where it is protected yet visible.


The AT seat tube taillight is the sister to the AT fender taillight and features the same excellent Busch & Müller Seculite Plus circuitry with bright red LED emitter, voltage regulation (won't burn out if powered without a headlight) and powerful standlight (illuminates at full brightness for several minutes after stopping). The housing is shaped from CNC-milled 6061 aluminum and borrows its rounded shape from the fender taillight design, but is slightly reworked to be narrower and more teardrop shaped. It is available in a mirror-polished finish or limited-edition anodized black. The LED lens, shared with the AT fender taillight, is also a reflector, so the taillight meets legal requirements -- most state bicycle laws require a rear-facing red reflector. The lens extends slightly past the rear edge of the housing to provide side illumination.


Installs by threading onto the bike's M6 boss. Requires the bike to already have a brazed-on M6 boss mounted horizontally on the seat tube. Does not come with the braze-on boss, your frame builder will have to install one. Comes pre-wired with seven feet of our premium wire for a full frame run. Our premium wire meets military aircraft specification, abrasion resistant and super thin, which makes it suitable for routing through tight spaces like inside the bottom bracket shell. Check out our other installation hardware for integrated lighting here.


The AT seat tube taillight is 100% waterproof (and in fact can be submerged underwater), and has been tested to withstand the harshest environments.


Made in USA. 3 year warranty.


Polished finish:  $119 USD


Black anodized finish:  $119 USD